Geography- Mark

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

Variations in river discharge

Variations influence the energy of a river and in turn the river land forms

A watershed

A watershed is an area of highland forming the edge of a river basin

Damage to peatland-drainage

Around a quarter of Enlgish peatland is under cultvation. e.g. East Anglian fens were drained for farming No longer waterlogged, the peat shrank, decomposed and became eroded by the wind released more co2 in the atmosphere

Blanket Peatlands

Blanket/upland lanscapes Form where rainfall is very frequent and cloud cover is high Rainfall, snow and mist are the sole source of scarce nutrients; the plants that can tolerate these conditions include bog mosses and cotton grasses, along with heathers Golden plover and dunlin nest in these remote areas, as do hen harriers and short eared owls

Northumberland Wildlife trust

Bonder Mires restoration project- the longest running peatland restoration project of all- and over 2850 ha. Border Mire: peat bog sites adjacent to Kielder Forest Access is difficult > remove location/ a long walking over terrain The Border Mires made up of peat (blanket bog) - peat stores carbon and reduces the effect of global warming Plants (cotton grasses/ Sphagnum moss) Insects (black darter, Golden-ringed dragonflies) Kielder Forest store more water than the reservoir and release it steadily, moderating flows and reducing flash floods Restoration reduces erosion and thus the amount of peat sediment in the water (river Tyre / Irthing) Helping to buffer the effects of flash flooding and lack of water in dry summers through regulation of flows This kind of properly funtioning upland habitat helps lower river systems.

Loughor - upper

Upper - infiltration ↑- flat land/ no urban area - run off↓, but all three types can happen as the rock is permeable - ↑ interception as there is vegetation - ↑ evapotranspiration.

Climate chagne intensifies drought conditions

According to Colombia University, Global warming has contributed between 8% and 27% to the severity of the Californian Drought. Global warming has contributed to 50% of the temperature increase in drought conditions during 2012 to 2014. Overall, in the absence of global warming, the recent drought would have been approximately 15 to 20% less severe than it was. In addition, after four years of drought, the snowpack in the Sierra Nevada mountains of California record low. According to the same study global warming is to blame for 25% loss of snowpack beyond the natural change in climate.

Field capacity

Field capacity is when the soil is fully saturated. All available pore spaces between the soil particles are filled with water. Any further falling onto the ground cannot infiltrate into the soil and forms overland flow.

Terristrial Ocean feed back

Increased oceanic temperature due to green house Water evaporate (causing more albedo, acting as a green house gas) CO2 less dissolvedi into water Warming tundra emits CO2 and Methane More co2 water and methane increases temperatrues

Extreme rainfall caused due to GHG

extreme high intensity rainfallin 2007 led to pluvial flooding in some British cities caused 3 billion damage.

The Source

the source is where a river begins

Loughor- middle

upper-middle - urban area (runoff ↑, infiltration ↓) and the land is steep. - ↓ evapotranspiration - less vegetation ↓ interception lower-middle - permeable rocks > throughflow and ground flow can happen. - fewer buildings, ↑ infiltration - more vegetation, ↑ evapotranspiration - ↑ interception

Spatial variation- in the tundra region of Northern Canada and Russia

- 250mm per year - most river discharge takes place in a short period of intense runoff in the early summer when there is a sudden melt of the winter snow. - Discharge is high at this time, and , as temperatures are low, there is little vegetation so evapotranspiration is minimal. - Daily basis, there are often short term fluctuations - Discharges are low overnight and in the early morning because little melting takes place. - During the course of the day, as the sun melts the ice , river discharges increase to a peak in the late afternoon, only to decrease as the temperatures fall and melting ceases

Forming of glaciers

- A glacier forms when snow accumulates over time turns to ice and begins to flow outwards and downwards under the pressure of its own weight. - In polar and high-altitude alpine regions, glaciers generally accumulate more snow in the winter than they lose in the summer for melting and evaporation. - Each year's snowfalls continue to compact the underlying areas, and the snow grains become larger ice crystals which are randomly oriented in connected air spaces. - These ice crystals can eventually grow to become several centimetres in diameter. - As compression continues and the ice crystal grows, the air spaces in the layers decrease, becoming small and isolated. - This compaction compresses more air spaces out of the snowpack and compacts the remaining air into bubbles. - At the greater depth (hundreds of metres), the air in these bubbles is squeezed into the crystal structure of the ice. - Thus, dense glacial ice has no air bubbles but contains trapped air nevertheless. - Glacier retreat, melt and ablation result from increasing temperature, evaporation, and wind scoring. - As long as snow accumulation equals or is greater than melt and ablation, a glacier will remain in balance or even grow. Once winter snowfall decreases or summer melt increases, the glacier will begin to retreat.

La nina event

- A la Nina period may be described as an exaggerated normal year "very strong walker loop" - There are extremely strong trade winds pushing warm water westwards and raising sea level by up to a meter higher in Indonesia and the Philippines. - Deep low-pressure develops over Southeast Asia, causing very heavy rain on account of the strong convectional uplift from warmer than usual seas. - On the Eastern Side of the Pacific, there is a strong upwelling of cold water off the coast of Pero -Higher than the average pressure that occurs here causes extreme drought in the semi-arid areas of Northern Chile and Peru. Australia (2011) Flashflood+ sea level rises 2.35 billion dollars damage 60% increase in reservoir + lake levels 2011 Peru 75% decrease in farm crops

the 21,000 year wobble- glacials interglacials

- As the earth slowly wobbles in space, its axis describes a circle once in every 21,000 years. - At present, the orbit places the Earth closest to the Sun in the northern hemisphere's winter and furthest away in summer. - This tends to make winters mild and summer cool - These are ideal conditions for glacials to develop. - The position was in reverse 12,000 years ago and this has contributed to our present warm interglacials.

Factors affecting river discharge and regime- Drainage density

- Drainage density is the number of surface streams in a drainage basin. - High densities are found in areas of impermeable rock and clays. - The higher the density, the faster the water reaches, the river channel causing rapid changes in the discharge of a river. - RIvers with rapidly changing discharges are sometimes called flashy - Such rivers have short lag times and high peak discharges. therefore more prone to flooding

El nino event ( En Nino Southerm Oscillation )

- El Nino occurs periodically- on average every two to seven years - An El Nino lasts for 12~18 months - In contrast to normal conditions there is a reversal, in the equatorial Pacific region, in pressure, precipitation and often winds and ocean currents - Pressure rises over the western Pacific and falls over the eastern Pacific. - The descending air, now over South-East Asia, gives that region much drier conditions that it usually experiences, even causing droughts. - In contrast, the air over the eastern Pacific is now rising, giving much wetter conditions in places like Peru which normally experience desert conditions. - The change in the direction of the trade winds means that surface water tends to be pushed eastwards so that sea-level in Southeast Asia falls, while it rises in tropical South America. - Surface water temperature in excess of 28 degrees extend much further eastwards and the upwelling of cold water off South America is reduced, allowing sea temperatures to rise up to 6 degrees. - The warmer water in the eastern Pacific lacks oxygen, nutrients and therefore plankton and so has an adverse effect on Peru's fishing industries. Australia (2015)= highest record ever 9 days straight above 35 degrees 5% reduction in rainfall. Peru 2017- Flashflood 113 died 40,000 homes destroyed

How might glacial and interglacial events influence the amount of water in certain stores

- Interglacial shows the warm phase therefore, the Ice on the earth's surface is at the low rate (10%)which takes approximately 2.2% of the global water - Therefore, more abundant liquid/ground water stores. For example, 97% of the water stored in ocean. - This increases the transfer process such as evaporation, infiltration, and runoff. More water on the surface of ocean will evaporate, hence more precipitation on the land, causing more infiltration and runoff ( surface flow, throughflow, and ground flow) - Therefore, the amount of water store will rise. However, when it is glacial, the average temperature will drop, increasing amount of ice in polar and alpine regions. The more ice will reflect the solar radiation, hence the less amount of the solar radiation will be received on the land, causing more amount of ice, which will cause albedo effect. - the glacial shows more ice that 30% of ice covers the land surface which holds 6 to 8% of the global water. - this reduces the liquid water source as the amount of ice increased which drops the sea level up to 150m - This will reduce the transfer because even though some evaporation will occur from the liquid water, if this ends up being in the glacial area, the precipitation will continue as a form of snow, which increases the size of glaciers whereas it reduces amount of liquid water stores.

Glacials and Interglacials

- It appears that roughly every 100,000 years in the Earth's history. There have been major periods of Ice activity. - There have been fluctuations in global temperature which have led to cold phases(glacials) and warm phases(interglacials) - In last few decades, eidence obtained from cores taken from ocean floor deposits and polar icecaps has led glociologists to claim that there have been more than 20 glacials. When the ice reached its maximum extent, it is estimated that it covered 30% of the Earth's surface (10% today). However, its effect was not only felt in polar latitudes and mountainous areas for each time the ice advanced, there was a change in global climatic belts. e.g) 18000 years ago (maximum advance within the last glacial), ice covered as far south as the Bristol channel, the Midlands and Norfolk. The south part of britain experienced tundra conditions.

Loughor- Case study background information

- Loughor river drains the remote uplands of the Black Mountain in the northeast of the catchment area - It has rural nature( some urban industrial area) - The precipitation average is 1500mm which is higher than the welsh region average of 1310mm - River descends steeply/ responds rapidly to heavy rainfall - Primarily "carboniferous strata (pennant sandstone _ Millstone grit)" - These permeable rocks form a flow at Llygad Llwchwr, Source of a major public water supply abtraction

Normal Year (el nino, la nina cycle)

- Under normal atmospheric conditions, pressure rises over the east pacific ocean and falls over the western Pacific ocean ( towards Indonesia and the Philippines.) - The descending air over the eastern Pacific gives the clear, dry conditions that create the Atacama desert in Peru -. While the warm moist ascending air over the western Pacific gives that region heavy convectional rainfall. - This movement of air creates a circulation cell, Walker circulation, in which the upper air moves from west to east and the surface air from east to west as the trade winds. - The trade winds push surface water westwards so that sea-level in the Philippines is normally 60cm higher than in Panama and Columbia - THey allow water to remain near to the ocean surface where it can gradually heat. - This gives the western Pacific the world's highest ocean temperature, above 28 degree - In contrast, as warm water is pushed away from South America; it is replaced by an upwelling of colder, nutrient-rich water - This colder water lowers temperatures, sometimes below 20 degrees, but provides the plentiful supply of plankton which forms the basis of Peru's fishing industries.

