The Eden Basin Flashcards
What are some facts about the Eden basin?
The river Eden flows through Cumbria in North-West England in between the Lake District and the Pennines.
It flows into the Irish Sea at the Solway Forth at the Scottish border.
The river is largely rural but it does run through Carlisle.
The upper lengths of the river can experience extreme weather that can result in bad flooding in Carslise made worse by the lower lengths flat terrain.
How do the characteristics of the Eden basin affect the Water cycle?
Rainfall is much above the national average because of the relief of the area resulting in OROGRAPHIC rainfall.
The Eden basin is long and narrow which increases lag time.
The slopes in the basin are steep which increases surface runoff which reduces lag time and increases peak discharge.
Much of the basin is made of limestone which is permeable allowing infiltration and percolation however the upper lengths are impermeable which reduces lag time.
How have changes in the water cycle affected the risk of flooding?
FARMING - between 2000 and 2009 there was a 30% increase in livestock in the Eden valley which are belong to trample and compact soil increasing surface runoff and decreasing surface runoff, this means that rivers rise quicker.
Grazing has also reduced the interception in vegetation.
CONSTRUCTION - Many new homes have been built around Carlisle such as the Eden gate development, this is increasing the amount of impermeable surfaces that is decreasing infiltration and increasing the speed and size of surface runoff leading to more flashy floods.
Many of the new homes have been built on flood plains increasing the flood risk for these homes, so flood defences have been built which is increasing flooding downriver as water would infiltrate on flood plains.
DEFORESTATION - Deforestation has taken place for thousands of years in the basin reducing the interception of rainfall.
CLIMATE CHANGE - Western England can expect up to 35% more rainfall by 2080 because of global warming.
What was the impact of Storm Desmond?
In December 2015 storm Desmond caused the worst flooding ever seen in the Eden basin. In the village of Shap in the basin 262.6mm was recorded in 48 hours which is over 50mm more than the average for the while of December!
More than 2000 properties were flooded in Carlisle alone.
