Water and carbon cycle - topic cards

Factors affecting rate of evaporation:

- amount of solar energy - availability of water - humidity of air; closer the air to saturation point the slower the rate of evaporation - temp. of the air; warmer air can hold more water vapour than cold air

Some of the advantages of draining marginal farmland:

- build-up of an improved soil structure, making it more friable and easier to work. It also makes it easier to achieve greater root penetration. enabling roots to travel faster and further - improved aeration, makes conditions re favourable for microorganisms to thrive. Increases the rate at which organic matter is broken down into humus and pant nutrients are mineralised into an available form. It also provides the necessary supply of air for root cell respiration - increases aeration increases the ease with which the soil can be warmed. This can make possible earlier sowing of seeds, with greater likelihood of improved germination - heavy machinery can work on the land without danger of compaction - larger numbers of animals can be allowed to graze the land, once again without compacting the soil

Differences between Amazon rainforest and pasture land it is generally replaced with:

- forests absorb approx. 11% more solar radiation - average temp rainforest - 24.1 pastures - 33 - daily temp variation of Amazon soils at 20cm doesn't exceed 2.8 degree c, though pastures 8 - moisture content in pasture soil 15% less than amazon soil - Amazon - deeper forest roots pump more soil moisture to surface, producing 20-30% more air humidity and consequently 5-20% more precipitation than pastures

Several important points about the climate, land surface and water cycle:

- if deforestation does not cause decreased rainfall via atmospheric feedbacks discharge will likely be significantly increased throughout the entire southern Amazon - if rainfall does decrease via atmospheric feedback the resulting decrease in river discharge may be greater than the changes without feedbacks - changes in water resources caused by atmospheric feedbacks will not be limited to those catchment areas where deforestation has occurred but will be spread unevenly throughout the whole Amazon basic by atmospheric circulation

Some of the disadvantages of draining marginal farmland:

- insertion of drains artificially increases the speed of through flow in soil. Much ore water reaches watercourses more quickly than before drainage. This can increase the likelihood of flooding and increase the range of flows in rivers. It is interesting to note that before the drainage of many floodplains in the UK, river regimes were much more even - dry tips can be subject to wind erosion if not protected. Soil loss by wind erosion has mainly been documented for sandy and peaty soil in the Eastern countries of England - nitrate loss. It can lead to eutrophication. Water draining from fields finds its way into local watercourses. There it enriches ponds etc. with nitrogen or phosphorus. It causes algae and higher forms of plant life to grow too fast. This disturbs the balance of organisms present in the water and the quality of the water concerned

Impact on the land

- more wildfires are being extinguished. Leads to build up of woody material that stores carbon. Fires ad deforestation elsewhere as led to increased atmospheric carbon - agriculture more intensive. More crops from less land increases carbon take up - increased temp. warmed up land. In Tundra areas warming of land increases rate of decay of accumulated dead organic matter leaving to relate of carbon. ethane etc. - farmland in mid-latitudes abandoned in early 20th century. Farmland replaced by trees which store much more carbon than crops - more carbon available in atmosphere results in mope photosynthesis and plant growth. Called 'carbon fertilisation'. Growth limited reached when available water and nutrient limits are reached - carbon dioxide taken up by plats has increased since 1960. 25% of emissions removed by plants - increased temp. have led to increase in the length of growing season. More plant growth and higher evapotranspiration rates require more water. Growth limited by water availability

Variations in soil moisture graphs due to climate

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UK rainfall and rivers

1,500 river systems in UK. UK rainfall evenly distributed throughout the year with a slight Winter/Autumn maximum, particularly in West. seasonal variations in temp. and sunshine mean that evapotranspiration losses are heavily concentrated in the Summer. UK rivers have a marked seasonality in their discharge with a late Summer/early Autumn minimum

Earths 4 major subsystems:

1. Atmosphere 2. Lithosphere 3. Hydrosphere 4. Biosphere Each of these are open systems that from part of a chain, a cascading system

The storm (flood) hydrograph

A graph of the discharge of a river leading up to and following a storm or rainfall event. They are important because they predict how a river might respond to a rainstorm. Help in managing the river. Starts wth the base flow. River is fed by through flow of soil water and groundwater. Slow movement of water means that the changes in discharge are small. Storm water enters drainage basin and the river begins to be fed by much more fast-moving water. Discharge rises, as shown by the rising limb of the storm hydrography. Eventually reaches a peak discharge, highest flow in the channel for that event. Tie taken from peak rainfall to peak discharge is lag time. Discharge begins to fall as shown by the receding/falling limb of the graph. When all the storm water has passed through, the river returns to its base flow

River regimes

Defined as 'the variability in its discharge throughout the course of a year in response to precipitation, temperature, evapotranspiration ad drainage basin characteristics'

Permafrost

Defined as ground that remains at or below 0 degrees C for at least 2 consecutive years. Thickness varies from less than a metre to 1,500m. Most of the permafrost toady formed during glacial periods and has persisted through warmer interglacial periods, including the Holocene (last 10,000 years). Subsea permafrost occurs at close to O degree C over large areas of the Arctic continental shelf., where it formed during the last glacial period on the exposed shelf landscapes when sea levels were lower. Permafrost is found beneath the ice-free regions of the Antarctic continent and also occurs beneath areas in wick the ice sheer s frozen to its bed. Permafrost has begun to melt as climate warms. This melting is releasing large amounts of carbon dioxide and methane, potentially affecting global climates

The biosphere

Defined as total sum of all living matter. Terrestrial biosphere - 3,200 GtC

Deforestation - how it affects the water cycle

Deforestation and forest degradation result in a complex set of changes to streams of all sizes. When forests are removed the new vegetation generally has fewer leaves and shallower roots. This means it uses less water than the forest it replaces. the result is that less water evaporates from the land surface to be returned to the atmosphere; more water runs off of the land and stream flow is increased. The amount of change that occurs depends o local conditions including the amount of rainfall, how much watershed is deforested, topography, soils and the land use after deforestation. Studies have shown that there is little effect with less than 20% of a basin deforested but anything over 50% there is a big effect. These changes occur at the local scale, but rivers of all sizes are affected when deforestation is extensive

Deforestation

Deforestation occurs because there is need for extra agricultural land, logging operations, access roads and growing urban sprawl. The FAO estimates that about 13 million ha, equivalent to the size of Greece, worlds forests are cut down and converted to other land uses annually. Planting of trees has resulted in forests being established or expanded on to abandoned agricultural land. This means the world has lost about 3% of its forests in the period 1990 to 2005. The worlds rainforests could completely vanish in 100 years at the current rate of deforestation. When forests are cleared for conversion to agriculture or pasture, a large proportion of the above-ground biomass may be burned, rapidly releasing out of its carbon into the atmosphere. Forest clearing also accelerates the decay of dead wood, litter and below-ground organic carbon. Forest souls are most, but without the shad from tree cover they quickly dry out. Trees also help maintain the water cycle by returning water vapour back into the atmosphere through transpiration. Without tress to fill these roles, many former forestlands can quickly become barren deserts

