Hydrology and fluvial geomorphology

Underground water in the drainage basin

water tables, ground water, recharge, and springs.

abrasion/corrasion

when pebbles grind along a rock platform, much like sandpaper

What is the DIRECT human impact on the hydrological cycle

- Altering precipitation entering the drainage basin -Storing water artificially by installing / building dams -Changing channel characteristics which alter the speed of the flow -Transferring water between drainage basins -Abstracting water from the river for industrial, domestic and agricultural use.

Formation of rapids (upper course landform)

- Rapids form at places where the gradient is steep and the river bed is rocky, resistant to erosion, and irregular. - They are usually caused by a band, or bands, of hard rock in the river bed.

What is helicoidal flow

A form of horizontal turbulence - a corkscrewing motion, associated with pools and riffles.

Formation of potholes

A river pothole is a cylindrical, bowl-shaped, or irregular hollow. It is formed in the rocky bed of a stream by either the grinding action of sediment whirled around by stream eddies or the force of fast flowing water. Potholes usually have spirally grooved surfaces.

What is the difference between an annual and storm hydrograph?

A storm hydrograph is over a much shorter period of time

Abstraction

Abstraction is the process of removing water from the river.

Cavitation

Air bubbles trapped in the water get compressed into small spaces like cracks in the river's banks. (EROSION)

What drainage pattern is this?

Annular drainage pattern - Happens when the upload has an outer soft stratum, radial develops subsequent tributaries which try to follow a circular drainage.

Explain how the Kielder transfer scheme has affected natural river flow.

As the Kielder transfer scheme has been positioned, it affects the natural river flow, because more water flow is being put into place in the river channels. This effects the river flow, because the water is always at a certain level in these channels, mostly lowering the water level. Because water has been taken out, the flow is not the same.

Explain how underground aquifers can help to control flooding

Underground Aquifers can help to control flooding, because they take place in filtering out underground water. The process consists of the aquifers separating out the substances, known as filtration. This allows the underground aquifers to help control flooding, because it reduces the amount of water by separating it and then evaporating it. Therefore, reduces the mass of liquid underground, resulting in flood control.

How does global warming influence the hydrological cycle?

Global warming influences the hydrological cycle, because the temperature (as a result from global warming) rises, resulting in an increase of evaporation. This implies that there is a greater amount of water which has been evaporated into the air, causing the hydrological cycle to rapidly speed up as it is forming more clouds with the increase in water. As a result of this, there is an exceeding amount of precipitation, causing more rain and floods.

Straight channel

Upper course landform - develop along the lines of faults and master joints, on steep slopes where rills closely follow the surface gradient, and in some delta outlets.

Building platforms on floodplain - hard or soft engineering

Hard engineering $6,000 or more to elevate floodplains Advantages: -Reduces the risk of flooding -Erosion control -Improved water quality -Recreational opportunities. Disadvantages: -Limits agricultural area for growing crops -Turns soil impermeable= More flood availability as the soil can't infiltrate.

Explain why urban areas receive more precipitation than rural areas.

Urban areas receive more precipitation than rural areas, because due to the increased pollution in urban areas clouds, are more eligible to form causing a greater amount of precipitation. Also, the fact that urban areas have a greater percentage of buildings causes uneven surface winds, therefore, creating more clouds which results in more levels of precipitation.

What drainage pattern is this?

Parallel drainage pattern - pronounced slope to the surface.

How are porosity and permeability related

Porosity and permeability are related properties of any rock or loose sediment. Both are related to the number, size, and connections of openings in the rock.

porosity

Porosity: is a measure of the void spaces in a material.

What are the climactic factors which influence the shape of a peaky flood hydrograph?

Precipitation: High intense / large amounts of rainfall Snow: Fast snow melt Evapotranspiration: Low rates of evapotranspiration outputs. e.g) Winter in Britain

What are the climactic factors which influence the shape of a gentle flood hydrograph?

Precipitation: Low-intensity rainfall, small amounts of rainfall. Snow:Slow snow melt Evapotranspiration: High rates of evapotranspiration outputs. E.g summer in Britain.

What are the flows of a drainage basin system

above ground - throughfall, stemflow, overland flow, and channel flow. below ground - infiltration, percolation (slow movement through soil), throughflow, groundwater, and baseflow.

What drainage pattern is this?

Radial drainage pattern - Usually formed around volcanoes, but can be formed around laccoliths and domes.

What are the upper course landforms?