Why is excessive runoff generated in specific climate zones?- Case study monsoon rainfall in Bangladesh, June 2017)- the positive impacts of monsoons

- agriculture relies on the yearly rain - many areas in South Eastern countries do not have large irrigation systems surrounding lakes, rivers or snowmelt areas. - Aquifers, or supplies of underground water, are shallow. - The summer monsoon fills wells and aquifers for the rest of the year. > rice and tea are crops rely on summer monsoon. > Dairy farms ( India is the largest milk producer in the world) also depend on the monsoon rains to keep cows healthy and well-fed. - industries also rely on monsoon a great deal of electricity in the region is produced by hydroelectric power plants, which are driven by water collected during the monsoons. Electricity power in hospitals, schools and businesses that help the economies these areas to develop. When summer monsoon is late or weak, the regional economy suffers. Fewer people can grow their own food, and large agribusinesses do not have products to sell. Government should import food electricity becomes more expensive, sometimes limiting development to large businesses and wealthy individuals.

Fuel conbustion

- fossil fuels being burnt to supply electricity, transport 80% of global energy comes from the use of fossil fuel. - biomass (wood, plants, peat, straw)

Why is excessive runoff generated in specific climate zones?- Case study monsoon rainfall in Bangladesh, June 2017)- the negative impacts of monsoons

- heavy summer monsoons can cause great damage. - residents of such urban areas as Mumbai are used to the streets flooding with almost half a meter of water every summer. - Mumbai, entire neighbourhoods can be drowned. - in rural areas, mudslides can bury villages and destroy crops. - In 2017, monsoon floods in Eastern Bangladesh rain fell totally over 300mm in a week, causing deadly mudslides, killing at least 156 people and destroying 5000 homes. - Mudslides also damaged or blocked roads in the remote and hilly areas

Collision and coalescence

- in many parts of the world, the air is too warm for ice crystals to form and therefore rain and snow canot develop following the bergeron process - instread, tiny droplets form as they collide into one another creating larger and larger droplets. - the coalescence of droplets into a larger droplet can only take place if the droplets have an opposite electrical charge - This means if one droplet has a positive charge, then they will coalesce upon collision - Otherwise, they will just bounce off of one another.

Bergeron Findeison process

- it takes place when ice crystals form high in the cloud tops. - microscopic ice crystals attract more water vapour, causing them to increase in size, the vapour pressure drops - this allows surrounding water droplets to evaporate, becoming smaller and smaller as the ice crystal grows - eventually, these ice crystals become large and heavy enough to fall towards the Earth's surface. As they do, they pass through the lower, warmer portion of clouds, attracting, even more, water vapour and growing larger still. - These ice crystal can then fall to the surface as snow or they can melt, becoming rain drops. - it is believed that most precipitation happens in this manner.

1. The 100,000 years stretch - glacials interglacials

- over a timescale of 100,000 years, the earth's orbit stretches from being nearly circular to elliptical shape and back again - this affects the amount of radiation received from the Sun - Interglacials occur when the orbit is almost circular and glacials when it is a more elliptical shape

Spatial variation- in the sub tropical hot desert

- precipitation is low 250mm - very high rate of evapotranspiration therefore minimal river discharge - most channel runoff is only short-lived in the form of flash floods following a heavy rainstorm and over a short distances as the water quickly infiltrates into the sandy soil.

Spatial variations (changes from place to place)

- rivers in different geographical locations have different patterns of discharge - the discharge is affected by the climate of the region as well as other factors

Temporal variations (change over time)

- short-term fluctuations in discharge eg_ increased discharge following heavy or Snowbelt - Medium-term variations eg_ seasonal variations such as less discharge when interception is higher in a deciduous forest in summer - Long-term changes in discharge eg_ as a result of climate change or change in land use

Prolonged and Intense stroms in UK 2015-2016

- storm "desmond" brought the flooding to Cumbria and Lancashire - Honister Pass, in Cumbria, received 341.4mm in 24 hours, breaking all previous records and far exceeding predicted level of 150~200 mm. - The 48 hour record was broken at Thirlmere, where 405mm rainfall was recorded.

General ideas about glaciers

- the most of the glaciers located in the poles but exists on all of the continents - The specific climate is required such as high snowfall in winter and cool temperatures in summer that accumulate the snow in winter and not lost during the summer. - Typically prevail in polar and high alpine regions. - The amount of precipitation is important. For example, Antarctica, low temperatures are ideal for the glacier growth, but the small amount of net annual precipitation causes the glaciers to grow very slowly, or even to disappear due to an evaporation of the ice ( sublimation)

Interception

- when it rains moisture will collect on leaves and branches as interception storage - the moisture may evaporate never reaching the ground surface - if it rains continuously for some time, the vegetation may become saturated and the water will begin to reach the ground by throughfall, stemflow and drip. - the greatest interception at the beginning of a storm, reduced as the precipitation continues. - vegetation is most efficient in an interception and evaporating moisture when rainfall is in light, sporadic snows rather than continuous heavy rainfall. - conifers intercept more than deciduous tress. - 30% of precipitaion may be intercepted in forest, hence the soil erosion is limited in forest.

What are the human cuases of water cycle deficit?- economic factors- Agricultural demand for water

1. 80% pumped water used by agriculture 2. California produces nearly half of US-grown fruits nuts and vegetables. 3. US consumers regularly purchase several crops produced solely in California, including almonds, grapes, strawberries, lettuce and tomatoes, as well as milk and cattle. The most water thirsty crops are industrially produced meat and dairy and the fodder needed to sustain them. 80% of almond in the world produced in California. Providing water for agricultural, industrial and home use has required massive efforts to channel water from rivers in Northern California and the Colorado River to where it was needed in the agricultural areas of the Central Valley. To irrigate an acre of corn requires 1 million gallons of water during the 3 to the 4-month growing season. Nearly all of Californias cropland and large percentages of forage and pasture land are irrigated. The total land area currently irrigated in California is about 7.6 million acres. Much of irrigation water is being applied to low value crops like forage alfalfa and rice. This practice is only posible because the federal government provides generous subsidies, estimated at approximtely 1.5. billion to pay for the irrigation. Tis situation will change in the future when Clifornia agricultural requirements compete more intensely with the needs of a rapidly growing human population and industry. Lastly, the over abstraction of water due to agriculture land to aquifers and other ground water sources becoming more saline and polluted reducing the water quality. .

over abstraction of ground water problems

1. Aquifers become depleted to very low levels. Aquifers take time to naturally recharge. 2. Draining aquifers to the point where water quality deteriorates 3. Groundwater extaction can cause subsidence or sinking of the land above the aquifers, which can lead to break in infrastructures like roads and buildings and the buckling of canals. 4. Sinking or subsidence of land above aquifers can damage the ability of aquifers to store water in the future. Therefore permanently damaging this crucial underground store of water. 5. Aquifers as they become depleted, they can become contaminated by inflowing salt water in more coastal locations if the water table drops below sea level Over abstraction means that groundwater sources never break even and they decline over time This is a critical human cause of drought in the USA because 15 to 20% of water used is coming from groundwater in the Central Valley.

Causes of precipitation

1. Bergeron Findeisen process Collision and coalescence

Flows and transfers within the hydrological cycle

1. Evapotranspiration 2. interception 3. infiltration 4. runoff

Outputs from the drainage basin

1. The river draining into a lake or the sea at its mouth 2. Water percolating deep underground into groundwater stores where it is effectively lost from the system. 3. Evapotranspiration * the combination of these inputs, stores and outputs of water from the system can sometimes be referred to as the mass balance.

WHy the Ganges or GMB is considered as having a comlex river regime?

1. Three rivers meet together 2. Three different discharge regimes (affected by monsoon and glociers)

Ganges river case study - Physical factors affecting the river regime

1. Tropical monsoon: mean temperature higher than 18, wet &dry season, seasonal change in wind direction. - In Asia, during the summer, there is an onshore flow of air ( Ocean to land) - This takes warm moist unstable air from the Indian Ocean, bringing heavy convectional rain to India - Rainfall totals are further increased by the uplift of this air over the foothills of the Himalaya and by intense convectional rainfall - In the winter, an offshore air flow is prevalent (land to water) - The change in direction is due to the difference in the way water and land heat. - The wind blows from Northeast India towards the South and this brings dry conditions to the India as the winds travel over land and not the sea. 2. Glaciers The Himalayan glaciers and annual snow cover that accumulates in the winter and melt during the summer constitute the main water source of the Ganges. The Ganges has a complex river regime as well as the three rivers which interconnect (Ganges, Megha and Brahmaputra), there are 50 smaller river and tributaries.

Stores in the drainage basin hydrological cycle

1. on the surface such as rivers, lakes, streams and puddles 2. in the soil 3. deep below the ground surface as ground water 4. vegetation after a period of precipitation.

Why is excessive runoff generated in specific climate zones?- Case study monsoon rainfall in Bangladesh, June 2017)- causes

1. pressure and wind in summer, moist air is carried northwards by the wind from the Indian Ocean over the Indian subcontinent, which generates the rains - This happens because the summer winds originate in an area of high pressure in the southern Indian Ocean and cross the equator before blowing onshore and area of lower pressure - Winds blow from areas of high to areas of low pressure and so the warm moist air moves northward and acquires abundant moisture from the ocean which fuels convection and storm cloud development during the Summer Monsoon. 2. Pressure differents are caused by the land heating up and cooling down disproportionately to the sea (oceans warm and cool more slowly than land) this inequality leads to the creation of pressure gradients and thus winds. 3. ITCZ (intertropical convergence zone) - the seasonal migration of the ITCZ and its wind belts as it moves north and south - This movement is in response to seasonal differences in pressure gradient due to the changes in solar energy received throughout the year. 4. Mountain chains - the presence of huge mountain chains such as the Himalayas results in orographic enhancement of rainfall because air masses are forced to rise and condense - they can also increase low-level convergence of air, creating a zone of rising air when moisture-laden clouds collide forcing water droplets to grow and fall. - therefore, mountain chains can include exceptionally high rainfall in convergence zones. e.g Assam in North India can receive greater than 10,000 mm of rain annually, 6 times that which falls on the coastal zones.