Ocean acidification

About 30% of carbon released into atmosphere has diffused into ocean through direct chemical exchange. Dissolving carbon dioxide in the ocean creates carbonic acid. Makes the slightly alkaline ocean become little less alkaline. Since 1750, pH of oceans surface 30% change in acidity. Carbonic acid reacts with carbonate ions in the water to form bicarbonate. Those same carbonate ions are what animals like coral and many planktonic species need to create their calcium carbonate shells. With less carbonate available, animals need to expend more energy to build shells. As result, shells are thinner and more fragile. coral reefs provide food and livelihood for 500 million people worldwide. Loss and consequent fall in marine biodiversity threatens survival of coastal communities. Polar and sub-polar marine ecosystems are projected to become so low in carbonate ions that waters may actually become corrosive to unprotects shells and skeletons of organisms currently living there. The more acidic seawater is, the better it dissolves calcium carbonate rocks. Reaction will allow the ocean to soak up excess carbon dioxide because the ire acidic water will dissolve more rock, relate more carbonate ions and increase the oceans capacity to absorb carbon dioxide

Volcanic activity

According to USGS " the carbon dioxide released in recent volcanic eruptions has never caused detectable global warming of the atmosphere" the warming effect of emitted carbon dioxide is counterbalanced by the large amount of sulphur dioxide that is given out. Conversion of this sulphur dioxide to sulphuric acid, which forms fine droplets, increases the reflection of radiation from the Sun back into space, cooling the Earth's lower atmosphere

Soil storage

Amount off water stored in the soil. Soil consists of solid particles with pore spaces between them. These pore spaces can be filled with air/water. Amount of pores differ for different soils. Pores in clay soil account for 40-60% of its volume. in fine snd this can be 20-45%

The effects of deforestation on the water cycle - localised deforestation

Before deforestation much of the high precipitation is returned to the atmosphere by evapotranspiration. Overland flow is minimal . Most of the water that reaches the forest floor infiltrates into the soil and travels slowly to the river by through flow, maintaining a steady flow in the river. After deforestation, although the precipitation stays the same, the evapotranspiration is lower because the replacement vegetation has smaller leaves and roots and is less dense. Overland flow and through flow occur because of the lack of vegetation. The lads to increased discharge and flashiness This can cause localised flooding

Drivers of change - Amazon

Between 2000-2007 Amazon deforest at over 19,000 km squared/year. Area larger than Greece destroyed. Brazil is 4th largest climate polluter, 75% of their greenhouse gas emissions attributed to deforestation and land use change, 59% of this is from loss of forest and burning in the Amazon. Removal of forest through slash and burn - reduces retention of humidity in soils top layer down to 1 metre - facilitates sudden evaporation of water previously retained in forest canopy - increased albedo and temp - reduces porosity of soil, causing faster rainfall drainage, erosion and silting of rivers and lakes Moisture that evaporates from defrosted areas forms shallow cumulous clouds which usually don't produce rain. Forests emit salts and organic fibres along with water when they transpire. Act as condensation nuclei and assist in cloud and rain formation. Loss inhibits formation of clouds and reduces rainfall. If destroyed carbo store will be released into atmosphere.

Calcium carbonate

Calcium carbonate is precipitated from calcium and bicarbonate ions in seawater by marine organisms like molluscs. When these creatures die their skeletons sink to the bottom of ocean and collect sediment. Burial by overlaying layers of sediment can eventually turn these sediments into sedimentary limestone. Coral also extracts calcium carbonate from seawater. These creatures live and eventually die in the same location. Dead coral is built upon by later generations of coral. The carbon is now stored below the sea floor in layers of limestone. Tectonic uplift can then expose buried limestone e.g. in Himalayas some of highest peaks made from material that was once at the bottom of the ocean Tectonic forces cause plate movement to push sea food under continental margins in process of subduction. Carbonaceous sea floor deposits are pushed deep into Earth where heat up, eventually melt, can rise back up to surface through volcanic eruptions or in seeps, vents and carbon dioxide rich hot springs. Carbon dioxide returns back to the atmosphere. Weathering, burial, subduction and volcanism control atmospheric carbon dioxide concentrations over time periods of hundreds of millions of years

Carbon capture ad sequestration (CCS) technologies

Carbon capture and storage is a technology that can capture up to 90% of carbon dioxide emissions produced form the use of fossil fuels in electricity generation and industrial processes, preventing the carbon dioxide from entering the atmosphere. CCS chain: Capturing - allow separation of carbon dioxide from gases produced in electricity generation and industrial processes by one of three methods: pre-combustion capture, post-combustion capture and oxy-fuel combustion Transporting - by pipeline or by ship to storage location Storing - underground in depleted oil and has fields, deep saline aquifer formations severe kilometres below the surface or the deep ocean

Some important examples of carbon compounds:

Carbon dioxide - gas found in atmosphere, soils and oceans Methane - gas found in atmosphere, soil, ocean and sedimentary rocks Calcium carbonate - should compound found in calcareous rocks, oceans, skeletons and shells of ocean creatures Hydrocarbons - solids, liquids or gases usually found in sedimentary rocks Bio-molecules - complex Carbon compounds produced in living things. Proteins, carbohydrates, fats and oils and DNA

Land use change

Carbon dioxide emissions that result from land use change (mainly deforestation) account for up to 30% of anthropogenic carbo dioxide emissions

Impact on the atmosphere

Carbon dioxide, methane and halocarbons are greenhouse gases. Without greenhouse gases, the Earth would be a frozen - 180 degrees celsius. The problem that is facing us is an enhanced greenhouse effect. This where the extra carbon dioxide and other greenhouse gases in the atmosphere are causing something called radiative forcing - energy is constantly flowing into the atmosphere in the form of sunlight that always shines on half of the Earth's surface. Some of this sunlight is reflected back to space and the rest is absorbed by the planet. Some of the absorbed energy is radiated back into the much colder surrounding space as infrared energy. If the balance between the incoming and the outgoing energy is anything other than 0 there has to be some warming going on. The amount that the Earths energy is out of balance is caed the radiative forcing and is a measure of recent human activities. it is immured in watts/metre squared of the Earths surface. Current level - 1.6 If carbon dioxide levels continue to rise experts predict that the Earth will become much hotter

The atmosphere

Carbon in atmosphere 0.04%. This low concentration belies its importance to the planet and all life on it. Due to human activities, the present concentration is higher than it has been fro at least 800,000 years. CO2 is a potent greenhouse gas and plays a vital role in regulating the Earth's surface temp. Recent global warming attributed mainly to increasing industrial CO2. Atmospheric carbon measured at the Mauna Loa Observatory (MLO) on Hawaii since 1958. It is part off the American National Oceanic and Atmospheric Administration (NOAA). easements show increased from 317.7ppm in 1958 to 400.3ppm in 2015. This largely due to anthropogenic sources. The graph of this change is called the Keeling curve

The carbon cycle

Carbon is one of the most chemically versatile of all the elements and is found in all life forms. Carbon follows a route round earth called the carbon cycle. It is transformed from organic carbon (in plants and trees) to inorganic Carbon and back again