Rapids Potholes Waterfalls

Dredging - example of hard or soft engineering

Soft engineering $3-$300 per cubic yard Advantages: -Improvement of water quality through restoration of water depth and flow -More spacious, less floods. Disadvantages: -Noise pollution -It can damage or destroy fish spawning grounds and make river banks unstable -Silt can become suspended in the water, lowering oxygen levels, potentially releasing harmful chemicals that may be present.

Afforestation - hard or soft engineering

Soft engineering Depending on the species, the average amount for planting mature trees is around £1,000 Advantages: -Can prevent increased flooding, by reducing surface run off. While it also has an advantage to the water cycle, it also reduces green house gases in the atmosphere, and provides jobs. Disadvantages: -If afforestation is not properly managed, it can result in the loss of habitat and local biodiversity. -Loss of soil and water. Examples: Yorkshire Town: -£500,000 tree planting project helped Yorkshire town miss Winter floods Reduces flood risks by decreasing total runoff and peak river discharge -Tree planting have prevented flooding at pickering in North Yorkshire over Christmas, an analysis of the Snowing flow scheme project published, concludes that measures reduced peak river flow by 15-20% at a time when 50mm of rain fell on sodden ground in 36 hours.

Floodplain zoning - an example of hard or soft engineering

Soft engineering Relatively cheap Advantages : -To avoid building on high risk areas -Helps to avoid damage to property -Creates more green space which creates more agriculture -Increases infiltration Disadvantages : -Puts a restriction on economic development.

What are the soil characteristics which influence the shape of a peaky flood hydrograph?

Soil Moisture: High antecedent soil moisture conditions following prolonged rainfall Permeability: Impermeable soil.

What are the soil characteristics which influence the shape of a gentle flood hydrograph?

Soil moisture: dry soil- the soil store can hold much more water Permeability: permeable soil

What type of hydrograph is this?

Storm hydrograph

What is thalweg

This is the line of fastest flow in a stream and is usually an exaggerated variation of the channel shape that crosses to the outside of each meander at the point of inflection.

How to calculate river discharge

To calculate discharge, multiply the area of water in a channel cross section by the average velocity of water in that cross section. (Area x velocity)

Advantages of the Kielder transfer scheme.

Tourist jobs have been generated. More renewable electricity with the hydroelectric power. Cheap to build to some extent

What drainage pattern is this?

Trellis drainage pattern - Tributaries come together in sharp angles. E.g) The river Ganga.

Bed roughness

calculated using Mannings N The higher the value of N, the rougher the bed.

What are the stores of a drainage basin system

interception, soil water, surface water, ground water, and channel storage.

Equation for the amount of water stored at one point in time

p = q + e +/- s

What drainage pattern is this?

rectangular drainage pattern - When rock structure steers streams into a parallel course, with tributaries joining almost at right angles.

amelioration

the act of making something better; improvement.

Critical deposition velocity

the maximum velocity at which a river can be flowing before a particle of a certain size is deposited

Critical erosion velocity

the minimum velocity needed to erode the load

Solution (erosion)

the process of rock formations, such as limestone, being dissolved in a river setting. (EROSION)

Hydraulic action

the sheer power of the water as it smashes against the river banks. Air becomes trapped in the cracks of the river bank and bed, and causes the rock to break apart. (EROSION)

Stream competence

the size of sedimentary particle that can be transported. Competency may chance as stream volume/flow/velocity change.

What is turbulent flow

the speed of the fluid at a point is continuously undergoing changes in both magnitude and direction. The flow of wind and rivers is generally turbulent in this sense, even if the currents are gentle. The air or water swirls and eddies while its overall bulk moves along a specific direction.

Stream capacity

the total quantity of sediment that a stream can transport.

Solution (transport)

the transport of dissolved chemicals. This varies along the river depending on the presence of soluble rocks. (LOAD OF TRANSPORT)

What is the formation of a waterfall? (upper course landform)

- Waterfalls form where a horizontal layer of hard, more resistant rock (e.g. Whin Sill Dolerite) lies on top of a layer of less resistant rock (e.g. Limestone) in a river valley - The less resistant rock underneath is eroded more quickly - A plunge pool will develop over time as hydraulic action vertically erodes the river bed. This gets deeper as attrition and abrasion further erode the bed - The splashing water and eddy currents in the plunge pool undercut the hard, resistant rock layer above - This creates an unsupported overhang of hard, more resistant rock - The overhang then collapses into the plunge pool - If the process of undercutting and collapse are repeated over a long period, the waterfall will retreat upstream - This is known as a gorge, which is a deep, steep-sided valley

What are the lower course landforms?