Ocean acidification

1/3 of CO2 has been released by human activity has diffused into the oceans Had not occured, atmospheric concentrations of CO2 would be even higher than they are now The incresed acidity of ocean has harmful effects for coral reef organisms and other sensitive species Carbonic acid reacts with carbonate ions to form bicarbonate However, carbonate ions are what coral needs to create their calcium carbonate shells With less carbonate available, the animal needs to expend more energy to build their shells Shells end up being thinner

Soil

45% of minerals (inorganic carbon) 50% of air and water 5% of organic matter (10~20% are organisms) 80~90% are humus ( partly decomposed materials)

Prolonged and Intense stroms in UK 2015-2016 - causes

4th ~6th of December, heavy rainfall led to widespread flooding in Cumbria and across other parts of Northern Britian. - The flooding resulted from some exceptionally high rainfall totals across the Cumbrian fells, exceeding 300mm and breaking existing UK rainfall record - Rainfall was brought by Frontal Systems when warm air meets a cold air mass. but also > atmospheric rivers of water vapour > El NIno > Climate Change

What are the human cuases of water cycle deficit?- over abstraction of ground water

80% of all water used inCalifornia is used for agriculture The Central Valley crops > 25% of food consumed in USA Farmers started to use more ground water aquifers because river levels fed by melting snowpack were declining In 2014, California relied on water pumped (75%) In 2011, it was only 30% Water abstraction is high than the water is naturally replaced through percolation after rainfall.

A channel

A channel is where a river flows

Flood hydrograph

A hydrograph shows the discharge of a river measured at a particular point, usually a gauging station It shows the response of a drainage basin to a specific rainfall event Antecedent flow ; the discharge of the river before the rainstorm when the rain starts to fall, the river discharge remains largely the same Although some of the rain falls directly into the channel, most falls in other parts of the drainage basin and takes some time to reach the channel Once overland flow begins after interception storage and the infiltration rate are exceeded, and later, through flow, the river's discharge beings to increase. This shows on the hydro graph as the rising limb The steeper the rising limb, the faster the water is reaching the drainage basin. The peak discharge occurs when the river reaches its highest level. The period between maximum precipitation and the peak discharge is called the lag time. In river basins with a short lag time there is often a high peak discharge and the river is more prone to flooding The falling or receding limb shows when discharge decreases. This is usually less steep then the rising limb because although overland flow may have stopped, the through flow counties slowly. Eventually, when all of the water from the rainstorm has passed through the drainage basin, the discharge level returns to the base flow level. Base flow is the most significant flow over a long period reflecting seasonal changes in the climate and vegetation Base flow responds very slowly during a period of rain yet maintains the flow of a river during a drought.

Why is excessive runoff generated in specific climate zones?- Case study monsoon rainfall in Bangladesh, June 2017)

A monsoon is a seasonal change in the direction of the prevailing or strongest winds of a region Monsoon cause wet and dry seasons throughout much of the tropics. Monsoons are most often associated with the Indian Ocean. The summer Monsoon and winter monsoon determine the climate for most of India and Southeast Asia.

A mouth

A mouth is where a river flows into a lake or sea

Afforestation

Afforestation involves planting trees in deforested areas that have never been forested. New trees out as carbon sinks help with climate change mitigation and help reduce flood risk schemes. 1. he UN reducing emissions from deforestation and forest degradation (REDD) scheme. Incentives for developing countries to conserve their rainforests by placing monatary value on forest conservation 2. The UK forestry comission in 1919. To increase timber supply through policy and land use change. Marginal areas of grassland, heather and moorland to grow connifurous forest e.g. the Brecon beacons. Increase in commercial trees can increase carbon storage if it replaces grassland. However, it may store less carbon than natural forest biome communities do. This is because monoculture (one tree) forests lack biodiversity and provide fewer habitats for other plant and animal speices.

Is the drought in California finished?

After more than five years of drought in California, 2017 has been above average precipitation and snowpack On April 7, 2017, Gov Jerry Brown officially ended the drought state of emergency in all California countries. Surface water: precipitation in water 2017 has fined the majority of California's major reservoirs to above historic average levels. Likewise, as the USGS streamgage network shows, flows in the majority of the streams have been at or above average for most of the last 4 months. This indicates that most of California's rivers, creeks, lakes and reservoirs are in good condition Snowpack: on average, the Sierra Nevada snowpack supplies about 30 percent of California's water needs as it melts in the spring and summer A series of back to back atmospheric river storms blanketed the Sierra Nevada in January and February 2017. As of May 31, 2017, state-wide snow accumulation data indicated that snowpack in the north central and Southern Sierra is 190% of normal for this date. Ground water: ground water aquifers recover much more slowly than surface water and are limited, among other things by how much and how fast water can recharge. Unlike surface water, which can recover during a few days of heavy precipitation , groundwater aquifer recovery often takes years or decades. Groundwater systems are also relied upon more heavily during times of drought In addition, in many areas of the state, groundwater systems have been depleted for long periods even between droughts - that they have not recovered from. Excessive, lon-term groundwater over use resulting in groundwater dpeletion can cause subsidence and permanent loss of ground water storage as well as water quality degradation and seawater intrution. These long term impacts on ground water have not beed remedied by the recent weatther. If recovery is possible, if will likely take severay years to accomplish.

Agricultural activity and its affect on carbon cycle

Agriculture affects both biomass carbon storage of land and the amount of soil organic carbon (SOC) which is the carbon associated with soil organic matter (made up of humus, such as decomposed palnt and animal materials) Globally, clearing natural vegetation for agriculture brings a large reduction in SOC levels. Because of poor anagement practices. In many farmed areas, soil carbon levels have fallen by 50% compared with pre-agricultural periods. Land erosion and soil erosion problems occures ( Dust Bowl in 1920s and 1930s) In this Great Plains, wind erosion stripped the top soil from 65 million hectares of over-cultivated land, leading to enormous loss of soil carbon store capacity Positive gains Addition of manure, plant debris, composts and boisolids from sewage to agricultural soils All are high in organic carbon and represent additional carbon inputs to the soil subsystem.

Orographic relief rainfall

Air may be forced to rise over barriers such as mountains. As it rises and cools, it condenses and forms rain. There is often a rain shadow effect where the ley side of the mountains receive little to no rain.

Methane> posive feedback

Alaska, have risen by 4 degree celcius since the 1960s, and try as much as 10 in winter months Magnified over time by positive feedback loops As the atmosphere warms, more permafrost is expected to melt This releases large amount of Methane (stored in permafrost is more than double the amount of carbon currently in the atmosphere) The atmosphere will warm up even quicker Even more methane will be released due to more melting permafrost

Damage to peatland- Grazing

Almost a third of English peatlands now support invasive egetation speices not originally found there sequestration- may have slowed These are often areas affected by livestock grazing.

Yorkshire wildlife trust

An integral part of the Yorkshire peat partnership Working to restore and conserve upland peat resource in order to ensure the long-term future these unique and valuable habitats Area includes the uplands of the Yorshire Dales National park, Nidderdale area of outstanding natural beauty, North york moors national park and areas of the South penines, north of the rier calder Yorshire: 70000 hactares of upland peat soil 4350km of drainage channels have been incised Aim to increase the amount of peatland restoration activity In May 2013, It has restored a quater of the peatland (protect vital habitats & cut global warming) 29500 tonnes of the damaging greenhouse gas Co2 prevented from being emitted, a major cause of global warming (equivalent to carbon emitted by 62000 UK household)

Why is excessive runoff generated in specific climate zones?- Case study monsoon rainfall in Bangladesh, June 2017) - summer monsoon

Associated with heavy rainfall (April-September) As winter ends, warm, moist air from the Southwest Indian Ocean blows towards countries like India, Sri Lanka, Bangladesh, and Myanmar. The summer monsoon arrives in southern India in late May or early June and gradually advances northwards and westwards, reaching Pakistan by early July. The norhtern extent of the summer monsoon in India and Nepal is governed by the presence of the Himalayas. Monsoon storm systems typically rise 10km into the air, and the great Himalayan peaks rise to a substantial proportion of this ( commonly 7km) Thus, they act as a major topographic barrier, preventing the northward flow of moist air and maintaining the arid climate of Tibet.

Carbon sequestration

At short-term and local scales, several important processes are involved in Carbon sequestration and release. These are often referred to as Fast corban cycle processes. Carbon sequestration is the natural capture and storage of Carbon Dioxide from the atmosphere trhow physical or biological processes such as photosynthesis

Factors affecting river discharge and regime

Basin size, shape and relief

What are the human cuases of water cycle deficit?- demographic factors

California is the most populus state. 2 million in 1900 to 37.8 million in 2010, 50 million by 2015. Los Angeles 6 million in 1960 to 13 million in 2014. Urban water use increases as the state's population in the major cities increase. Urban water use is influenced by development patterns and changes to the state's employment factor : manufacturing jobs being replaced by service sector job. As consumers become more economically developed, the demand for water per capita increases. Substantially with increasing use of sprinklers, dishwashers, swimming pools and the watering of golf courses. In the past, Californians have used water wastefully in part due to the low prices for water. Spatial imbalance of high population densities in the South with low precipitation rates is the major challenge. Climate change further increases urban water demands. In particular, high temperatures and altered precipitation patterns will increase evaporation and transpiration rates and thus increase demand for water use for showers, to water golf courses and increased water use in hospital and offices.

Drought in the state of California - USA

California suffered a severe drought from 2012 to 2016. In 2015, over 71% of the state was experiencing extreme drought conditions, and 46% was experiencing exceptional drought.

Role of citizens about the afforestation

Carbon offsetting used to marry business principles with nevironmental goods It is a way of compensating for the emissions by funding an equivalent CO2 saving elsewhere e.g. plant a tree after taking an aeroplane flight.

Cloud formation

Clouds form in the atmosphere because air containing water vapour rises and cools The key to this process is that air near the Earth's surface is warmed by solar radiation; this causes air to rise As air rises and cools, the water in it can condense out, forming clouds. This is when water vapour in the air changed into liquid water The water molecules condense on tiny particles in the air (dust, smoke and salt) called condensation nucleai Alternatively, if condensation is taking place near the ground because the temperature of the air is lowered to the dew point then condensation occurs on surfaces like grass blades, windows and leaves If clouds drift into the air below freezing point , then the water droplets become hail or snow.

Factors affecting river discharge and regime- Precipitation- intensity

Convectional thunderstorms may exceed the infiltration capacity of the soil causing large quantities of surface runoff and the rapid rise in river discharge.

Agricultural management for soil subsystem

Crop management: irrigation, improved crop rotation Pasture management: Fertilizer management grazing management Improved grass species Introduction of lengarves. Organic amendments: animal manure, recycled plant remains.