Movement of Carbon

Carbon moves in a continuous cycle. The cycle consists of several carbon stores. The processes by which the carbon moves between these stores are known as transfers or fluxes. If more carbon enters a store than leaves it, that store is considered a net carbon sink. If more carbon leaves a store than enters it, the store is considered a net carbon source

Ocean salinity

Decrease in salinity in the deep north Atlantic. Probably caused by higher lobes of precipitation and higher temperatures. Precipitation leads to higher river run-offs that eventually reach the sea. Higher temperatures are causing melting of the Greenland ice sheet and many alpine glaciers. This will lead to an increase in fresh water reaching the oceans. Changes linked to possible slowing down of large-scale oceanic circulation ninth North-East Atlantic. This will have a effect on climate of North West Europe

Human factors affecting a hydrographs shape

Deforestation reduces interception rates allowing rainwater to hit the surface directly. The lack of vegetation roots reduces the infiltration rate into the soil. These both lead to rapid overland flow and flashy hydrographs. Deforestation also exposes the soil to greater rates of erosion, which leads to sedimentation of the channel. This reduces the tankful capacity of a river and can lead to a greater chance of flooding Afforestation has the opposite effect making it a useful flood prevention measure Agriculture: - ploughing breaks up the tops and allows greater infiltration, subduing hydrographs. Tis can be enhanced by control ploughing white furrows are created that run directly down slop, the they can act as small stream channels that lead to flashier hydrographs. Ploughing wet soils can cause impermeable smears in the subsoil called plough plans. These inhibit percolation eating to greater surface flows Terracing on hillsides stops movement of water downhill and subdues hydrographs Grass crops increase infiltration and lead to subdued hydrographs large number son animals on small areas can impact soils leading to overland flows Growth f urban areas and other large impermeable surfaces such as roads lead to flashy hydrographs. This is exacerbated by the fact that settlements have been built on floodplains. This urban growth leads to the expansion of built-up, impermeable surfaces such as roads, car parks, shopping centres etc. Most settlements are designed to transfer water as quickly as possible away from human activity to the nearest river. This is achieved through road camber, building design and drainage systems. In many cities in the UK there has been a continued favour of paved drives. Due to the growing number of 2/3 car families, an area of vegetated garden equivalent to 300 hectares a year was lost in London between 1998 and 2006 Some soft engineering flood management shoes attempt to reduce flashiness of a rivers flood hydrograph. Afforestation increases interception and infiltration. The slows down the progress of water to the river channel and subdues any changes in discharge Water abstraction reduces the base flow and so more water must reach the channel before it reaches bankfull capacity

Physical factors affecting a hydrographs shape

Drainage basins that are more circular in shape lead to more flashy hydrographs than those that are long and thin because each point in the drainage basin is roughly equidistant from the measuring point of the river Drainage basins with steep sides tend to have flashier hydrographs than gently sloped river basins. This is because water flows more quickly on the steep slopes whether as through flow or overland flow and so gets to the river more quickly If the drainage basin is already saturated by antecedent rainfall then overland flow increases because infiltration capacity has been reached. Since overland flow is the fastest pf the transfers the lag time is reduced. Peak discharge is higher resulting in a flashier hydrograph If the soil or rock type within the river basin is impermeable (clay soil or shale rocks) overland flow will be higher. Through flow and infiltration will also be reduced, meaning a flashy hydrograph. The same can be said of surfaces baked hard by the sun during a long period of dry weather pr frozen surfaces resulting from cold weather Drainage basins underlain by sandstones have a subdued hydrogaph because the water soaks into this porous rock Thick vegetation cover in drainage basins will have a significant effect on a storm hydrograph. Vegetation intercepts the precipitation,, holing the water on its leaves; this slows the movement of rainwater to the ground and so to ever channels. Water is also lost due to evaporation and transpiration from vegetation surfaces reducing how much gets to the river. This subdues the storm hydrograph, increasing lag time and reducing peak discharge Amount and intensity of precipitation can affect a storm hydrograph. Heavy storms with a lot of water entering the drainage basin over a short time result in higher discharge. The type of precipitation can also have an impact. The lag time is likely to be greater if the precipitation is snow rather than rain. This is because snow takes time to melt before the water enters the river channel. When there is rapid melting of snow the peak discharge could be high Large drainage basins catch more precipitation and so have a higher peak discharge compared to smaller basins. Smaller basins generally have a short lag time because precipitation does not have as far to travel

Terrestrial water

Falls into 4 broad categories: 1. Surface water 2. Groundwater 3. Soil water 4. Biological water

Rate of movement

Fastest movement of water is along surface as there are few obstacles slowing it down. urban surfaces have especially fast water movement because they are designed to move water by having strategically placed slopes and very smooth surfaces. Water over through soil at slower rate. Under woodland areas there are many channels created bye lots as well as burrowing animals that allow relatively free movement. Clay soils retain water, hindering any movement. Can dry out from the surface down before they allow horizontal transfer. Once on rocks below soil rate of transfer slows considerable. Groundwater can be held for millennia

The differecnes in groundwater levels for January 2000 and Janaury 2014:

Groundwater levels in West London have risen due to limited abstraction in this area, in the order of 4-8m since 2000 which has leveled off in recent years Central and East London groundwater levels have fallen in the order of 5-7 million since 2000 as a result of increased abstraction Groundwater levels have fallen more than 2m across much of South London, which falls to 12m concentrated around the many large public water supply abstractions East London, where there are chalk outcrops around the River Thames from Greenwhich to Woolwich, there is a risk of saline intrusion. When groundwater levels near the river are lower than the water level in the River Thames, saline river water can enter the chalk aquifer

Different shaped hydrographs

Hydroghraphs that have a short lag time, high peak discharge, steep rising and falling limbs are described as being flashy. Others are a lot more subdued with gentle rising and falling limbs, long lag times and low peak discharge. The shape is determined by physical and human factors

Ice sheets

Ice sheet is a mass of glacial land ice expanding more than 50 thousand km squared. 2 major ice sheets cover out of Greenland (covering most of island of greenland - 1.7 km squared) and Antarctica which contain 99% of freshwater on Earth. Ice sheets form where snow falls in Winter doesn't melt entirely over Summer. Over long time, snow layers pile up into thick masses of ice, growing thicker and denser as the weight of the new snow compresses the older ayers. Ice sheets in constant motion slowly flowing downhill under own weight. Contain enormous quantities of frozen water/ If greenland ice sheet melted sea level would rise about 6m. If Antarctic ice sheet melted, sea level would rise by about 60m

Infiltration capacity and surface storage

If rainfall intensity greater than infiltration rate then soil will reach infiltration capacity.and soil will be saturated. Water builds up on surface as surface storage (puddles). Water usually disappears into ground faster than it rains. Water can only build up on surface after long period of rain, an intense rainstorm or on an impermeable surface. Much of surface storage then evaporates back into atmosphere and is lost to drainage basin. Difficult to separate evaporation and transpiration so total outputted from the system is evapotranspiration, the two put together. When surface stores are full then overland flow or sheet flow will begin on slopes. Very fast flow, rapidly reaching nearest channel

Oyster larvae off the coast of Oregon

In 2007, farmed oyster larvae began dying in the millions. Losses directly linked to ocean acidification. Took a significant toll on coastal communities - cost millions of dollars in lost sales. Acidic seawater today holds carbon dioxide absorbed approximately 30 to 50 years ago.