-Flood plains -Bluffs -levees -deltas

Saltation

A dancing, hopping, or leaping movement of sediment in the water. (LOAD TRANSPORT)

Graded profile

-Smooth, concave shape -Idea put forward by W.M. Davies -Irregularities in long profile are due to underlying geology -These are eventually worn away and smoothed by the river -Profile of dynamic equilibrium

Dynamic equilibrium

A balance between deposition and erosion

How is a delta formed

1. When a river enters the sea, the hydraulic radius is drastically reduced and the river loses energy. 2. The bottomset beds are formed when material carried in suspension is deposited on the ocean floor. This sediment stretches further out to sea as it is smaller and requires less energy to move. 3. The foreset beds are formed when coarser material transported via traction builds up over time. This sediment is tilted seaward as the delta builds up. 4. The topset beds form on top of the foreset beds and are an extension of the land. These form when the river floods and the alluvium is deposited around distributaries.

Case study on an LEDC flood

Bangladesh 2007 -Hit Bangladesh in June/July & affected 252 villages in 40 districts. This caused millions of people to become homeless. -Destroyed more than two million hectares of crops & vegetation plots. -Bangladesh is a low income country in Asia, over 643,000 people were affected across the country due to the 2007 flood. Human causes: Deforestation- Increasing population in Nepal and Tibet, means that trees were decreased for fuel and grazing land. This resulted in less evapotranspiration, more surface run offs and faster soil erosion, landslides also occured. The river ganges was diverted for irrigation purposes, which removed some of the silt and prevents the floodplain further downstream from being built up. However, caused a flood upstream. Raises capacity of channel increasing the likelihood of a flood Physical causes: Monsoon climate- heavy rainfall and snow. This means that soils are leached and there is a heavy surface run off = soil erosion & rapid increase in river discharge 80% of Bangladesh lies on a huge floodplain and delta. Most of which is only 1m above sea level!! Primary effects: -Around 800,000 metric tonnes lost of crops -643,000 people affected -8.9 hundred thousand livestock damaged Secondary effects: -More than 71,000 houses were lost and 6,500 villages destroyed. -14,294km of roads destroyed Short term responses: -Flood aid from the government of other countries -As Bangladesh is LEDC, relied upon other countries to help -Water purification tablets were put into place -Other countries helped to rescue people -Free seed was given to farmers Long term responses: -Buildings were raised -Around 2,000 flood shelters in Bangladesh. -dams planted -Emergency planning put in place -Countries helped re build 139 embankments -Introduced good warning systems such as The Flood Forecasting and Warning Centre (FFWC) under Bangladesh Water Development Board (BWDB) issues daily flood bulletins and warnings, however, a downside to this is that people who live in remote areas don't benefit as they don't have the correct technology.

Case study of an MEDC flood

Boscastle 2004 floods Background info: 16th August 2004. Flood swept through the small Cornish village of Boscastle. Boscastle is steep and has impermeable rock, located on a confluence of three rivers. 15:51 = flood Caused by the river Valency and Jordan, both of which overflowed, causing a rush of water to speed down the Valency - which runs through the middle of Boscastle. Physical causes of the flood: Impermeable rock, small basin, steep relief, lack of vegetation Human causes: Concrete makes impermeable surfaces, lack of flood control systems with cars getting trapped under bridges & blocking flow of discharge. Primary effects: Roads backed off by flood water. Secondary effects: Flood water damaged a great deal of properties 6 buildings and 75 cars damaged. long term responses: The environment agency is responsible for warning people about the floods & reducing the likelihood of future floods. The agency carried a major project to increase flood defences in Boscastle, with the aim of preventing a similar flood happening again. £4.5 million has been spent on flood defence scheme to help for future floods. River embankments & Boscastle car park has been raised in height, which will stop the river bursting the banks so easily. They also used more permeable surfaces, to help infltrate more precipitation. The only effective response system which took place was the environmnet agency. Short term responses: There was very little time to respond to the flood, as cars were being swept out to sea. No body died, however, there was still a significant amount of damage caused to buildings/cars/roads. The flood defence scheme used hard & soft engineering to help prevent severe outcomes of future floods: -Widening and deepening the river channel - this allowed the river to carry more water. -Removing low bridges and replacing them with wider bridges, this meant large amounts of water could flow freely underneath the bridge and the bridge wouldn't act like a dam (in the 2004 flood, vegetation and debris became blocked, creating the effect of a dam). -Tree management - dead trees were removed to prevent them being swept away, causing blockages under bridges. Land owners were encouraged to maintain vegetation and plant new trees.

