Eden Basin Flashcards
(14 cards)
Where is the Eden drainage basin
In north-west England, between the mountains of the Lake District and the Pennines
the river drains in the north-east lake district fells and the north-west Pennines
Where is the river Eden’s source
In the Pennine hills in south Cumbria
It flows north-west through Appleby-in-Westmorland and Carlisle. Its mouth is in the Solway Firth at the Scottish border
Is the river basin rural
It is largely rural, although the River Eden does flow through Carlisle
What is the weather like in the upland areas that drain into the River Eden
They experience extreme weather that can cause flooding downstream
Carlisle is particularly vulnerable as it’s at the confluence of the Eden, Petteril and Caldew rivers, and is fairly low-lying
How do characteristics of the Eden Basin affect the Water cycle
-Higher rainfall than national average - relief, mountainous terrain - orographic rainfall. High rainfall means that lots of water enters the river channels
- The Eden Basin is long and relatively narrow, which increases lag time
- The slopes within the basin are steep. This reduces lag time and increases peak discharge
-rock types
What is rainfall like in the Eden Basin
Rainfall is higher than the national average because of the relief of the area - the mountainous terrain encourages orographic rainfall
What are the rock types like in the Eden Basin
- The highest ground, to the west of the basin is made of igneous rocks, which are impermeable. infiltration is very slow and surface runoff is high in these areas, reducing lag time
- Much of the basin, however is made up of limestone and sandstone, which are permeable. When precipitation falls in these areas, infiltration is quick and there is little surface runoff, increasing lag time. the amount of water in ground stores increases
How has farming affected the risk of flooding in the Eden Basin
-more intense farming has caused soils to become compacted, e.g. by heavy machinery or trampling by livestock. Between 2000 and 2009, there was a 30% increase in the number of cattle in the Eden Valley, much more land is likely to have been trampled. Compaction of soils reduces infiltration, so surface runoff is higher. This means water levels in rivers rise quickly during heavy rainfall, increasing the risk of flooding
-Grazing in upland areas, e.g. hill farming of sheep, has also reduced the amount of vegetation that can intercept rainfall, resulting in more water reaching rivers
How has the number of cattle in the Eden Valley changed
Between 2000 and 2009, there was a 30% increase in the number of cattle in the Eden Valley
How has construction affected the risk of flooding in the Eden Basin
-although the majority of the Eden Basin is rural, built-up areas have increased. Many new housing estates have been built in and around Carlisle in recent years, e.g. the Eden Gate development to the north of the city, and there are plans to develop a huge ‘garden village’ to the south of the city, including up to 10,000 new homes
-Surfaces in built-up areas tend to be impermeable, reduces the size of infiltration flows and greatly increases the size and speed of surface runoff flows
-Some new developments, particularly near Carlisle, have been built on floodplains. This has created a flood risk to property and has required the construction of flood defences to protect homes. Building on floodplains can cause flooding downstream as water that would naturally infiltrate on the floodplains flows downstream instead
How has deforestation affected the flood risk in the Eden Basin
- Deforestation has taken place in the basin for thousands of years, e.g to provide timber, and land for farming. Much of the original forest cover in the Eden Basin has now been removed, giving way to large areas of open grassland and heathland
-Trees increase infiltration and decrease runoff, so fewer trees means more runoff, flashier flood hydrographs and a greater risk of flooding
When was storm Desmond
In December 2015, Storm Desmond caused devastating flooding in cumbria. some of the worst flooding occurred in the Eden Basin
What was rainfall like in cumbria as a result of storm Desmond
In some areas of cumbria, there was record rainfall.
-In Shap, a village in the eden basin, 262.6mm of rain fell in 48 hours between the 4th and 6th of December. that’s nearly 50mm more than the average rainfall for the whole of December
How were Appleby-in-Westmorland and Carlisle affected
More than 2000 properties were flooded in Carlisle alone, leaving many people homeless
