river exe Flashcards
(25 cards)
What is the location of the River Exe?
- flows through Exmoor National Park
- southwestern England
- enters the English Channel.
What is the length of the River Exe?
82 kilometers long.
What is the average annual rainfall in the River Exe catchment area?
around 1,200 mm of rainfall annually.
How does the soil in the River Exe influence the water cycle?
Soil, particularly in peat bogs, helps store water, impacting infiltration and soil moisture.
How does the River Exe contribute to the carbon cycle?
- carbon absorption by vegetation
- storage in soil
- transport of organic carbon downstream.
What role do peat bogs play in the carbon cycle of the River Exe?
Peat bogs store large amounts of carbon, but disturbance can release this stored carbon.
How do human activities affect the carbon cycle in the River Exe?
Deforestation, agriculture, and urbanization reduce carbon storage and increase emissions.
What are the main carbon fluxes in the River Exe?
- Photosynthesis (carbon uptake)
- respiration (carbon release)
- decomposition (carbon release)
How does climate change affect the water cycle in the River Exe?
may increase rainfall, leading to more runoff and flooding, altering evapotranspiration.
How do wetlands impact the carbon cycle in the River Exe
Wetlands act as carbon sinks, storing carbon in vegetation and soil, and influencing the water cycle by filtering water.
What are the key management strategies for the River Exe?
- flood risk management
- sustainable land use practices
- conservation of wetlands and peat bogs
How does flood management work along the River Exe?
Flood defenses:
- floodplain zoning
- River channel modification
- flood- warning systems
How does agricultural management help protect the River Exe?
- reduced use of fertilizers,
- buffer zones
- erosion control
-help minimize pollution and runoff into the river.
What role do wetlands play in the management of the River Exe?
- natural flood defenses, absorbing water during heavy rainfall
- provide habitats for wildlife
- help regulate water quality and store carbon.
How much carbon do Exmoor’s peat bogs store?
approximately 3 million tonnes of carbon.
How much funding was allocated for flood risk management along the River Exe in 2020?
The UK government allocated £4.7 million
how does topography influence runoff?
steep upland areas such as Exmoor, leads to rapid surface runoff
How does geology affect infiltration and runoff in the River Exe basin?
Around 84% of the River Exe catchment is underlain by impermeable sandstone, which leads to reduced infiltration
How does land use in the River Exe basin impact the drainage system?
- predominantly agricultural (67%) with some woodland (15%)
- grazing compacts soil, reducing infiltration and increasing surface flow.
What is the impact of the Wimbleball Reservoir on the River Exe’s hydrology?
- 1979
- holds 21 billion litres of water and regulates flow by reducing peaks and maintaining steady discharge during dry periods
- helping manage flood risk downstream.
What is the Exmoor Mires Project and how does it impact the River Exe?
- Since 2010, over 1000 hectares of Exmoor’s peatland have been restored to increase water retention
- enhances infiltration, slowing down the flow into the river and improving water quality.
What are the key outputs from the River Exe drainage basin?
- Evapotranspiration and streamflow (river discharge) are the major outputs
How does vegetation influence outputs in the River Exe basin?
- Areas with woodland and moorland increase interception and evapotranspiration
- grazing land reduces vegetation cover and leads to greater runoff
How does drainage of peatlands affect the carbon cycle?
Draining peat exposes it to oxygen, accelerating decomposition and releasing CO₂, converting it from a sink to a source
