How water extraction, including surface extraction and sub-surface groundwater extraction (including aquifers and artesian basins) impact the flows and stores in these cycles
- Created by: EmilyM17
- Created on: 22-05-19 08:40
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- How water extraction, including surface extraction and sub-surface groundwater extraction (including aquifers and artesian basins) impact the flows and stores in these cycles
- Surface Extraction
- Reduces levels of channel flow
- Increases sediment deposited
- Dissolved CO2 levels fall
- Water temperatures rise threatening organisms
- Pollutants are less diluted
- Fewer floods reduce the supply of alluvium to floodplain
- Groundwater Extraction
- Reduces water table in aquifers and artesian basins
- Aquifers
- Permeable or porous water bearing-rocks such as chalk and new-red sandstone
- Groundwater is abstracted for public supply from aquifers by wells and boreholes.
- Emerging in springs and seepages, groundwater feeds rivers and makes a major contribution to their base flow
- Upper surface of saturation within an aquifer= the water table. Its height fluctuates seasonally and is affected by periods of exceptional rainfall, droughts and abstraction. Recharge resumes in late April.
- Emerging in springs and seepages, groundwater feeds rivers and makes a major contribution to their base flow
- Groundwater is abstracted for public supply from aquifers by wells and boreholes.
- Permeable or porous water bearing-rocks such as chalk and new-red sandstone
- Artesian basins
- When sedimentary rocks form a basin-like structure, an aquifer confined between impermeable rock layers may contain groundwater which is trapped under artesian pressure
- If this groundwater is tapped by a well or borehole, water will flow up to the surface under its own pressure.= artesian aquifer
- The level of water will rise,- the potentiometric surface- is determined by the height of the water table in areas of recharge on the edges of the basin
- EXAMPLE
- London
- Groundwater from chalk
- London
- EXAMPLE
- The level of water will rise,- the potentiometric surface- is determined by the height of the water table in areas of recharge on the edges of the basin
- If this groundwater is tapped by a well or borehole, water will flow up to the surface under its own pressure.= artesian aquifer
- When sedimentary rocks form a basin-like structure, an aquifer confined between impermeable rock layers may contain groundwater which is trapped under artesian pressure
- Aquifers
- Springs and streams dry up
- Ecosystems are threatened
- Can extract 'fossil' water (water stored underground) for 100s of years faster than it is replenished
- Reduces water table in aquifers and artesian basins
- Surface Extraction
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