Extreme rainfall (hurricanes, typhoons) caused due to GHG- Yasi

Cyclone Yasi, Australia, Febrauary 2011 February 3rd 2011- Australia Cat 5 : 186 mph winds 300 miles wide 20 ft storm surge 10,000 homes destroyed 0 deaths Sucessful early warning systems and evacuation Total damage (3.6 billion)

Decomposition

Death+decay of organic cells Breatdown of cells releases CO2 back to the soil Physical (scotching), chemical (leaching), biological (feeding) bacteria+fungi releases CO2 Increases when in humid location decreases when in cold location

How might El Nino and La Nina events influence the amount of water in certain stores?

During El Nino Australia - drought cause - less water in store ( the soil moisture, the puddles, moisture - this reduces the number of stores - However, groundwater stores may not be affected S. America - More rainfall & precipitation - more water transfers & stores as greater water availability - The more water will be stored in the soil, vegetation and the atmosphere. During La Nina- Australia - The trade wind goes East to West much stronger and the low pressures at Australia, causing much stronger & higher amount of rainfall - transfer increased - this causes the water to be stored more in the soil, vegetation and in the atmosphere and flood can cause the underground stores to recharge. During La Nina- South Ameirca - The high pressure in South America, the availability of water reduces and they will experience the dry whether and drought which causes the stroes to reduce ( less water in the surface, soil, vegetation) - However, the ground water may not change.

Meterorological causes of droughts- UK summer drought 1976- causes

During the summer of 1976 the jet stream was further north than usual. The jet stream consists of ribbons of very strong winds which move weather systems around the globe. This enabled a high pressure system (bring hot weather) to domiate over the Uk during the summer. Severe droughts in the united kingdom will need to have the high pressure (brings hot dry weather) in charge of the weather for a nexteded period, commonly for weeks or even months at a time. A blcking anticyclone, a high pressure system forces other low pressure systems around it, usually to the northwest. In June and July, both high pressure which brings hot weather and southerly winds were more frequently than susual. August was generally the driest month of the summer, and was characterised by exceptionally dominant high pressure.

Cryosphere feedback positive

Earth has grown warmer, temperature change has accelerated because of ice cover loss Ice has high albedo of 80% The water has lower albedo, absorbing heat warms up Melt even more sea ice, more areas of sea open Warm air> higher reflecting of ice> more sea ice melt> less albedo> less light heat reflected> more heat absorbed in sea> warming water( thus human climate change, thermal pollution) even small changes in sea ice coverage has a potentially significant impact on global climate

Inputs into a drainage basin

Energy from the sun, precipitation

Flows and transfers within the hydrological cycle- evapotranspiration

Evapotranspiration > evaporation+transpiration that cannot be separated easily.

Impacts of rising GHG emissions on the water cycle

Evidence of water cycle affected by increased amount of carbon Amount, type and patterns of precipitation including extreme weather events River discharge Sea level rise ocean acidification As temperature rises, more evaporation in ocean occurs. UK annual average rainfall has not changed since the 18th c, however, in the last 30 years more winter rainfall has fallen in heavy events.

Fen Pealands

Form where groundwater meets the surface at springs, hollow, or the edge of open water The type of fen vegetation vary greatly on the quality of water ( mix of reeds, sedges, tall herbs insectivrous plants like sundews) Animals include bitterns, bearded tits, curlew and snipe and a wide range of invertebrates such as the swallowtail butterfly and white-faced darter dragonfly

Frontal cyclonic rainfall

Frontal rainfall occurs when warm air meets cold air The warm air being lighter and less dense is forced to rise over the denser coller air As it rises and cools, it condenses and forms rain Warm air is forced upwards as it is undercut by cold air. The warm air will rise, cool, and condense the result is cloud and rainfall

Global warming

Global warming is caused by increased greenhouse gas (GHG) emission, and humans are the cause of this CO2 emissions have been rising since 1750, from 280ppm to 406ppm at the start of 2017 (45% increase) higher population growth and economic development have led to wroldwide use of carbon-rich fossil fuels as an energy source; widespread deforestation; cement manufacturing; enhanced methane emissions from livestock and the decomposition of organic wastes in landfill sites HOckeystick trendline measurment at Mauna Lao> every year since 1950, a rise each year of around 1 to 2 ppm

Ground water

Ground water is deeper and slower- the delay between rainfall and water reaching ground water. It is continuous, providing a constant supply of water into river channels( even in periods of drought) Once in the river, the water forms channel storage before ultimately discharged into sea and lost from drainage basin The channel acts both store and transfer of water During a flood event, the river channel is filled with water and forms a major store in the system.

Factors affecting river discharge and regime- temperature

High temperatures increase rates of evapotranspiration and may reduce river discharge whereas very cold temperatures may freeze the ground, restrciting infiltration increasing surface runoff and the likelihood of higher river discharge.

Albedo effect

Ice reflects more solar radiation than water (because of the color, white) Therefore, even less solar energy will come to the Earth - that increases the amount of ice more- this causes more reflection - causing feedback cycle

Factors affecting river discharge and regime-Basin size, shape and relief- relief

In steep-sided upland river basins water reaches the channels much more quickly than in gently sloping lowland basin.

Links between the water and carbon cycles at local scales- desertification

Land use - Desertification shows 1. How water and carbon cycles are closely coupled. 2. How water cycle changes are linked with soil and vegetation loss 3. The interdependence of soil and vegetation health Desertification (eg. the Sahel, affected by climate change and land use) Reduced vegetation cover may lead to reduced carbon sequestration in biomass and also soil carbon. Less vegetation cover may reduce the remaining soil infiltration capacity; this means infiltration-excess runoff will take place when rain occurs, resulting in soil erosion and gullying Accelerated soil erosion will reduce carbon storage With less soil cover, ecosystem net primary productivity will fall further Causes Climatic factors: rising carbon emissions and rising temperatures causing cyclical drought Bringing lower and less reliable rainfall Land use" over grazing by cattle More wood biomass used for fuel and shelter by growing populations Over use of aquifers

Factors affecting river discharge and regime- Precipication- amount

Long periods of rainfall area frequent cause of flooding. The soil becomes saturated and infiltration is reduced - this generates large quantities of surface runoff causing rapid rises in river discharge.

What strategies are there to manage aquifers in order to tackle water deficits?

Managed recharge in California Managed recharge, is umbrella term for using various techniques to actively introduce excess surface water, including storm water, treated water and agricultural runoff, into aquifers. In 2014, California passed the first state-wdie legislation to ensure the careful management act, provides standards and assistance to lcoal water agencies, ad mandates that local systems establish Ground Water Sustainability Agencies to oversee improved monitoring and Sustainable management of ground water stores. The city of Roseville manages injection wells that force water into the ground The Coachella Valley diverts excess flows from the colorado River into recharge basincs to collect water and allow it to seep into the ground Farmers inFrensno county use a network of levees and irrigation gates to flood orchards, vineyards and vegetable and alfalfa fields with water and then allow the power of gravity to drive water back into depleted underground aquifers.

Loughor- lower

Marshland ( already moisturized ) ↑ Runoff (lands are steep as well), ↓ infiltration ↑ evapotranspiration ↑ interception ( less urbanised)

Extreme rainfall (hurricanes, typhoons) caused due to GHG- Alia hurricanes

May 20th 2009, Banglades/Sundeban 75mph more than 6 million people affected 330 died 8208 missing 500,000 homeless 95% cropland contaminated with salt 80% of fishing equipment destroyed/lost Total damage : 552.6 million

Methane feedback

Methane is stored in permafrost region (permanently frozen ground) a quarter of the Earth's surface is affected by continuous or sporadic permafrost, including tundra, polar and mountains Permafrost covers 23 million square killometres It formed during past glacial periods and has persisted through warmer interglacial periods, including the Holocere.

Methane issues

Methane traps 30 times more heat than carbon dioxide Methane as a large natural component from permafrost Soil decomposition accelerates? more greenhouse gas 205 gtc equivalant of Methane could be released due to melt of permafrost > 0.5 degree celcius extra warming by 2100 Outbreak of deadly anthrax in Siberia 20 people infected, Melting permafrost was again suspected, thawing out dead egetation and erupting in a blowout of highly flammable methane gas 14 craters setting fire to methane released from frozen lakes in both Siberia nad Alaska

Temperate grassland storage

Mid-latitude grasslands are found on the periphery of mid-latitude deserts, typically between 30 and 50 north of the equator, with only small pocket found south of the equator. The lee side of mountain systems which act as a barrier to westerly flowing moist air, thereby giving risk to a rain shadow. The global distribution comprises several extensive non-coastal regions North American prairies The Eurasian steppes South Africa veld landscape The South American pampas. The lack of rainfall is a major limiting factor preventing the growth of thick forest cover Instead, short perennial grasses dominate the landscape Thier narrow, upright stems reduce heat-gain in the hot summers, their roots trap moisture and nutrients below the ground. Two types are Turf grasses; with rhizomes (underground stems) from which new plants grow. These are associated with more humid parts of the biomes Bun grasses, without rhizomes, that produced by seed. These are associated with the drier parts of the biome. Physical factor Light: The Sun's rays are concentrated during Summer at these latitudes but are much weaker during winter months when they may be no more than 6 hours of daylight This results in marked seasonal variations, in plant growth and biomass carbon storage Temperature: the mean monthly temperature varies between 22 Summer and -5 in winter Temperate grassland at high altitude or closer to the coniferous forest boundary may experience an even more extreme temperature range Precipitation: low average annual rainfall of around 500 mm or below In much of biome, this is spread relatively evenly throughout the year However, there is a substantial build-up of winter temperate grasslands found at higher northern latitudes Animal biodiversity and biomass is relatively low Simple climate and vegetation zone No more than two or three species of large grazing mammals, such as Bison, occupy a typical temperate grassland However, below ground, the majority of temperate soils, support significant populations, and 1square metre may contain up to 500 earthworms As they consume organic matter and excrete waste, earthworm plays a key role in carbon cycle movement for temperate grassland. in total, 185 gtc is stored in temperate grassland biomass and soil Temperate grassland typically stores 2 to 10 tonnes of carbon per hectare above ground and double this amount is stored below ground as roots in most temperate grassland ecosystems, two-thrids of the root biomass is found in the top 30cm of the soil The soil carbon store (humus) averages around 100 to 200 tonnes of carbon per hectare Warm, humid conditions in outcome ensure rapid decomposition of dead grass matter and the quick release of co2 As a result, the litter store is small in this biome Exchange of carbon between the atmosphere, biosphere and soil vary greatly according to season In winter, the grasses die back to their roots and photosynthesis ceases Plants can continue to respire through their roots, however, especially once the soil beigns to warm in srping.