Canalisation

Canalisation, the process of introducing weirs and locks to a river so as to secure a defined depth suitable for navigation.

Explain how canalisation affects the hydraulic radius of a river channel

Canalisation, which includes making excess room in a river channel to help flood control, affects the hydraulic radius of a river channel, because it positions tubes which run through the underground, absorbing the water so that there is less water in the actual river channel. This results in reducing the wetted perimeter, therefore, decreasing the velocity of the hydraulic radius

What is centre pivot irrigation

Centre pivot irrigation is when there is a centre point in which a water wheel rotates, causing the land around to be irrigated and watered, by the centre pivot. Example : Libya in Libya centre pivot irrigation can be seen as unsustainable, because they use a significant amount of energy in order to irrigate the surroundings. Additionally, it is also seen as unsustainable, due to the wastage of water. In order for the irrigation to work, there needs to be a lot of water and the majority of it would go to waste, in contrast, to if the farmers would water the areas by hand, there would be a lot less water wastage. Also, the centre pivots require aquifers , which can be seen as unsustainable, because as it is located in the Sahara Desert, little water is going back into the ground for long periods of time, meaning that the centre pivot irrigation is using the majority of the water, rather than the small towns next to it, for example, drinking water.

How to calculate hydraulic radius

Channel cross sectional area / wetted perimeter

What is cloud seeding

Cloud seeding is the process, whereby, an aircraft would be sent further up into the atmosphere with chemical particles that mimic the process of condensation. This then fabricates water droplets, which acts as rainwater.

doing nothing - an example of hard or soft engineering

Costs little money Advantages: -The river is able to flood naturally, not damaging the land. -There won't be a loss of habitat / biodiversity. -The cost is free. Disadvantages: -The government would have to stop building on flood plains/drainage basins. -Can cause severe floods -Limits amount of crops produced.

What is the INDIRECT human impact on the hydrological cycle

Deforestation / afforestation Changing the agricultural land use Urbanisation

What drainage pattern is this?

Dendritic drainage pattern - Most common form, develops in regions underlain by homogeneous material.

What drainage pattern is this?

Deranged drainage pattern - No coherent pattern to the rivers and lakes, can form in areas with extensive limestone deposits, where surface streams can disappear into the groundwater via caves & subterranean drainage routes.

River discharge

Discharge is the volume of water moving down a waterway per unit of time. It is most commonly expressed in Cumecs (cubic metres/second).

What are the drainage basin characteristics which influence the shape of a peaky flood hydrograph?

Drainage density: High drainage density (large number of streams per km) Slopes: Steep slopes Rock type: Impermeable rocks, e.g) clay, crystalline rock. Vegetation cover: Little vegetation cover, lack of interception and root development to open up the soil. Soil depth: Thin soil, e.g) upland areas allow little infiltration. Water stores: Lack of lakes & backwater swamps Urban development: Urban development creates impermeable surfaces and water quickly reaches the channel via storm drains. Agriculture practices: Poor agricultural practices - poor soil structure, trampling by animals

What are the drainage basin characteristics which influence the shape of a gentle flood hydrograph?

Drainage density: Low drainage density (small number of streams per km) Slopes: Gentle slopes Rock type: Permeable rocks e.g chalk and sandstone Vegetation cover: Forest and woodland intercept much rainfall, and root development encourages infiltration. Soil depth: Deeper soils provide a large soil store, - e.g) slope bottoms and lowland areas. Water stores: Lakes and backwater swamps act as water stores and slow the movement to the channel. Urban development: Rural land uses intercept more precipitation and have more permeable land surfaces. Agricultural practices: Good agricultural practices which encourage soil aeration and protect the soil surface.

Negative impacts of building large dams

Extinction of aquatic species - A negative side of building large dams is the effect it has on aquatic species. For example, Dolphins. Dolphins have had a reduced habitat from dams, due to dams interfering with the river flow. For example, the Amazon dam has a significant effect on reducing the amount of dolphins in the rivers. Aids have come together to try and reduce the impact from dams, such as the WWF charity. Losses of forest - Deforestation has been another negative impact from large dams, due to the large dams requiring lots of space to build. Therefore this causes deforestation near/close to the dams. For example, the Amazon basin in the Amazon rainforest. Many dams near here have required more space, so therefore have decreased the size of the Amazon rainforest. Erosion of coastal deltas - Erosion of coastal deltas are a negative impact of building large dams, because dams hold on to the sediment, which in terms doesn't let deltas form as the sediment is being held by the dams. For example, the Nile delta is being reduced, because of the dams taking away the sediment.

