Eden Basin - Case Study

Question 1

Describe the background information on the Eden Basin. Location etc

Answer 1

• NW England between Lake District and Pennines
• Mainly rural
• Upland areas that drain to Eden experience severe weather, can cause flooding

Question 2

Describe the water cycle in the Eden Basin.

Answer 2

1. Rainfall higher than average due to mountainous terrain = orographic rainfall
2. Eden Basin = long + narrow, increases lag time
3. Steep slope, reduces lag time + increases peak discharge

Question 3

Describe the structure of the Eden Basin

Answer 3

• West of basin = impermeable igneous rocks - low infiltration, high runoff, reduced lag time
• Most of basin = permeable lime+sandstone = permeable = more infiltration less runoff, higher lag time

Question 4

What 3 things have changed the water cycle in Eden?

Answer 4

Farming, construction, deforestation

Question 5

How has farming affected the water cycle in the Eden Basin?

Answer 5

1. Intense farming has compacted soil - livestock + heavy machinery
   - Between 2000 -> 2009, 30% increase in cattle in Eden Valley
2. Compaction reduces infiltration = more runoff = river levels rise quickly in heavy rainfall = higher flood risk
3. Upland sheep grazing has reduced vegetation = less interception = more runoff

Question 6

How has construction affected the water cycle in the Eden Basin?

Answer 6

1. New housing estates - Eden Gate development - houses built north + plans to build 10,000 houses south
2. These areas have lots of impermeable surface = less infiltration = more runoff
3. New developments in Carlisle built on floodplains = increased flood risk so defences were built.
   - Building on floodplains causes flooding downstream

Question 7

How has deforestation affected the water cycle in the Eden Basin?

Answer 7

1. Deforestation for timber + farming has cleared most of Eden’s forests
   - More trees = more interception = less runoff, fewer = flashier hydrographs

Question 8

When did Storm Desmond occur? What effects did it have?

Answer 8

December 2015, flooding in Cumbria

• Shap, 260mm of rainfall fell in 48 hours 4th -> 6th December (50mm above December rainfall average)
• Carlise, 2000 properties flooded, homeless