Soil water

Key variable in controlling the exchange of water and heat energy between the land surface and the atmosphere through evaporation and plant transpiration. Soil moisture pays an important role in the development of weather patterns and he production of precipitation

Vegetation change

Massive int loss of forests in Amazon basin, about 3.6 million hectares per year between 2000-2010. Most caused by deforestation some result of climate change. Some species limited by tolerance to temp change, drought and seasonality. Climate change affect species by directly altering conditions need to grow and survive. 2009 study concluded that 2 degree temp rise above pre-industrial levels would see 20-40% of Amazon die off within 100 yrs. 3 degree rise would see 75% of forest destroyed while 4 degree would kill 85%

Climate change - Amazon

Mean temp increase of 0.26 degree celsius every ten years since mind 1970s. Predicted by 2050 Amazon tim increase by 2-3 degrees. Evidence of more frequent and increased extremes in temp

Mitigation within the aviation industry

Movement management - towing aircraft while on the ground, avoiding circling, queuing, adopting fuel efficient routes Flight management - 100% occupancy of seats, cruising at lower speed, matching an aircraft to the route Design and technology - increased engine efficiency, increased use of biofuels, improved aerodynamics, reduced weight of aircraft and engines, carbon capture within the engines, maximising the number of seats per aircraft

Sea ice and ice shelves

Much of Artic ocean and waters surrounding Antarctica is frozen.Sea ice from when water i the oceans is cooled to temp. below freezing. Sea ice does not raise sea level when it melts because it from from ocean water. Closely lined with planets climate so scientists are concerned with its recent decline. Ice shelves are platforms of ice that from here ice sheets and glaciers move out into the oceans. Exist mostly in Antarctica and greenland. Icebergs are chunks of ice that break of glaciers and ice shelves and drift in the oceans. Raise sea level only when they first leave land and push into the water but not when they melt

Mitigation - Amazon

National and international agreements: - Latin American Technical Cooperation Network on watershed management - TARPATO process to hep achieve harmonious forest development - Amazon Corporation Treaty Organisations (ACTO) to promote harmonious development Mitigation: - creation of national parks and forest reserves - Tumucumaque national park - 3.84 million hectares - forest biofuel production could compete with ethanol production from sugar cane by 2030 - reforestation: much of Brazil's industrial timber comes from planted forests which make up only 2% of forest area - enrichment of degraded forests using native species

Transport within the global water cycle

Net transport of 38 units from ocean to land with same amount returning by rivers to ocean. Amount of precipitation over continents is almost 3 times as high, indicating a considerable recirculation over water over land. Recirculation has a marked annual cycle as well as having large variations between continents. Recirculation larger droning summer for tropical land areas. Most ion water from Pacific ocean recirculates between different parts of Pacific itself and there is little net transport towards land. Pattern of water exchange between ocean and land different in Atlantic ocean, with the rest essentially from Indian ocean. Most of continental water for north and south America, Europe and sAfrica emanate from the Atlantic and is also returned to the Atlantic by rivers

Water balance formula

Precipitation (P) = discharge (Q) + evapotranspiration (E) +/- changes in storage

Origins of Carbon on earth

Primary source is earths interior. Stored in mantle when earth formed. Escapes form mantle at constructive and destructive plate boundaries as well as hot spot volcanoes. Much of CO2 released at destructive margins is derived from the metamorphism of carbonate rocks subducting with the ocean crust. Some Carbon remains as CO2 in atmosphere, dissolved in cleans, held in biomass, bound in carbonate rocks. Carbon denies into long term storage by burial of sedimentary rock layers especially coal and black shales and carbonate rocks like limestone

Water abstraction

Problems can occur when the demand for water exceeds the amount available during a certain period. This happens frequently in areas with low rainfall and high population density or in areas with intensive agricultural or industrial activity. In many areas of Europe, groundwater is the dominant source of fresh water. In a number of places water is being pumped from beneath ground faster than it is being replenished. This results in sinking water tales, empty wells, higher pumping costs and in coastal areas the intrusion of saltwater from the sea which degrades the groundwater. This is happening along Mediterranean coastlines . In Malta, most groundwater can no longer be used for domestic consumption or irrigation because of saline intrusion, and the country has resorted to expensive desalinization plants

Climate change mitigation

Refers to efforts to reduce or prevent emission of greenhouse gases

Case study of a river catchment at a local scale: River Brock, Lancashire

Regime: Lower than average flow all year with a late winter maximum and low flow in the summer. 2012 was a particularly wet year in this part of the country. Flooding: most serious dig to affect the village of St. Michael's on Wrye was in October 1980 when there was a combination of intense and prolonged rainfall. Flood protection was put in place: - area of St.Michael's to North f the River Wyre the Environment Agency constructed a flood storage basin - 1.7 million metres cubed of floodwater - Embankments were raised and strengthened in lowland areas close to River Wyre - warnings issued, sandbags given out by local council, which maintains a store of 2,000

Run-off variation

River flow is measured by measuring the discharge of a river. Defined as the volume f water passing a measuring point in a given time. Calculated by multiplying the cross-sectional area of the river by its velocity at the measuring point. It is measured in metres cubed per sec or cumecs. Discharge is the combined result of the many climatological and geographical factors which interact within a drainage basin. Knowledge of discharge is important in assessment and management f water resources, design of water-related structures and flood warning and alleviation schemes. Can also help in developing hydroelectric power. Climate change expected to impact very unevenly on river discharge patterns, keeping rocks is the key to identifying, quantifying and interpreting hydrological trends

Melting sea ice

Satellites monitoring sea use in Arctic measured its retreat at 40% in last 35 yrs. When ice starts to melt the ocean is able to absorb more sunlight, which in turn amplifies the warming that caused it to melt in the first place. oss of ice bound algae affects marine predators all the way up the for chain, from krill and fish to seals, walruses and polar bears. animals like the polar bear rely on sea ice to get to heir main food source of seals can no longer travel upon it

Sea level rise

Sea levels worldwide have been rising at a rate of 3.5mm/year. Causes of this change: Melting of terrestrial ice - increasing temperatures increased rate of summer melting as well as a drop in snowfall in shorter winters. Imbalance results in significant net gain in water entering oceans Thermal expansion - when water chats up, it expands. Warmer oceans have a greater volume so occupy more space

Carbon - Amazon

Stores 80-120 billion tonnes of carbon. Forms a carbon sink. Rising productivity of rainforests is due to sequestering of increased carbon dioxide concentrations in the atmosphere. Negative feedback. Study in 2015 showed that Amazon losing tis capability to absorb carbon dioxide from the atmosphere. An increase in carbon dioxide led to a growth spurt for the Amazon's trees however the growth stimulation feeds through the system, causing tries to live faster and so die younger. This has led to a surge in the rate of trees dying across the Amazon