Feedback in and between carbon and water cycle

Most natural systems, unaffected by human activity exist in steady- state equilibrium( reaching dynamic equilibrium) Feed back helps us to model system dynamics over time

Drought in the state of California - USA- causes

Most of California is semi-arid. There is higher rainfall in the North. In the summer months, it usually experiences high temperatures and low rainfall as a high-pressure system over the Pacific ocean block moist air currents. Although the coastal ranges and Sierra Nevada mountain ranges generate orographic rainfall in areas east of the coastal ranges and East of the Sierra Nevadas. It is thought that the extreme conditions during the 2012 to 2016 drought were caused y a mass of warm water in the Pacific ocean that has drifted closer to the west coast of the USA close to California coast. The warm water formation, known as the blob has persisted in about the same location for over two years and is about a thousand miles across and 300 feet deep. La Nina likely kicked off the drought cycle in 2011 by creating a persistent high-pressure system just off of the west coast, close to California. The high-pressure system interfered with storm tracks and wind flow, causing storms that would usually have hit California to chart a different course of drench other locations with their much-needed precipitation. The high-pressure system created by La Nina also rerouted cold air away from this location over the Pacific, which prevented the atmosphere, contributing g to the blob. California relies upon the build-up of a snowpack in the winter to melt into runoff in the spring for the state's water supply Snow is more beneficial than rain for drought relief. The blob of warm water, heats the atmosphere above it, making rain more likely than snowfall. during the drought, California has had record-high temperatures adn reocrd low snowpack depths.

Different parts of the UK experiece slightly different regional climates

Northwest- cool summers, mild winters, heavy rain all year North East- cool summers, cold winters, steady rain all year South East- warm summers, mild winters, light rain all year, especially summer. South west- warm summers, mild winters, heavy rain all year especially winter. The variability of weather and climate in different regions of the British Isles is due to the different air masses that meet over the Isles. SW: warm and wet > frontal rainfall, relief rainfall SE: warm and dry > convectional, a little bit of relief NE: cold and wet > frontal rainfall, relief rainfall NW: cool and very wet> frontal rainfall, relief rainfall.

Variations in rainfall in the UK

On average, it rains one in three days in the Uk However, rain varies greatly from region to region it is generally wetter in the west than the east and wetter in the highland than the lowlands. The wettest place in Snowdonia in Wales (average annual totals exceeding 3000m of rain a year), followed by the highlands of Scotland, the Lake District , the Pennines, and the moors of South West England Parts of the east such as East Angila, receive less than 700mm a year. In most places in the UK, it will rain twice as much in winter months as in Summer months. Although in central and South East England, and parts of South East Scotland, July and August are often the wettest months of the year. In London and Birmingham it will thunder on average 15 days a year, compared to less than 10 days in the UK.

Formation of peat

Peat derives from high levels of partly decomposed plant matter such as sphagnum mosses, rushes sedges and bracken The plant remains are slowly compressed as more material is added each year Overtime, layer upon layer of dead matter accumulates until depths of 2~4m can be achieved Decomposition is prevented by the waterlogged environment which created oxygen-deficient anaerobic conditions This limits microbial decomposition of organic matter especially in upland sites where temperature more acidic (deters soil organisms) Peat has been accumulating for much of the Holocene (most had begun to form by around 7000 years ago) There are recognisable animal remains ( a 2000 year old human body in Wilmslow, Cheshire)

Peat

Peat is a thick layer of black or dark brown sticky and wet soil material Peatlands such as the poorly drained fenladns in East Angila Peat

How has the damage and removal of peatland environments contributed to increase in atmosphere carbon

Peatland Thousands of years to form 2 billion tonnes of Co2 released each year due to peat damage More than 100,000 hectares of peatland is destroyed for palm oil/agricultural plantation A million tonnes of carbon is released into the atmosphere Tropical peatland forest locks up to 5 times more carbon than tropical forest and accounts for a third of the total carbon reserves. 85% of greenhouse gasses is from landuse, 27% due to peat fine 3300 tone per hactare stored in the peat half would be released because of palm oil conversion Carbon peatland (verty acidic/ fewer nutrients) Malaysia lost 357,000 hactare 45.3% of its peat land between 2000 and 2010 Indonesia lost 2.1999 million hactare 17.3% of its peatland between 2000 and 2010

Damage to peatland- Forestry

Peatlands drained by the Forestry commission will begin to emit Co2, and loose some soil carbon via leaching and erosion, but this may be offset over time by the co2 captured by the growing of tress in its place.

Factors affecting river discharge and regime- Rock type

Permeable rocks allow water to pass through them. Rocks uch as sandstone and chalk are porous and allow water to fill the many pores in the rock e.g carbonifurous limestone allows water to enter the bedding planes and joints These rock types have few surface steams due to high infiltration rates and limited surface runoff Rocks such as granite are impermeable they do not allow water to pass through them so surface runoff is increased and there are more surface streams.

Consequences of ocean acidification

Ph> has lowered (8.1 global average) logarithmic base Ocean acidity could increase 100~150% by 2100 Oyster industry affected especially pacific North Sea increase in hydrogen ion, reduction in carbonate ion Growth of coral reef colony reduced by 13% since 1990 Co2 level went up from 280 ppm to 387 ppm, difficult to build shell: decline in calcification is unprecedented in the past 400 years Acidity of Sea increased by 30% since industrial revolution increase in acidity means it is extremely difficult for animals to adopt Brittle star produces less larvae Tiny algae bottom of food web, preditor such as salmon cannot survive Young clownfish lose ability to smell home Number of aragonite will fall from 60% to 80% by 2095, in north hemisphere. Washington Acidity hot spot (along with antarctic+arctic) Big hit on shell fish and oyster populations Impact on fishery industry (250 million/ year) total impact of 300 million/ year

The Boscatle flood in 2004- physical causes

Physical causes 1. Location of the village, within the Valency Valley. The valency is normally a quiet stream, which follows a very steep course down into the valley from the hills around. Its steepness accelerated the rainwater falling on the hills above the valley greatly as it travelled down to the valley floor where Boscastle stands. The shape of the valley concentrated rainwater from the surrounding area into a relatively narrow space descending towards the valley bottom. Not only did this cause an increase in runoff speed but also an increase in discharge volume, which caused floods. Weather. - The entire south-west of England had been battered with stormy weather over the days leading up to the flood on the 16th of August, the ground was saturated The 16th was a very hot day, with the clear sky in the morning and high temperature for much of the day. The combination of high localised temperatures and the abundance of unabsorbed surface water, coupled with moist winds off the sea and the effects of the local relief (Bodmin Moor) caused a great deal of moist, warm air to travel upwards quickly. In few hours, a massive 5 inches of rain had fallen in Boscastle alone. The sheer volume of water in such a small space at once caused the Valency to burst its banks and cause the exceptional level of damage in the village.

Water carbon links > precipitation and carbon store

Precipitation on litter helps decomposition as it brings micro-organisms The overland flow picks up litter and transports to streams, and eroded land loses soil, less carbon store In the long term, precipitation which forms humus in the forest can help growing vegetation and it increases interception/ evapotranspiration/ infiltration whereas it reduces runoff

Tropcal rain forests

Rely on certain physical factors to allow plant growth and carbon storage Rainforest net primary productivity averages around 2500 grams per square metre per year Biomass can be as much as 700 tonnes per hectare Light: the sun's rays are concentrated at this latitude with little seasonal variation This result in all year growth and carbon sequestration Temperatur: high average annual temperatures between 25 and 30 with only small seasonal variation precipitation: the Sun's heating causes moist air to rise, cause heavy rainfall. A high average annual total of 2~3000 mm with no dry season High and constant rain combined with warm temperature provides optimum condition for terrestrial plant growth and biomass carbon storage. Five layers 1. a field layer 2. shrub layer 3. under canopy(30) 4. a continuous canopy(50) Plnats are evergreen, have large leaves, maximise their rate of photosynthesis transpiration and growth Carbon storage of animals is relatively high large number of habitats, provided for animals More than two thirds of the world's plant species are found within rainforests In total 550 gtc is stored in tropical rainforest biomass and soil Large froest trees typically store 180 tonnes of carbon per hectare in their roots. The soil carbon store average around 100 tonnes per hectare Compared with other forest, exchanges of carbon between the atmosphere, biosphere and soil are rapid > warm, humid conditions ensure rapid decomposition of dead organic matter and the quick release of CO2. As a result the litter store is proportionally small in this biomes. Heavy rainfall means that soils are leached and only retain limited amounts (proportionally) of organic carbon in the form of humus.

The energy budget

Rising GMST is believed to be a product primarily of increases in the atmospheric carbon store which have impacted on the Earth's energy budget The energy budget is the state of balance between incoming solar radiation received by the atmosphere and the Earth, and the re-radiated heat or reflected energy Approximately 31% is reduced by clouds, aerosols, and gases in the atmosphere and the land surface The remaining 69% is absorbed; almost 50% is absorbed at the Earth's surface, especially the oceanns 69% of this surface absorption is re-radiated as longwave radiation This trapping of longsave radiation in the atmosphere is what gives a life-supporting average temperatrue of 15, the natural greenhous effect. Wihtout this process, the Earth would be -18 and too cold for life to have evolved. Increasing carbon emissions mean that more heat is being radiated back towards the ground surface The nergy budget is changing with more heat being retained, resulting in a warmer, and more energetic climate system.

Ganges river case study - River regime, Moonson climate

River ganges river regime - A low flow dry season from Jan to May and a wet season from July to Nov Monsoon climate 1. Rainy season, Jun to Sep the rains are brought by the south-west monsoon in June 2. Cold dry season, Oct to Jan The winter conditions are dominated by the northeast monsoon and temperatures are lower 3. Hot dry season, Feb to May This season occurs all over India In the interior, especially the north, temperatures are very high. This season is not entirely rainless as there are conventional thunderstorms in places and tropical cyclones affect the bay of Bengal coast

River discharge (with GHG increase)

SInce the 1980s, river flooding has increased in size and duration during winter lower river discharges may become more common in southern England as a result of less frontal rainfall insummer Although high intensity convectional rain can be expected, sometimes in summer, which can lead to infiltration-excess overland flow River discharge will quickly return to a low level after a brief flashy hydrograph response to the rianfall.

Cryosphere feedback negatvie

Sea lce melts and darker ocean begin to absorb solar radiation> increased evaporation from the warmer ocean> more loss cloud cover> increased albedo of atmosphere> ocean temperature fall slightly> sea begins to reform ice> higher albedo> the solar radiation reflected> ocean temperature falls slightly... There will always be both (which one dominates which?)

