The River Eden Flashcards
(9 cards)
Location?
- Eden basin is located in North West England between lakes and Pennines
- Source is located in the Pennine hills in south Cumbria
- Flows north west through Appleby and Carlisle with mouth in Solway Firth
- Largely rural basin besides urban areas such as Carlisle
Characteristics?
- located at confluence of the Eden, Calder and Petteril
- rainfall is higher than national avg due to orographic rainfall (2800mm upland)
- long narrow basin increases lag time
- steep reliefs within basin decrease lag time and increase peak discharge
- high ground has impermeable igneous geology so less infiltration and more run off
- low ground has permeable geology so more infiltration and less run off (saturated large ground water store) sandstone
Anthropogenic changes to the water cycle?
FARMING- soil is compacted by machinery or livestock. 30% increase in cattle from 2000-2009 in the Eden valley incareses compaction and grazing so less interception, more run off, less infiltration etc.
CONSTRUCTION- new housing estates built which increases the area of impermeable surfaces e.g. 10,000 houses built as a part of the Eden Gate and Garden Village projects. New properties built on a floodplain so flood defences built which worsen flooding downstream
DEFORESTATION- only 10% of their basin is vegetated due to clearance for agriculture
CLIMATE CHANGE- climate change could increase rainfall by 35% by 2080 which increases flood risk
other developments- applyby football club is land zoned with 6 inch floodgates to hold water during flooding, warcorp mod firing range has tanks that compacted 24,000 acres of land
Physical causes of the 2005 Carlisle flood?
- late December 2024 had 2 weeks of heavy rainfall (between 6th and 8th 15% of annual rainfall fell in 36 hours)
- storm force winds of 90mph felled trees which blocked rivers and drains
- river reached a peak discharge of 1500 cumecs compared to the average 51 m3/s
Human causes of Carlisle flood 2005?
- inadequate flood defences as waters were 1m above the flood defences which withstood 1048 cumecs.
- urbanisation of flood planes increased impermeable surface area
Short term impacts?
- 3 people died
- 6000 people rehoused
- 1600 homes flooded costing £100 million
- 70,000 had no power
- industrial estates such as rose hill flooded which damaged 325 business properties
- 1,150 trees felled so loss of habitat
Long term impacts?
- reappraisal of flood defences to last 3 years and cost £20 million
- intangible social effects e.g, suicide by uninsured homeowner
- small businesses went bankrupt
- a year later some families still in temporary housing
Flood management techniques?
- 50km of new flood embankments built to increase river capacity
- dams implemented upstream to slow water
- dredging of channel to increase river capacity
- 500,000 sand bags made available
2015 floods?
Flooded again in 2015 due to 262mm of rainfall in 48 hours which flooded 2000 properties, suggesting flood defences still were not effective.