Soil drainage

Subsurface drainage removes excess water from the soil profile. Carried out through network of perforated tubes installed 60-120cm below soil surface. Tubes are commonly called 'tiles'. Most common type of tile is corrugated plastic tubing with small perforations to allow water entry. When the water table in the soil is higher than the tile, water flows into the tubing, either through holes in the plastic tube or through the small cracks between adjacent tiles. This lowers the water table to the depth of the tile over the course of several days. Drain tiles allow excess water to leave the field, but once the water table has been lowered to the elevation of the tiles, no more water flows through the tiles. In UK most drain tiles haven't flowed between June and October

Ice caps

Thick layers of ice on and that are smaller than 50,000 km squared. Usually found in mountainous areas. Tend to be dome shaped and are centred over highest point of upland area. Flow outwards covering almost everything in their path and becoming the major source for many glaciers. The Furtwangler glacier on Kilimanjaro, at 60,000 metres squared is Africa's only remaining ice cap. It is melting rapidly and may soon disappear

Alpine glaciers

Thick masses of ice found in deep valleys or upland hollows. Most are fed by ice from okie caps or smaller corrie glaciers. These glaciers important in Himalayas where about 15,000 Himalayan glaciers form a unique reservoir which supports rivers such as Ganges which are the lifeline of millions of people in South Asian countries

Water abstraction from the chalk of Southern England

Water within the chalk aquifer of Southern England is replenished by rainfall that lands on the exposed chalk hills of the North and South Downs and the Chilterns. Normally recharge takes place over the Winter months when potential evapotranspiration is low and soil moisture deficits are negligible. Groundwater amounts vary seasonally, with levels rising from Autumn through Winter into Spring. During the Summer months, potential evapotranspiration generally exceeds rainfall, soil moisture deficits build up and little percolation takes place. Summer water still leaves the chalk from springs as well as boreholes. Rivers fed by groundwater from chalk aquifers can have intermittent sections. These streams are referred to as 'bournes' are a natural characteristic of chalk downlands. Some of the acute problems with over-abstraction have been found in chalk stream systems, where up to 95% of the flow is derived from underground aquifers. The catchments of chalk streams provide underground reservoirs of generally high quality groundwater can be abstracted for public supply.Abstraction for public water supply and industry has dramatically reduced the flow in many chalk streams and sometimes completely dried up sections of these important rivers particularly during dry summers when demand is highest. This also has an impact on local communities, resulting from the inability to fish

Dynamic equilibrium

Wen there is a balance between the inputs and outputs in a system. The sores stay the same. If one element in system changes, e.g. input increases without corresponding change in outputs, then the stores change and the equilibrium is upset. This is called feedback. Positive feedback- effects of action are amplified or multiplied by subsequent knock-on or secondary effects Negative feedback - effects of an action are nullified by its subsequent knock-on effects

Geo-sequestration

When carbon dioxide is stowed i deep geological formations it is known as geo-sequestration. Carbon dioxide converted into high pressure liquid like form known as 'supercritical' carbon dioxide which behaves lied a runny liquid. injected directly into sedimentary rocks

Farming practices

When soil is ploughed, the soil layers invert, air mixes in, and soil microbial activity dramatically increases. It results in soil organic matter being broken down much more rapidly, and carbon is lost form the soil into the atmosphere. Emissions from the farm tractors increases carbon dioxide levels in the atmosphere. Largest source of carbon emissions within agriculture is enteric fermentation - methane produce by livestock. Greenhouse gases resulting from biological processes in ice paddies that generate methane make up 10% of total agricultural emissions, while the burning of tropical grasslands accounts for 5%

Condensation is the direct cause of all forms of precipitation:

When the temp. of the air is reduced to dew point but its volume remains constant. This occurs when: - warm moist air passes over a cold surface - on a clear Winters night heat is radiated out to space and the ground gets colder, cooling the air directly in contact with it When the volume of air increases but there is no addition of heat (adiabatic cooling). This happens when air rises and expands in the lower pressure the upper atmosphere. This can occur when: - air is forced to rise over hills (orographic effect) - masses of air of diff. temp. and densities meet. The less dense warm air rises over the denser cold air (frontal effect) - localised warm surfaces heat the air above. The expands, becomes less dense and rises (convectional effect)

The effects of deforestation on the water cycle - extensive deforestation

Where deforestation is extensive, positive feedback can occur in the basin hydrological system. This can be because evapotranspiration is low, much of the water leaves the area in the river channel rather than being recycled continuously between the forest and the atmosphere. Once the water has left the area there is less water vapour available in the atmosphere for precipitation and so precipitation levels fall. Less water gets to the river channel ad the flow is reduced

The geological component

Where it interacts with the rock cycle own the processes of weathering, burial, subduction and volcanic eruptions. Carbon dioxide is removed form the atmosphere by dissolving in water and forming carbonic acid: carbon dioxide + water = carbonic acid Weak acid water rains down on Earth, it reacts with minerals in Earths surface, slowly dissolving them into their component ions through the processes of chemical weathering. Component ions are carried in surface waters e.g. rivers to the ocean . In ocean they settle as minerals e.g. calcite, a form of calcium carbonate

Water balance

Within drainage system, balance between inputs and outputs is known as the water balance or budget. Rivers only occur if stores are able to release water, there is direct precipitation or there is overland flow into the river. As a river moves downstream it is fed by its tributary system. Discharge levels rise and fall, often showing an annual pattern (called the rivers regime). Also vary in short term following heavy rainfall

Evaporation

occurs when energy from solar radiation hits the surface of water or land and uses liquid water to change state from liquid to gas

Transpiration

where water is transported forth roots of a plants to tis eaves and the lost through pores on the leaf surface (stomata). Leaves also intercept rain as it falls, and the rate can be evaporated before it reaches the soil. Ad water evaporates it uses energy in the form of latent heat so cools its surroundings

The major stores of Carbon

A gigatonne of Carbon is used by the UNs climate change panel, IPCC, to measure amounts of Carbon in various stores it amounts to about 1 billion tonnes . Transfers of Carbon within the cycle is measured in gigatonnes of Carbon per year

Soil moisture graph

A soil moisture graph shows the relationship between precipitation ad potential evapotranspiration

What is a drainage basin?

area that supplies driver with its supply water. This includes water under the water table as well as soil water and any surface flow. Drainage basins are separated from one another by high land called a watershed

List the 5 locations of cryospheric water

1. Sea ice - Ross ice shelf 2. Ice caps - the Iceland ice cap 3. Ice sheets - Greenland ice sheet 4. Alpine glaciers - Mer de glace, France 5. Permafrost - the Alaska North Slope

Example of CCS in action

110-megawatt coal poer and CCS plant in Saskatchewan, called Boundary Dam.. Captures 90% of its carbon dioxide output. Carbon dioxide eventually piped 66km to Weyburn oil unit and infected imp oil bearing formation at 1,500m depth. This adds pressure and helps push more oil out of the ground, process called enhanced oil recovery

Water and carbon in the atmosphere

300 billion trees and 15,000 species store 1/5 of global carbon. Covers around 5.5 million km squared and is speed across 9 countries

Cryospheric processes

5 major glacial periods in Earths history. Most recent started 2.58 million years ago and continues today called Quaternary glaciation. During this time: - glacial periods when sea level was 120m lower due to volume of ice on land - interglacial periods when global ablation exceeds accumulation and the hydrological cycle as we know it today returns Permafrost is formed when air temperatures are so low that they freeze any soil and groundwater present. It rarely occurs under ice because the temperatures are not low enough