Prolonged and Intense stroms in UK 2015-2016- negative impacts

Several thousands homes and businesses were inundated with floodwater in Cumbria, with parts of Lancashire, Northumberland and Southern Scotland also affected. Carlisle was worst hit by severe flooding from the River Eden, but many other area affected as well that tens of thousands of homes across Cumbria and Lancashire were without power for several days. A number of bridges were swept away by floodwater including Pooley bridge, Ullswater, built in 1764. There were two fatalities and many roads and rail links were cut, including the west coast main line. Schools and hospitals were closed in the flood affected areas.

Sea level rise- the Sunderbans

Spans the mouth of the Ganges delta from eastern India to Bangladesh Demography 2.5 million people have no where to go The Sunderban: more than 4 million are threatened by rising waters/ number o cyclones Young people left to find work in Kolkata, old people left behind The habitat of the Bengal Tiger has been put at risk, home to 500 tigers in the 1960s to 200 now Economy Rising sea levels are destroying livelihoods as salt water contaminates rice fields, rendering them unusable for years (3 years) Society Local inhabitants are threatened by flooding 40 km area are expected to be lost Gharamara: 600 families have been displaced 20,000 refugees swamping the original inhabitants of Sagar putting pressure on resources People are becoming dependent on aid Villagers from Dayapur villege wait for water relief to be supplied by the Indian government Collect water from a pump by a flooded/polluted rice field, increasing temperatures, increase in diseases both from mosquitos and water borne illnesses such as Cholera, typhoid Communications The hamlet on Ghoramara can only be reached by a narrow path along a mud dyke braced against the swell of the sea People have to travel 3km muddy path

Elements of Carbon cycle

Stores are the amount of carbon held in particular parts of the global system and have a residence time Flows are exchanges or transfers between these stores and have a rate of flow (measured as units of mass per unit time) Inputs and Outputs are flows into particular local systems or cycles. Processes are the physical mechanisms that drive the inputs, flows and outputs. For example, photosynthesis is a process of the carban cycle. The concept of mass balance can also be applied. This means that at a global scale The total amount f Carbon stays the same even through amounts inparticular stores may vary over differing timescales.

Photosythesis

Take place in all plants varies between day and night/ seasons/climatic zones NPP( net primary productivity) which is new organic matter created per unit area per unit time CO2 + H2O+ sunlight = glucose and oxygen aka Carban fixation

The implication on System feedback for life on Earth

The GMST rise prediction for a high emission varies from 3 to 5 degree Reflects uncertainty around the stregth and timing of possible positive feedback loops Potential disappearance of large parts of the croyshere water security problem The sustainability of these growing settlements in threatened by a new lack of water security for the south west Asian region as a whole Many major rivers are fed by seasonal meltwater from major glaciers in the region, notably the Himalayn plateau Every summer, Ice melts and feeds asia's largest rivers fresh snowfall each winter replenishes the glacier, meaning that over time the meltwater cycle is sustainble However, climate change system feedback threatens to permanently reduce the size of glacial ice stores in the region Although this will increase meltwater in the shortrun in the long term it could lead to dangerous water shortages because there will be very little ice left to melt.

Why is excessive runoff generated in specific climate zones?- Case study monsoon rainfall in Bangladesh, June 2017)- winter monsoon

The Indian oceans winter monsoon, which lasts from October to April, is less well-known. - The dry winter monsoon blows from the northeast - These winds start in the air above Mongolia and North Western China - Winter monsoons are less powerful than Summer monsoons in Southeast Asia, in part because the Himalaya muntains prevent much of the wind and moisture of the monsoons from reaching the coast. - The himalayas also prevent much of the cool air from reaching places like Southern india and Sri Lanka, keeping the warm air all year. - winter monsoons are sometimes associated with droughts.

Montgomeryshire Wildlife trust

The Pumluman project (to revive the ecology and econoy of the Welsh uplands) A pioneering experiment in an area of Mid Wales (250 farms, 15,000 inhabitants, and catchments for five rivers incuding the river Severn and Wye) Aim to solve landuse problems Change 40000 hectares of Mid Walse is managed for products and services (by conservation, farming, forestry, tourism) Supported by Welsh Assembly Government, the Countryside Council for Walse)

Residence time

The amount of time water spends in each store changes from store to store which can have a significant impact on the amount of water moving through the cycle at various timescales ( known as the residence time)

feedback system threshold

The concept of a system threshold can be important This is a critical limit or level that must not be crossed if accelerated and potentially irreversible changes are to be avoided, making it much less easy for the previous equilibrium state to be restored. Global temperature rise in access of 2 degrees will lead to widespread and irreversible changes in the global carbon cycle because of positive feedback processes At a local level , the overgrazing of vegetation in areas at risk of desertification could cross a threshold e.g. too much vegetation lost Widespread soil erosion Vegetation cannot easily re-colonise Irreversible loss of both vegetation and soil store means that local water and carbon cycles will be permanently changed.

Peat extraction and drainage

The drainage, burning, cultivation and cutting of peatlands release 2 billion tonnes of co2 each year 10% of total global carbon emissions In the UK, 20% of peatlands are not degraded and remain in a pristine state (1% of England) Rates of Carbon Sequestration in degraded peatlands are reduced and may even become sources of carbon emissions instead Peat have been directly affected by the practice of cutting peat to burn as fuel or industrial use Fuel source in rural area, traditionally In Scotland and Ireland, peat is harvested on an industrial scale for use in power stations Peat taken from raised bogs in lowland area is commercially extracted by the horicultural industry and sold as nutrient rich soil and compost in garden centres Islay, Scotland, peat is burned as part of the whisky-making process. (Lagavulin and Laphroaig distilleries) Smoked meat and fish

The earth's climate change

The earth's climate is currently warming and changing in 2015, the global mean surface temperature reached a new record high of +0.87 relative to the 1950~80 average The ten warmest years since 1880 have all been since 1998

River channel discharge

The entry of runoff and precipitation into rivers and its flow to the ocean.

Meterorological causes of droughts- UK summer drought 1976- Impacts of the drought

The hot, dry weather affected domestic water supplies leading to widespread water rationing The national water council took out full page ads in newspaper on how to beat the dorught advising steps such as only taking a both if absolutely neccessary and using no more than fiver inches of water. As crops failed and food prices subsequently increased, a Drought Act was passed by the government, a Miister of Drought appointed and plans to tanker water in from abroad were discussed. Heatlth and Forest fires broke out in parts of Southern Engalnd with 50,000 trees being dstroyed in Dorset alone.

Size of global water stores

The hydrological cycle is driven by solar energy which provides energy for evaporation and gravitational/potential energy ( the downward movement of precipitation) The size of water stores can differe greatly depending on the type of store which > can change dramatically over different timescales depending on climatic factors.

Q. Explain what is menat by the concept of the hydrological cycle

The hydrological cycle on a local scale summarises the characteristics of a drainage basin. It is an open system with inputs of precipitation and energy from the sun; flows and stores either on the surface, through the ground or on vegetation, and into the sea or evapotranspiration. On a global scale the hydrological cycle is a closed system of only flows and stores.

The Boscatle flood in 2004- human causes

The lack of any flood control system, in the form of either raised banks around the river channels or emergency drainage ditches to catch overflowed water. Had these measures have been in place no doubt the flood waters would have been slowed and delayed giving people more time to evacuate. The sewer and drainage systems were old and had a small capacity The surge of water borke the system, preventing any controlled drainage from occurring in the villege. the flood water simply took the route overland, causing more dmaage. Structure obstructing the river course increased the spread of the floodwater. The bridge in the centre of the villege, under which caurs and vegetation became stuck As the flow of water was partially blocked, some water had to flow around the bridge, flooding properties further from the river channel than perhabs would have ben had the obstruction not occurred. However, the flashflood was a freak event, difficult to place blame for the human conditions which intensified the damage which it caused, as no one could have predicted the event in the first place Lag time is short (5 hours) water flushes in quickly and in massive volume, flooding becomes more powerful.

Stategies for the restroation of peatlands

The majority of England's peatlands are currently sources of greenhouses gases Only 20% of undamaged peatland continue to function as carbon sinks cultivated and temporary grass: 22.4 net loss Improved grassland :8.7 net loss Rotational Burnt: 2.6 net loss Afforested: 2.5 net loss Bare peat : 0.1 net loss Overgrazed: 0.1 net loss Undamaged : 4.1 net storage Peatland is important for maintaining biodiversity Peatland restoration help meet the carbon reduction target > local and national governments may be able to offset greenhouse gas emissions produced by economic activity

Carbon processes and pathways : flow from the atmosphere to the oceans - physical pump

The ocean takes up dioxide by carbon cycle pump mechanisms The physical (inorganic) pump involves the movement of carbon dioxide from the atmosphere to the ocean by a process called diffusion CO2 dissolved on the surface of the ocean can be transferred to the deep ocean in areas where cold dense surface waters sink. This downwelling carries molecules to great depths where they may remain for centuries This level of CO2 diffusion also determines the acidity of the oceans It can be released by volcanic activities on the seabed, breakout.

Biomes

The proportion isze of the plant, animal, litter and soil stores may vary greatly between biomes and may also change within a particular eco system according to the season Green plants : 20% of the caron in the Earth's biosphere Although exposed part of the plant is the most visible, the below-ground biomass (the root system) must be considered In grasslands, the majority of the biomass consists of root systems. Animals: plays a small role in carbon cycle Because, the biomass of animals in a biome is much smaller than that of palnts and because of the inefficient energy transfer that takes place between differnt trophic levels. Litter, this is defined as fresh, undecomposed and easily recognisable plant debris This can include leaves, pine needles and twigs. leaf tissues account for about 70% of litter in forest Soil: Humus is a black substance that remains in the soil after most of the organic litter has decomposed It gets dispersed throughout the soil by earthwarms and other organisms.

Factors affecting river discharge and regime- Precipitation- type

The two main types of precipitation are snow and rainfall - The heavy snow is intercepted and tored. - Over a long period, this may lead to a fall in river levels. When temperatures rise and melting occurs the water is released. - This may generate large quantities of surface runoff, which reach the river channel quickly, especially if the ground remains frozen restricting infiltration. - Rainfall is also intercepted but may infiltrate quickly if the soil is unsaturated. The rate at which it reaches the river channel depends on interception, infiltration and overland flow.

