Water Extraction Flashcards
How is water extracted to meet public industrial and agricultural demand?
Water is extracted from surface and groundwater.
What happens when there is direct human intervention in the water cycle?
Direct human intervention in the water cycle changes the dynamics of river flow and groundwater storage.
Which area does the River Kennet in southern England drain?
The River Kennet in southern England drains an area of around 1200 km² in Wiltshire and Berkshire.
What type of rock is predominant in the upper catchment of the River Kennet?
The upper catchment of the River Kennet mainly comprises chalk, which is highly permeable.
What contributes most to the flow of the River Kennet?
Groundwater contributes most of the Kennet’s flow.
What are some characteristics of the water in the River Kennet?
The water in the River Kennet, filtered through the chalk, has exceptional clarity, high oxygen levels, and is fast-flowing.
Which urban areas rely on water from the Kennet basin for public supply?
Several urban areas within and close to the catchment rely on water from the Kennet basin for public supply.
What is the population of Swindon, the largest urban area relying on water from the Kennet basin?
Swindon, the largest urban area relying on water from the Kennet basin, has a population of over 200,000.
How does Thames Water extract groundwater from the upper catchment?
Thames Water abstracts groundwater from the upper catchment of the Kennet through boreholes.
What has been the impact of water extraction from the Kennet and its catchment?
Water extraction from the Kennet and its catchment has led to a reduction in flows in the River Kennet by 10-14%, and even up to 40% during dry conditions in the early 1990s. It has also reduced flooding, standing water, wetlands on the floodplain, and the occurrence of springs and seepages.
What are aquifers?
Aquifers are permeable or porous water-bearing rocks such as chalk and New Red Sandstone.
How is groundwater abstracted for public supply from aquifers?
Groundwater is abstracted for public supply from aquifers through wells and boreholes.
What is the upper surface of saturation in an aquifer called?
The upper surface of saturation in an aquifer is known as the water table.
What factors affect the fluctuation of the water table?
The water table fluctuates seasonally and is affected by periods of exceptional rainfall, drought, and abstraction.
When does the water table typically fall and rise in southern England?
In normal years in southern England, the water table falls between March and September due to rising temperatures and increased evapotranspiration losses. Recharge typically resumes in the late autumn.