Effects of the changing carbon budget

500 million years ago atmospheric carbon dioxide was 20 times higher than present values. It dropped, then rose again 200 million years ago to maximum of 4 to 5 times present levels. It then follows a slow decline until recent pre-industrial time. To calculate the effects of the changing levels of carbon we use computer models . They can have between 50-100 equations interacting to describe al the different processes of the carbon cycle. Result is that models only predict possibilities not probabilities

Improved aviation practices

Annual emissions - 705 million tonnes of carbon dioxide in 2013. Airbus A380 and Boeing 787 both sue less than 3 litres of fuel per 100 passenger km

Through flow

Any lateral movement of soil water downslope is through flow and eventually reaches nearest channel. Tens to be much slower than overland flow. Generally, more vegetated the area the faster the rate of through flow because it is aided by root channels in the soil

Condensation

As air cools it is able to hold less water vapour. If cooled sufficiently then it will get to a temp. at which it becomes saturated. Known as the dew point temp. Excess water in the air will be converted to liquid water in process of condensation. Water molecules need something o condense on. These can be tiny particles that are collectively called condensation nuclei, or surfaces that are below the dew point temp. Iff the surface is below freezing pint then after vapour sublimates , chasing firmly from gas to soil in the from of hoar frost

Water - Amazon

Average discharge into Atlantic ocean from Amazon - 175,000 metres cubed per second, around 15% of fresh water entering the oceans each day. Rio Negro, tributary of Amazon, second largest river in world, 100m deep and 14km wide near mouth at Manuas, Brazil. Sewage rainfall across Amazon basin is 2,300mm annually. Up to half of this rainfall intercepted by forest canopy and re-evaporated into atmosphere. Additional water evaporates from ground and rivers, related into atmosphere by transpiration from plant leaves. About 48% of evapotranspiration falls again as rain. Only about 30% of the rainfall reaches the sea. Rest is caught up in this constant closed system loop

Decomposition

Decomposition includes physical, chemical and biological mechanisms that transforms organic matter into increasingly stable forms. The decomposition prices is carried out by decomposers whose special role is to break down the cells and tissues in dead organisms into large biomolecules and then break those biomolecules down into smaller molecules and individual atoms. Decomposition ensures that the important elements of life can be continually recycled into the soil and made available for life

Changing rural land use

Carbon stores can be improved by making sure that carbon inputs to the soil are greater than carbon losses from it. Grasslands - global greenhouse gas mitigation potential of 810 million tonnes Soil carbon storage grasslands can be improved by: - adding manures and fertilisers that have impact on soil organic carbon (SOC) levels through the added organic material - revegetation can increase productivity, resulting in more plant litter and underground biomass, adding to SOC stock - irrigation can improve plant productivity Croplands - mulching can add organic matter - reduced or no tillage (ploughing and harrowing) avoids accelerated decomposition of organic matter. Also prevents the break-up of soil aggregates that protect carbon - rotations of cash crops potential to increase biomass returned to soil - improved crop varieties Forested lands and tree crops able to reduce carbon dioxide emissions t the atmosphere by storage large stocks of carbon both above and below ground - retention of existing forest - reforesting degreased lands and increasing tree density and therefore carbon density - trees in croplands Important to note: many of these mitigation schemes have different and unwanted side effects

Rivers - Amazon

Changes in total precipitation, extreme rainfall events and seasonality may: - lead to overall reduction in river discharge - increase in silt washed into rivers which could disrupt river transport routes - lead flash flooding - destroy freshwater ecosystems - could remove source of protein and income to local inhabitants - destroy water supply which fulfils needs of Amazonian peoples Warming water temperatures may: - kill off temperature dependant species - change biodiversity of river system by introducing new species and killing others - reduce water-dissolved oxygen concentrations which could destroy eggs and larvae, rely on dissolved oxygen for survival

Combustion

Combustion occurs when any organic material is reacted in the presence of oxygen to give off the products of carbon dioxide, water and energy. Organic material can be any vegetation or fossil fuel such as natural gas ,oil or coal. Organic materials contain at least carbon and hydrogen and may include oxygen. if other elements are present they ultimately combine with oxygen to from a variety of pollutant molecules such as sulphur oxides and nitrogen dioxide

Deforestation in tropical South America

Contains worlds largest continuous tropic forest ad savannah ecosystems. Generates more than a quarter of the worlds river discharge. has undergone explosive development and deforestation in last 50 years ass national and international demand for cattle feed, beef and sugar cane for ethanol have increased. already about 10% of the rainforest in this large region has been covered to cattle pasture and agriculture

Cryospheric water

Cryosphere is those portions of the Earth's surface where water is in solid form (ice)

Hydrocarbon extraction and burning - cement manufacture

Dead plants or animals turn into fossil fuels following burial. pressure from multiple layers of sediment leads to an anoxic (oxygen free) environment that allows for decomposition to take place without oxygen. The type of material that is buried helps to determine what the final product will be. Animal remains tend to form petroleum (crude oil) while plant matter is more likely to form coal and natural gas. When these fossil fuels are extracted from the ground and then burnt, carbon dioxide and water are released into the atmosphere. Cement manufacture contributes carbon dioxide to the atmosphere when calcium carbonate is heated, producing lime and carbon dioxide. Carbon dioxide is also produced by burning the fossil fuels that provide the heat fro the cement manufacture process. Cement industry produces around 5% of global anthropogenic carbon dioxide emissions. The amount of carbon dioxide emitted buy the cement industry is more than 900kg of carbo dioxide for every 1,000kg of cement produced

Carbon in the lithosphere is distributed between these stores:

Marine sediments and sedimentary rocks contain up to 100 million GtC Soil organic matter contains between 1,500 and 1,600 GtC Fossil fuel deposits of coal, oil and gas contain approximately 4,000 GtC Peat which is dead but undefeated organic matter found in boggy areas contains 250 GtC

The lithosphere

Earths lithosphere includes the dust and uppermost mantle. The uppermost part of the lithosphere; the layer that chemically reacts to the atmosphere, hydrosphere and biosphere through the soil forming process is called the pedosphere. Carbon stored in lithosphere organic and inorganic forms. Inorganic - fossil fuels, oil shale and carbonate based sedimentary deposits like limestone. Organic - litter, organic matter, humic substances found in soils

Potential evapotranspiration

Evapotranspiration os closely related to the prevailing temp. The warmer t is, the higher the evapotranspiration. Often havens the temp, and so atmospheres ability to hod water vapour, is greater than amount of water available. Potential evapotranspiration is the amount of water that could be evaporated or transpired from an area if there was sufficient water available