Disadvantages of the Kielder transfer scheme.

Families were separated from their homes, due to the building of the kielder transfer scheme. Reduction of fish, this can be due to less breeding as the scheme has disrupted their home, also, this can cause outward migration of the fish. Changes of the environment can also effect the plants, this is due to different environment features, like change in water directions and light.

Positive impacts of building large dams

Flood control - A positive impact of building large dams can be seen as flood control. This means that certain areas which have these large dams positioned near them will be redeemed from significant floods. Dams which are commonly used for flood control are detention dams. For example, the Olmos detention dam in San Antonio, Texas. The Olmos dam consists of six gates which are used to prevent from mass floods. Wildlife - Another positive impact includes the habitation of wildlife. For example, yabbies appear in dams. Yabbies are specifically found on farm dams, which supply water for stock. Yabbies can be seen as a measure for pollution by concentrating Mercury, which is seen as a positive impact on large dams. Hydroelectric power - Hydroelectric power is seen as a positive impact of dams, because it allows the dams to form renewable energy, which then uses this power to decide on which way a current is flowing in a river or other water supply, if kinetic energy is significantly high, the energy will be transformed using systems to then further create electricity. An example of a hydroelectric power system, is China: The three gorges dam. This dam consists of 34 generators. Which allows China to gain a lot of energy from hydroelectric power.

Levees - an example of hard or soft engineering

Hard engineering Advantages : -Provides flood protection without altering buildings nearby. -Levees cause no pressure to damage the buildings -Barriers are usually less expensive than elevating or relocating the structure. -Occupants do not have the areas during construction. Disadvantages : -This technique cannot be used to bring a substantially damaged or improved structure into compliance with floodplain development standards. (Still at risk) -May violate floodplain development standards, particularly in floodway locations, by causing obstructed flow or in increased flood heights. -Failure or overtopping of a levee or floodwall results in as much damage as if there was no protection (or more). -May restrict access to the structure. If human intervention is required for closures, there must be adequate warning time. -May be expensive. -For buildings with basements, hydrostatic pressure from groundwater may still cause damage. -Local drainage can be affected, possibly creating water problems for others. -Interior drainage must be provided. -Levees require considerable land area. Example of levees : The mississippi floodplain - -The levee system, constructed of compacted soil and clay. Mississippi levees currently protect more than 4 million citizens, 1.5 million homes, 33,000 farms, and countless vital transportation routes from destructive floods.

River restoration schemes - hard or soft engineering

Hard engineering Over £7 million, depending on the area Advantages: -Improvements to water quality -Water supply security -Reductions in flood risk & pollution. Disadvantages: -Lacks natural flow -Lacks biodiversity -If nothing done along the river, there are more flood risks. Example: The river Brede - Denmark - -A 5km reach was re-meandered under the EU-LIFE project, but over 15km of the Brede have now been restored as part of a nationwide strategy to improve the environmental management of river valleys. -The scale of re-meandering is much grater than in the UK; the Brede once again sweeps from side to side along the 500m wide floodplain and seasonal flooding has been restored to the whole valley. One unique aspect of this project is the exchange of land between farmers. -The natural regeneration of the meandering river has been rapid and the sea trout are taking advantage of this.

Build embankments

Hard engineering Relatively expensive Advantages: -Limitation of flooding -They increase the cross-sectional area of the river and therefore its hydraulic radius. Disadvantages: -They deprive people of river access for fishing and boating. -They have a higher maintenance cost as they are prone to erosion. -If breached, water will stay on the embankments, destroying the animal habitats. Examples: Bangladesh: -From the 1960s, embankments have been constructed in south western coastal region of Bangladesh to provide protection against flooding, but the success of the polder programme is disputed.

Diversion spillways - hard or soft engineering

Hard engineering Relatively expensive Diversion spillways are artificial channels that divert water overflow when the river discharge, Advantages: -Diversion spillways are channels that divert water away from the river channel, this reduces discharge and the risk of flooding. The water is usually diverted around important areas, protecting them from the consequences of flooding. Disadvantages: -It can cause a risk of flooding at the confluence, which is the junction where two rivers meet and also the river that the diversion spillway is flowing into.