Restoration effects

The re-establishment of plant cover dominated by peatland species including Sphagnum mosses The re-wetting of drained peatlands by raising and stabilising the local water table CO2 emissions from the decomposition of the peat are reduced immediately after a previously drained peatland is re-wetted and anaerobic conditions have returned. New peat formation will occur, with ongoing sequestration of atmospheric carbon The environment will be restored as a carbon sink rather than a source of carbon Eg. peatlands of the southern Pennies in Yorkshire These highly degraded peatlands were extensively drained in the past and have been severely eroded by overflow and gullying block erosional gullies with store dams to help raise the water table and retain moisture in the peatlands, thereby restoring anaerobic conditions Reintroduce wetland species, for example by re-seeding of the landscape to restore its original vegetation cover including cottongrass and Sphagnum Moss re-vegetated surfaces are much less prone to erosion In Scotland, large areas of peatland that were drained for forestry are being restored to their natural state Drainage have been blocked, and trees removed from the landscape These techniques appear effective in reducing carbon loss from the proof

Factors affecting river discharge and regime- land use- urbanisation

The removal of vegetation and its replacement by concrete and tarmac surfaces reduces infiltration to zero but the drains and gutters transport the water more quickly to river channels increasing discharge and the flood risk 30% evapotranspiration 55% runoff 15% infiltration.

Meterorological causes of droughts- UK summer drought 1976

The spell of hot weather, from mid June to the end of August included 15 consecutive days where a maximum temperatur of 32 or more was recorded somewhere in the UK. A recird breaking drought The highest temperature recorded was 35.6 in Southampton on the 28th June 1976. Whilst 35.9 recorded in Cheltenhan was the highest in July temeprature on record. Below average rainfall was notable from May 1975 to August 1976 resulting in one of the most significant droughts of UK climate records. This made the Summer 1976 the 2nd driest summer on record behin 1995 During the 1976 heatwave parts of the UK went without rain for 45 days. There was below average rainfall during winter 1975 so ground water and surface water storage was lower than average.

the 41,000 years tilt- glacials interglacials

The tile of the earth's axis, which is responsible for our changing seasons, changes up to 3 degrees (from 21.8 to 24.4 and back again with a cycle of 41,000 years) - this changes the seasonality of the Earth's climate - the smaller the tile, the smaller is the difference between summer and winter. - A smaller tilt promotes the growth of Ice - when tilt increases, summers will become hotter and winters colder, leading to conditions favoring interglacials. Big tilt= increased seasonality Small tilt= decreased seasonality

Ganges river case study - Human factors (abstraction, dams) affect the Ganges

The use of dams for irrigation has major impacts downstream. - India and Bangladesh have quarrelled over rights to water from the Ganges for over two decades. - India started taking water from the Farakka dam since 1975 Aim was to 1. Irrigate farmlands in West Bengal, 2. Improving shipping access to the part of Calcutta by flushing silt out to sea. - Bangladesh faced a huge drop in discharges as the dam was 18km from its border (from 75000 to 15000 cubic feet per sec from 1975 to 1998) - The silt which has built up behind the dam has forced the River Ganges to alter its course, dam shifts the river almost eastward over 30 years, eroding a complete village. - The Ganges basin takes up 0.12% of the world's land mass, but is home to 10% of world's population who need water supplies - Therefore, extraction of water is high which lowers the discharge of the river, especially in urban areas where water is used for domestic supply, industrial use and irrigation in over 29 cities. - Population density is 800 people per km2

Percolation

The vertical movement of water, under the pull of gravity, from the soil into permeable rocks

Seasonal rainfall pattern change due to GHG

There could be an increased frequency of frontal rainfall in winterl and a greater probability of summer drought because of reduced frontal rainfall Summer: increased evaporation from warm ocean> Raised temperatures reudce condensation > less rain generally but increased turblence increases storm rain> increased rain as water vapour cools and condenses Winter: increased evaporation from warm ocean> cool enough for condensation increased rainfall> increased rainfall reduced snowfall.

Raised bogs

These received their surface water only from precipitation but often start off as fens Once fen peat has built up, rainwater begins to dominate the nutrient supply and bog mosses begin to lay down a dome of wet acidic peat Rare plants (bog rosemarry, cranberry) Invertebrates( heath butterfly, bog bush cricket and bog pill beetle)

Carbon Process and Pathways: slow flows between the land and oceans

This is often referred to as the slow carbon cycle. The cycling of carbon between bedrock stores on the land and the oceans occurs through the processes of weathering, erosion and deposition over very long time scales (millions of years) and at a continental scale. Firstly, weathering of land-based rocks takes place, including chemical weathering which involves rainwater containing dissolved CO2 forming a weak carbonic acid. Carbonation is the primary processes which affect carbonate rocks such as Chalk and Carboniferous Limestone. These are made of dominantly Calcium Carbonate which react with the carbonic Acid to produce Calcium Bicarbonate (soluble). Globally some 0.3 billion tonnes of carbon are transferred from rocks to the atmosphere and oceans each year by chemical weathering. This removal of carbon in solution from the land is an important way in which the carbon and water cycles are linked Calcium Bicarbonate can be transferred by overland flow, throughflow or ground flow into rivers where it becomes part of the solute load (dissolved material carried in solution, an important transfer mechanism) Over time, large amount of carbon has been removed in solution from limestone areas of the UK such as the cliffs at Llandudno : Carbonation weathering takes place when rainwater collects in pools on the surface of exposed rock ( e.g. limestone pavements in Malham, Yorkshire) and in Chalk regions such as England's South Downs, the slow movement of groundwater dissolves the rock it is moving through, and eventually transfers calcium bicarbonate in solution into river system and ultimately the ocean. Once in the ocean, carbonate is used by marine organisms to create shells. When they die, these organisms' carbonate shells are deposited as carbonate-rich sediments on the ocean floor Here they are eventually Lithified (turned into rock) This part of the carbon cycle can lock up carbon for millions of years. It is estimated that the oceanic sedimentary layer may store up to 100 GtC.

Factors affecting river discharge and regime- land use- vegetation

Trees and plants help reduce the amount and rate at which water enters a river channel by interception, root uptake and evapotranspiration - it is estimated that the tropical rainforests may intercept up to 80% of rainfall whereas arable land may intercept only 10%. 40% evapotranspiration 10% runoff 50% infiltration

Residence time Formula

Volume of the reservoir or store/ transfer rate (in or out)

What are water deficits within the water cycle?

Water is a fundamental human need for food and energy. When there is not enough water within the water cycle for human needs those areas are in water deficit. An important cause of water deficits is droughts. Droughts are on extended period of usually dry weather when there is not enough rainfall. Period of drought can often be hard to define because a drought means different things in different regions. A drought in the UK means a period at least 15 consecutive days or more where there is less than 0.2mm of rainfall. Compared to Libya in the Sahel region, a drought is usually only recognised after two years without any measurable rainfall. In the long term, drought in the UK is also defined as a 50% of deficit over three months, or a 15 percent shortfall over two years. The term "drought" can have different meanings to different people, depending on how a water deficiency affects them. Droughts have been classified into different types - Meteorological drought = lack of precipitation - agricultural drought- lack of soil moisture - hydrological drought- reduced stemflow or ground water levels.

What are the human cuases of water cycle deficit?- economic factors- Industrial demands for water

Water is used in manufacturing of microelectronics, medicines palnes and military equipment, as well as the refining of oil and the making of movies in Hollywood. Many companies have landscaped grounds with lakes and gardens watered by sprinklers. Business executives expect facilities like golf courses.

Infiltration

Water may soak into the soil pores- a process called infiltration - the maximum rate at which this can take place is called the infiltration capacity - At the start of a rainstorm, infiltration is often quite high because the soil is dry, but the rates go down as pore spaces reduce constantly. - clay and silt have much lower infiltration rates than sand and gravel due to differing size of pore spaces in the soil - The infiltration rate is affected by the existing moisture in the soil, soil porosity and structure, the nature of the soil surface and the amount and type of vegetation cover. - In urban areas, many surfaces are impermeable tarmac and concrete, no infiltration can occur. - when the infiltration rate is exceeded, then the surplus water flows over the ground surface as overland flow.

Extreme rainfall (hurricanes, typhoons) caused due to GHG- Phailin

Western Asia and India October 12th 2013, India Cat 3 - 125 mph winds Strongest cyclone in 14 years 250mm of rain in 2 days 12ft storm surge 21 million people affected 44 dead 800,000 homeless 5000km2 of paddy crops destroyed losing 320 million 1000 siberian migratory birds dead total cost 1.35 billion

Carbon stores within Biomes( ecosystem in a global scale)

When human activity is taken into account, the total amount of carbon stored in the terrestrial biosphere is estimated to be 3000 GtC. This storage is spread unevenly among the different terrestrial biomes. Forests are significant carbon stores; they make up more than half of all terrestrial ecosystem storage Carbon is stored primarily in the biomass of the trees, but a thick litter layer on the forest floor can also store significant amounts Boreal (coniferous) forests store more carbon than tropical rainforests globally because it is distributed across a greater area, including much Northern Russia and North America. The biomass of tropical rainforests ( the weight of organic matter per unit area) is greater than that of boreal forests but it does not cover as great a land area. In order to grow and create new organic matter, plants require a variety of nutrients Some are provided by the photosynthesis process while others are extracted from the soil by plant roots Carbon is an essential plant macronutrient and makes up approximately 44% of dry weight of plant biomass. This is because it is a major component of all organic molecules. By comparison, nutrients such as potassium and calcium may account to less than 1% of dry weight. Some carbon is eventually returned to the atmosphere by volcanism CO2 is released from the melted rocks when subduction occurs at plate boundaries and is then released through fissures and during eruptions. One of the earth's largest carbon store is in the Himalayas in calcium carbonate from the destruction of the ocean once found between the Eurasian and Indian landmasses Folded upwards long ago by mountain-building processes this carbon is now being actively weathered, eroded and transported back into the ocean. Water cycle processes including monsoon rainfall and runoff play an important role in this processes.

Drought in the state of California - USA - The impacts of drought

While drought is common in California, but this drought was particularly brutal. California gets its water from 3 main sources snowpack water stored in reservoirs water pumped from underground aquifers During the drought, the stakes were high for California. The drought threatened the water supplies of the UA's most populous state with 38million residents. The drought threatened jobs and economic growth in its 44.7 billion a year agricultural industry, which generates more than 100 billion in related economic activity. The drought threatened US food supplies with California producing nearly half of all US-grown fruits, nuts, vegetables and dairy products. Because California farms depend heavily on irrigation to sustain production during the dry season, drought constitutes a dire threat to the state's economy. In 2015, hafl a million acres of farmland were fallowed in 2015, leaving thousands of agricultural workers jobless ( 2.7 billion and 10,000 seasonal job) more than a thousand families saw their drinking water wells go dry. Many more were forced to ration water, either because thier well production slowed down, or because a local agency imposed rationing.