Atmospheric water

Exists as gas, liquid and ice. The most common atmosphere water exists as a gas. This type of atmospheric water os important as it absorbs, reflects and scatters incoming solar radiation, keeping the atmosphere at a temp. that can maintain life. The amount of water vapour that can be held by air depends upon its temp. Cold air cannot hold as much water vapour as warm air. This results in air over the Pikes being quite dry whereas air over the tropics is humid. A small increases in water vapour will lead to an increase in atmospheric temperatures. This becomes positive feedback as a small increase in global temp. would lead to a rise in global water vapour levels, thus further enhancing global warming. Cloud is a visible mass of water droplets or ice crystals suspended in the atmosphere. Cloud formation is the result of air in the lower layers of Earths atmosphere becoming saturated due to either cooling of the air or an increase in water vapour. When the cloud droplets grow they can eventually fall as rain

Percolation

Following infiltration water moves vertically down through soil and unsaturated rock by process of percolation. Can be held in pore spaces in rocks as groundwater. Then passes slowly into zone of saturated rock where it can move vertically and laterally by the process of groundwater flow. Very slow movement. Can feed rivers through long periods of drought. Some rocks able to store lots of water, especially if porous These are called aquifers. Sum of all these movements and stores adds to from the drainage basin hydrological cycle. All flows lead water to nearest river. The river then transfers water by channel flow. Amount of water that leaves drainage basin in this way is called run-off

Water and carbon cycles and the atmosphere

Increased emission of carbon dioxide is warming the atmosphere. This increased temperature results in high evaporation rates and a wetter atmosphere, leads to positive feedback of further warming. Carbon dioxide causes about 20% of Earth's greenhouse effect, water vapour accounts for about 50% and clouds 25%. When carbon dioxide concentrations rise, air temperatures go up. Oceans warm up and more water vapour evaporates into atmosphere, which then amplifies greenhouse heating. There is a time lag between the increase in carbon dioxide and increased warming because the ocean soaks up heat

Carbon sequestration

Involves capturing carbon dioxide from the atmosphere ad putting it into long-term storage, Two primary types: Geologic sequestration and terrestrial or biological Geological sequestration: Carbon dioxide captured at its source (power plant/ industrial process) then injected in liquid form into stores undergo. Could be depleted oil and gas reservoirs or deep ocean. Still at experimental stage. Ocean very capable of absorbing much more additional carbon that terrestrial systems simply because of size. Advantage of ocean carbon sequestration is that the carbon is literally sunk within weeks/months of being captured from air. Once in deep ocean it is in circulation system measured in thousands of years, By the time this carbon reads the seabed it has entered the Earth';s geological cycle. Terrestrial or biologic sequestration: Involves use of plants to capture carbon dioxide from the atmosphere and then to store it as carbon in the stems and roots as well as soil. Aim is to develop a set of land management practices that maximise amount of carbon that remains stored in soil and plant for long term. Also enriches wildlife. Disadvantages of terrestrial sequestration. Forest planted to capture carbon might lose carbon back to air in catastrophic fire or if forest suffers disease or infestation. Slow growing and require active monitoring and management for lifetime of plantation. Carbon within those systems is never removed permanently

Surface water

Is the free-flowing water of rivers as well as the water of ponds and lakes. Rivers - act as both a store and a transfer of water. Transfer water from the ground, from soils and from the atmosphere to a store. That store may be wetlands, lakes or the oceans. Rivers make up a small percent of all water. The Amazon in South America is the largest river by discharge of water in the world Lakes - collections of fresh water found in hollows on the land surface. Generally deemed a lake if bigger than 2 hectares in area. Any smaller is a pond. Largest lake is Caspian sea which is generally fresh water but becomes more saline in the South Wetlands - Ramsar Convention defines as areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing where there is a dominance by vegetation. Wetlands are the main ecosystem in the Arctic These peatlands, rivers, lakes and shallow bays cover nearly 60% of the total surface area. Arctic wetlands store enormous amount of greenhouse gases and are critical for global biodiversity

Main stores of Carbon in the terrestrial biosphere:

Living vegetation - 19% of carbon on Earth. Much of this carbon is stored directly in the tissues of the plants Plant litter - defined as fresh, undecomposed, and easily recognisable plant debris. Leaf tissues account for 70% of litter in forests Soil humus - originates from litter decomposition. Humus is a thick brown or black substance that remains after mist of the organic litter has decomposed. Gets dispersed throughout the soil by organisms e.g. earthworms Peat - this is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands or mires. Peat forms in wetland conditions, where almost permanent water saturation obstructs flows of oxygen from the atmosphere into the ground. This creates low oxygen anaerobic conditions that slow down rates of plant litter decomposition. Covers 3% of land Animals - small part but very important in the generation of movement of carbon through the carbon cycle

Irrigation

Main cause of over-exploitation of groundwater. Example: Greek Argoild plan - boreholes 400m deep contaminated by sea intrusion Example: Italy exploitation of Po River in Milan aquifer has led to 25-40m decrease in groundwater levels over last 80yrs

Affect of sinking water tables

Make rivers less reliable, since many river flows are maintained in the dry season by springs that dry up when water tables fall. Groundwater also helps sustain surface reservoirs (lakes and wetlands) that are highly productive ecosystems and resources for tourists as well as leisure activities

Rate of infiltration

Normally declines during early part of rainstorm event and reaches a constant value after continues rainfall. Number of factors responsible for this: - filling small pores on soil surface with water reduces ability of capillary forces to actively one water into the soil - soil moisten, clay particles absorb water so expand. Expansion reduces size of soil pores - raindrop impact breaks large soil clumps into smaller particles. Particles then clog soil surface pores reducing movement of water

Oceanic water

Oceans cover 72% of the planets surface. They are customarily divided into several principal oceans and smaller seas. Although the oceans contain 97% of Earth's water, oceanographers have stated only 5% has been explored. Oceanic water contains dissolved salts. These salts allow it to stay liquid below 0 degrees C. Oceans are alkaline with average pH of 8.14. The pH has fallen from 8.25 in the last 250 yrs. Change in pH is linked to increased in atmosphere carbon and may have a profound influence on marine ecosystems

Urban Growth

Over half the worlds population now lives in urban areas. Urban population estimated to reach 60% by 2030, with urban areas growing at a rate of 1.3 million people every week. As cities grow, the land use changes form either natural vegetation or agriculture to one which is built up. The carbon dioxide emissions resulting from energy consumption for transport,industry and domestic use, added to the carbon dioxide emitted in the cement manufacture required for all the buildings and infrastructure, have increased. Ij total cities are projected to be responsible for 56% of the global increase in carbon emissions during 2012-2030

Respiration

Plants use stored carbohydrates as an energy source to carry out respiration. Some of carbohydrates remain as biomass. Consumers e.g. animals and bacteria get energy from this excess biomass. Oxygen from the atmosphere is combined with carbohydrates to liberate the stored energy. Water and carbon dioxide are by-products. Photosynthesis and respiration the opposite of each other. Photosynthesis removes carbon dioxide from atmosphere and replaces it with oxygen. Respiration takes oxygen from the atmosphere and replaces it with carbon dioxide. These processes are not in balance. Not all organic matter is oxidised. Some is buried in sedimentary rock. Over geological time,. there has been more oxygen put into the atmosphere and carbon dioxide removed by photosynthesis than the reverse

Photosynthesis

Phytoplankton in sunlit surface waters (euphotic zone) of the oceans turn the carbon into organic matter by the process of photosynthesis. Use energy from sunlight to combine carbon dioxide from the atmosphere with water to form carbohydrates. These carbohydrates store energy. Oxygen is a by-product that is released into the atmosphere