Wetland/riverbank conservation schemes - hard or soft engineering

Hard engineering Around £1,257 Advantages: -Improves water quality -Controls erosion -Enhances habitat -Recreation availability Disadvantages: "If villages are not built with sufficient knowledge, there is a risk of the houses absorbing the humidity in the soil, or even worse, properties being damaged as a result of flooding." -Also, various diseases can be spread in wetlands, such as diseases from mosquitoes.

River straightening - hard or soft engineering

Hard engineering £300-£500 per km Advantages: -Speeds up water (Velocity increases) -Reducing the risk of floods Disadvantages: -Although the water moves more quickly, it doesn't travel as far. - Can increase floods downstream as water moves faster through modified section and increases discharge downstream. -Lacks habitat diversity -Can be relatively expensive and takes a lot of time

Potential energy

In relation to rivers, potential or stored energy is fixed by the altitude of the source of the stream in relation to base level.

Three reasons why water is abstracted from a river channel.

Industrial- Water is abstracted from a river channel for industrial use, because many factories in the primary sector produce chemicals which requires the abstraction of water. Domestic- Water is abstracted from a river channel for domestic use, because of individual household needs. For example, cooking water, drinking water, washing etc.. These factors all require a need for the abstraction of water. Agricultural- Water is abstracted from a river channel for agricultural use, because farmers need to abstract the water to produce / grow crops.

Kinetic energy

Kinetic energy or energy due to movement, is generated by the flow of the river which converts potential energy into moving energy.

What type of erosion happens in lower course landforms?

Lateral erosion

What type of erosion happens in middle course landforms?

Lateral erosion

Suspension

Lighter sediment is suspended (carried) within the water (LOAD OF TRANSPORT)

Braided channel

Lower course landform - Braided streams and rivers have multi-threaded channels that branch and merge to create the characteristic braided pattern.

What are the middle course landforms?

MEANDERS -Pools & riffles -point bars (area after slip off slope where sediment gets deposited) -Ox-bow lakes

Meandering channel

Middle course landform - a single channel that winds snakelike through its valley, so that the distance 'as the stream flows' is greater than 'as the crow flies.'

Kielder transfer scheme.

The Kielder transfer scheme is a system which takes place in North - East England. It takes place in reducing the amount of water which is being held in the Kielder Water reservoir, by depositing this water into nearby rivers. This scheme effects rivers such as Tyne, Tees and Derwent, because when the water is being emptied into these rivers, the rivers remain at the lowest levels when both rainwater is high and low. The Kielder transfer scheme was put into place in April, 1974. However, was accepted in October, 1973.

What is the hjulstrom curve

The curve shows the relationship between the velocity of the river and the size of the particles that can be eroded, transported or deposited. (DEPOSITION & SEDIMENTATION)

Velocity & discharge

The faster the river is travelling and the greater its discharge the more likely the river is to erode.

Entrainment

The process of picking sediment up from the surface and incorporating it into a fluid flow in the water.

What type of erosion happens in upper course landforms?

Vertical erosion

Why do we build dams?

We build dams so that we can reduce many factors such as flooding. The dam is able to hold the water back and store it, so that too much of the water isn't travelling at once. There are also many different types of dams, such as arch dams, diversion dams and many more. Each hold a job, for example, we use arch dams so that the water force can push against the narrow walls, which eventually straightens them up. The arch dam is able to significantly stop floods.

Example of an Isle of Man reservoir that supplies your home address with water

West Baldwin Reservoir

What is an aquifer

a body of permeable rock that can contain or transmit groundwater.

Permeability

a measure of the ability of a material (such as rocks) to transmit fluids.

Traction

a method of transportation for large stones or boulders in a river (rolling) (LOAD TRANSPORT)

What is laminar flow

a type of flow pattern of a fluid in which all the particles are flowing in parallel lines,

What are the outputs of a drainage basin system

evaporation, evapotranspiration and river discharge.

alluvium

gravel, sand, and smaller materials deposited by flowing water

Dams -example of hard or soft engineering

hard engineering More than $50,000 a year Advantages: -Water for drinking/industrial use -Irrigation -Flood Control -Hydro power generation -Navigation -Recreation Disadvantages: -Displacement of people during construction. -Reservoirs often emit a high percentage of greenhouse gases. -Often disrupts local ecosystems.-It disrupts the groundwater table.-Blocks progression of water to other countries, states or regions. Example: Hoover Dam - -Hoover dam was built in 1931. -Hoover dam is in Nevada, USA -For one, it was built in an effort to help control flooding of the Colorado River as it snaked through the southwest on its way to the Gulf of California. Also, as the west opened up and more people settled there, the need for water increased.