Damage to peatland- burning

Widespread land management practice in upland areas for the management of game, such as Grouse. Burning the surface vegetation encourages new growth of young ehather with Grouse feed on, but can damage the wet Sphagnum mosses that create peat. Too much burning can remove the vegetation all together. Exposing the peat below, which can lead to subsequent rapid and widespread erosion of the peat during heavy rain

How might global seasonal chage influence the amount of water in certain stores?

Winter 1. increased precipitation as snowfall > increased ice accumulation 2. less volume of liquid store 3. less volume of transfers through system ( evapotranspiration, interception, infiltration, runoff) 4. slowing of cycling > basically the water( ice) kept in glaciers for a long time. Summer 1. Increased melt and evaporation from ablation zone = decreased volume of ice 2. increased volume of store (in the soil, puddle ( surface of the land), vegetation) 3. increased volume of transfers through the system. 4. spending of cycling However, over time the average rate of glaciers makes the dynamic equilibrium ( the sh&transfer and vice versa) Climate change such as global warming may increase the amount of ablation than accumultaion which may cause more trasnfer and the speeding rate.

A Drainage basin

a drainage basin is an area of land drained by a river and its tributaries. An imaginary line called the watershed delimits or separates one drainage basin from another. The watershed usually follows a ridge of high land; any water falling on the other side of the ridge flows into a nadjacent drainage basin.

Stemflow

a slower movement of the water trickling down stems and branches

A tributary

a tributary is a stream or small river flowing into a main river

Positive feeback loops

are knock on effects in natural systems that act to accelerate and amplify any changes that have already started to occur after a disruption has taken place When one element of a system changes, it upsets the overall equilibrium, thereby leading to changes in other elements which reinforce what is happenidng Positive feedback Global temperature rise Warms the ocean Increased oceanic temperatures Warm water less able to dissolve gas Dissolved CO2 released by warmer oceans CO2 back into the atmosphere More CO2 in the atmosphere More CO2 to act as a greenhouse gas There is a concern that positive feedback effects associated with human emissions of carbon dioxide will be far greater than negative feedback effects in coming decades Risk of a high rise in GMST of 4 to 6 occuring by 2100

Factors affecting river discharge and regime-Basin size, shape and relief- shape

circular river basins tend to have a shorter lag period and higher peak flows than elongated river basin

Temporal variations- seasonal fluctuations

eg_ a distinct wet and dry season in countries with a Mediterranean or Monsoon climate and where glaciers feed streams. -Even in Britain, there is usually a marked winter maximum of river discharge and a summer minimum reflecting lower precipitation totals and high rates of evapotranspiration in the summer - Short-term fluctuations of channel discharge are related to individual rainstorms or to snow melt.

Evaporation

evaporation is the direct loss of water from the ground or from water on planet surfaces It is greatest when temparatures are high and winds are strong

Respiration

glucous+oxygen= water vapour and CO2 Done by all living organisms, reversal of photosynthesis it varies like photosynthesis

Precipitation passing routes in urban area

gutter and drainpipes which flows much more efficiently than in nature.

What are the human cuases of water cycle deficit?

in 2005, California used 40.2 million acre feet of water. 78% of water was used by the agricultural sector. 22% was used by urban user.

Sea level rise

in the future, a warmer climate is predicted to bring a positive eustatic sea level change for two reasons. Thermal expansion of the oceans and worldwide glacial melting are projected to bring a series of eustatic sea level rise. A total global average sea level rise of approximately 3mm/year In total, global sea level has risen by 200mm since 1900 and the IPCC projects further world sea level rise of 200~820mm by 2100 Significant glacier and permafrost meltwater runoff will produce another metre of sea level rise by around 2200. Without any action to cut emissions, the complete loss of the greenland and antarctic ice sheets would result ultimately in a eustatic rise of nearly 70m

The river regime

is the annual pattern of discharge by a river responding to the region's climate - The average regime is shown by the mean daily or the mean monthly discharge figures. - It is primarily determined by climate e.g) the amount and distribution of rainfall together with the rates of evapotranspiration and snow melt

Condensation

is the process by which water vapour in the air is changed into liquid water It is crucial to water cycle because it is responsible for the formation of clouds > may produce precipitation which is the primary route for water to return to the Earth's surface with the water cycle. Water moluclues become organised in a less random structure - heat is released into the atmosphere as a result.

River discharge

is the volume or flow of water passing a gauging station in a river at a particular time River discharge is therefore the amount of water originating from precipitation that reaches the channel by direct precipitation, overland flow, throughflow and groundwater flow.

Negative feedback

occurs when a system adjusts itself in ways that lessen or cancel the effect of a initial disruption that has interfered with the system's normal operation The disruption to the system triggers changes in other system elements which act in the opposite direction to the initial change As a result, equilibrium or balance is restored e.g. Negative feedback Start: increased use of fossil fuels Increased co2 Global temperature increase More plant growth Increased take up more co2 by plants Reduces atmospheric co2 reduced Co2 has a dampening effect and reduces global temperatures.

Actual evapotranspiration

on average, the cooler, damper climate means that the amount of water available for evapotranspiration is greater than the amount that takes place, called actual evapotranspiration. Amount of evapotranspiration is much higher because of the greater availablity of moisture.

Damage to peatland- pollution

peatlands in Yorkshire have been subjected to decades of pollution from both Manchester and Sheffield This has led to widespread reduction in peat-forming plant species, amking the peatlands more vulnerable to erosion

The wildlife trust

plan to restore 4% of the UK's landmass to improve water quality, alleviate flooding, aid carbon storage and help wildlife. A million hectare challenge map is being prepared to set an ambitious target for restoring peatlands. Pealtands cover 12% of the UK and their restoration has never been a more pressing issue- 80% are in a poor condition because they have been drained of water or damaged by extraction The peatland code will encourage the private setor/businesses to invest in restoring this precious resource Restoration is vital because of peatlands 1. Store carbon- over three billion tonnes of carbon stored, they could remove an additional 3 million tonnes/year 2. Both store and clean water, as well as help, reduce flooding- there is huge economic value in improved water quality and flood alleviation 3.are fantastic landscapes for wildlife-rich habitats that are home to subtle and unique wild plants and animals, and fabulous wild places for people to enjoy

Potential evapotranspiration

potential evapotranspiration is the amount of water loss that would take place with unlimited water transpiration rates are high but the lack of rainfall and limited vegetation cover means the actual evapotranspiration is low i.g the Med, middle east

Precipitation

precipitation is all of the water that reaches the ground surface from the atmosphere. Mainly rain and snow some precipitation may fall directly into the streams and rivers; some may fall onto the land surface or be intercepted by vegetation- variety of routes to the streams, which run into a single stream to the basin outlet.

Flows and transfers - runoff

runoff is all the water enters a stream or river and leaves the basin as stream or river discharge

Carbon processes and pathways : flow from the atmosphere to the oceans - biological pump

the biological pump is driven by ocean phytoplankton absorbing carbon dioxide through photosynthesis These phytoplankton form the bottom of the ocean where sunlight is available for photosynthesis The phytoplankton are then consumed by other marine life and the carbon is transferred along the food chain by bigger and bigger fish and marine animals as they consume each other Organic Carbon may eventually be transferred to the ocean floor (this is known as the carbonate pump)

Ground water flow

the lateral movement of ground water through permeable rocks

Throughfall

the precipitation falls through spaces in the tree canopy and passes quickly to the ground

Factors affecting river discharge and regime-Basin size, shape and relief- size

the time it takes between the water falling on to the ground and reaching the river channel is called the lag period /lag time - in a large river basin, the water has much further to travel before entering the main channel giving a long lag period. - in a smaller basin, the water is likely to reach the channel faster giving shorter lag period between the water reaching the ground and entering the channel.

Factors affecting river discharge and regime- soil type

the type of soil controls the rate of infiltration, the amount of soil moisture storage and the rate of throughflow High rates are associated with sandy soils with large pore spaces whereas clays with small pore spaces have reduced rates of infiltration and throughflow encouraging surface runoff and the risk of flooding.

Spatial variation- tropical rainforest area ( equatorial climate)

there are great differences in the river regimes for different regions due to the interplay of a variety of factors but especially climate and vegetation - there is considerable river discharge - annual rainfall of 2000mm - river discharge is high although a proportion is lost by high rates of evapotranspiration resulting from high year-round temperature (above 28) and the large amount of vegetation in the rainforest

Transpiration

transpiration is the loss of water through tiny pores called stomata on leaf surfaces The effect of transpiration depends on the time of the year, the type and amount of vegetation, the availability of moisture and the length of growing season.

Discharge formulae

velocity (m/sec) x cross sectional area (M^2)

Carbon Cycle

what is the Carbon cycle? Cardon is ubiquitous Carbon based molecules are integral to all living creatures. Carbon Dioxide and Methane, another atmospheric gas containing Carbon, are present in the air we breathe. Carbon exists in a dissolved form in water, and is present in limestone, fossil foels, ocean sediments and soils. Carbon has become important politically, CO2 plays in anthropogenic climate change. Like water ,carbon is continually cycled at the global scale, and local stores and flows of carbon can be viewed as subsystems which belong to the bigger picture of global carbon storage.

Convectional rainfall

when the land becomes hot, it heats the air above it. This air expands and rises As it rises colling and condensation take place, and if it continues to rise, rain will fall. This type of rainfall is common in tropical areas and is quite common in the UK during Summer especially in the South East. 1. The earth's hot surface heats the air above it. 2. The heated air expands and coool condensation takes place. 3. Further rise causes more cooling and condensation clouds and rain form 4. Cool air descends and replaces warm air. The process repeats.

Drip

when water drips from leaves onto the ground

3 types of runoff- ground water flow

where once infiltrated into the soil, water percolates into the bed rock and joins ground water stores. From here it may flow laterally through the rock as ground water flow or base flow.

3 types of runoff- Surface runoff or overland flow

where surplus water runs through gullies or across the ground surface to the closest river channel

3 types of runoff- through flow

where the water has infiltrated the soil and begins to flow laterally through the soil towards a water course


Ensembles d'études connexes

Advanced Organizational Behavior - Exam #4

View Set

Lista de nombres y su significado

View Set

Physical Science - Chapter 1 Reading Check Quiz

View Set