Drainage basin hydrological cycle explained

Te nut into the system is precipitation. Nature, intensity and longevity of the precipitation will have a direct bearing on what happened when the water hits the ground. On a hill slope the following happens: 1. Precipitation lands on bare surface or vegetation. Vegetation provides a store: interception store. Occurring on leaves/branches. Some vegetation is a better interception store than others. Density plays a part. Studies show forest with needle-leaf trees captured 22% of rainfall, while broad-leaf deciduous trees 19%. Difference ay be due to density of the vegetation cover. Some tropical rainforests intercept as much as 58% of rainfall 2. Lots of the water captured by vegetation surfaces is evaporated back into atmosphere 3. Water makes it way from leaves to group by process of through fall from one interception store to another until it reaches ground. Water flows down streams of grasses and in very heavy storms can flow straight down trunks of trees. This is called stem flow 3. Reaches ground water sons into soil by infiltration. Rate of infiltration called infiltration rate. Movement of water into soil is controlled by gravity, capillary action and soil porosity. Soil porosity is sot important. Soils porosity controlled by its texture, structure and organic content. Coarse textured soil have larger pores and fissures than fine-grained soils and therefore allow more water flow. Pores and fissures can be made larger e.g burrowing of worms and penetration of plant roots

Systems frameworks and their application

The Earth is highly complex so geographers have to simply it into models. One type of model is a system. Systems can be classified as: isolated, closed or open Isolated system - no interactions with anything outside system boundary. No input or output of energy or matter e.g. controlled lab experiment very few systems in nature are isolated Closed system - have transfers of energy both into and beyond system boundary but not transfer of matter Open system - matter and energy can be transferred from the system across the boundary into surrounding environment e.g. most ecosystems

Biomass combustion

The boring of living and dead vegetation. including human induced burning s well as naturally occurring fires. Forests have a life cycle : trees die after severe fires, setting stage for new growth to begin. If a forest fully replaces itself there will be no net carbon change over that life cycle. Fire only consumes 10-20% of the carbon and immediately emits it into the atmosphere. it kills trees but doesn't consume them. new trees grow (storing carbon), old trees decompose (emitting carbon) and the organic layer of the soil accumulates (storing carbon). This balance between simultaneous production and decomposition determines whether the forest is a net source or sink. Annually, fires burn 3 to 4 million km2 of the Earth's land surface area, and release more than a billion tonnes of carbon into the atmosphere

Keeling curve

The daily average at Mauna Loa first exceeded 400ppm in 2013. It is currently rising at a rate of approx. 2ppm/year and accelerating

The hydrosphere - oceans

The global ocean data analysis project or GLODAP attempts to measure the amount of Carbon in the oceans. When organisms die their dead cells, shells and other parts sink into deep water. Decay releases Carbon dioxide into this deep water. Some material sinks right to the bottom where it forms layers of Carbon rich sediments. Over millions of years chemical and physical processes may turn these sediments into rocks. This can lock up Carbon for millions of years. It is estimated that this sedimentary rock layer could store up to 100 million GtC

Biological water

The role of animals as a water store is minimal it is plants that are important. Trees take in water via roots and this is either stored in trunk and branches or transported. Water is lost by process called transpiration through stomata in the leaves . Store provides a reservoir of water that helps maintain some climatic environs. If the vegetation is destroyed, this store is lost to the atmosphere and the climate can become more desert-like. Many plants are adapted to store water in large quantities Cacti are able to gather water via extensive root system. The Baobab tree stores water to strengthen the structure

The oceanic stores can be divided into 3:

The surface layer (euphotic zone) where sunlight penetrates so that photosynthesis can take place - 900 GtC The intermediate (twilight zone) and the deep layer of water - 37,000 GtC Living and dissolved organic matter - 730 GtC Total: 40,000 GtC

Water on planet Earth

Water on or close to the Earth's surface is called the hydrosphere. Approximately 97% of hydrospheric water is oceanic. Fresh water makes up the remaining 3% and is locked up in land ice, glaciers and permafrost (cryospheric water), groundwater, lakes, soil, wetland, rivers, biomass (terrestrial water) and atmospheric water. Atmospheric water only makes up 0.4% of all water but has a profound effect on our lives. The amount of water in these stores is in a state of dynamic equilibrium. Changing amounts of atmospheric water in the future could be a major cause or effect of climate change

Groundwater

Water that collect underground in the pore spaces of rock. The depth at which soil pore spaces or fractures and voids ind rock become completely saturated with water is called the water table. Groundwater is recharge and eventually flows to the surface. Natural discharge often occurs at springs and can from wetlands. The amount of groundwater is reducing rapidly due to extensive extraction for use in irrigating agriculture land in dry areas

Weir

Used to measure discharge. Amount of water flowing over the weir is proportional to the depth of the water at the weir. The depth of the water flowing over the weir can be converted into discharge using a simple equation

Vegetation storage

Vegetation requires water to survive. most plants remove water from soil and store it. Called vegetation storage. Plants lose water through stomata in process called transpiration

Ocean warming

Warmer oceans could decrease the abundance of phytoplankton which could limit the oceans ability to take carbon from the atmosphere through the biological carbon pump and lessen the effectiveness of the oceans as a carbon sink. Kills of symbiotic algae which coral needs in order to grow, leading to bleaching and eventual death of reefs

Oceanic carbon pumps

Water is able to dissolve carbon dioxide. Negative correlation between the temp. of water and the amount of carbon dioxide that can be dissolved. This leads to vertical deep mixing. Occurring when warm water in oceanic surface currents is carried from the warm tropics to the cold polar region. Here the water is cooled making it dense enough to sink below the surface layer, sometimes all the way to the ocean bed. When cold water returns to the surface and warms up again, it loses carbon dioxide to the atmosphere. Vertical circulation ensures that carbon dioxide is constantly being exchanged between the ocean and the atmosphere. This vertical circulation also acts as an enormous carbon pump, giving the ocean a lot more carbon than it would have if this surface water has not being constantly replenished. Living things in the ocean move carbon from the atmosphere into surface waters then down into the deeper ocean and eventually into rocks. This action of organisms moving carbon in one direction is often called a biological pump. Carbon gets incorporated into marine organisms as organic matter or structural calcium carbonate. When organisms die, their dead cells, shells, and other parts sink into deep water. Decay releases carbon dioxide into the deep water. Some material sinks right to the bottom, where to forms layers of carbon rich sediments. Chemical and physical processes may turn these sediments into rocks. This part of the carbon cycle can lock up carbon for millions of years

Soil - Amazon

amazonian ails contain 4-9kg of carbon in upper 50cm of soil layer, pasture layer - 1kg. When forests cleared and burned, 30-60% of carbon lost to atmosphere, unburned vegetation decays and is lost within 10 yrs. Soil fungi and bacteria that used to recycle the dead vegetation die off. soils exposed to heavy tropical rainfall. Rapidly washes away topsoil and attacks the deep weathered layer below. Most soil washed into rivers before the forest clearance has caused a reduction in rainfall