Flooding Flashcards
Food management strategies (defences)
mitigation strategies
Barriers and walls around the river - blocks water when floods but if closed too late they are useless
Raise and extend old flood walls - in places likes Melbourne park - improves quality and effectiveness old prior defences without needing to take a long time to build new ones - stops rivers from flooding at all
students at Newton Rigg agriculture college students rebuild farmers walls as part of their course - invests in repairing traditional flood walls that are around farm lands and fields - cost effective and reduces risk of flooding destroying crops and locals livelihoods
river restoration - allow rivers to keep their meanders and provide space for them to keep the bends - Reduces speed of flow, supports biodiversity - reduces land use specially in cities with lots of rivers such as carlisle
flood warnings - Alerts sent to residents via text, email, or radio - event thing over past decade by EA - Gives time to prepare or evacuate - People may ignore warnings, tech issues
afforestation - Planting trees in river catchments - upland Cumbria - Increases infiltration, slows runoff - Takes time to grow, limited space
Flooding causes
(manmade and human)
Manmade changes to rivers means floodplains are often altered too and local wildlife becomes flat and managed - in rare case that the managed area becomes flooded the floodplains are void of vegetation and no natural barrier to slow flood of water - water travels into nearby fields and populated areas quickly
Building houses and roads of floodplains close to rivers is common by the council - Floodplains act like sponges and temporarily store rain and river water during floods by building on them the water has no where to go so it has to stay in the river - as a result the river channel rises higher and floods faster than it would have originally
Blocked flow paths due to buildings and roads obstructs the rivers natural flow and direction of water - this redirects/blocks it causing the river to back up and flood in locations where it wouldn’t usually - means that area that’s unprepared is heavily effected causing more casualties and damage
Rapid melting of snow in upland areas (like the Lake District) causes a sudden increase in river discharge. - Common in late winter/early spring when temperatures rise quickly and is often unpredictable - snowmelt combined with heavy rain increases surface run off and worsens the flooding
steep relief adds to flooding as when it floods downhill the terain giving it less time to infiltrate into the ground - The Lake District and Cumbria have steep upland areas, which speed up water flow into river valleys. - the water becomes quicker flowing and more dangerous against buildings - also more dangerous for firefighters to evacuate people
responses to flooding
Manmade changes to embankments by changing meanders into straight rivers like a ‘pipe’ - cause of this the water travels quicker and less likely to slow down and flood surrounding area - keeps natural beauty of area and protects surrounding floodplains
After flood in 2015 firefighters where educated on how to handle floods and received equipment’s such as inflatable boats to keep handy which didn’t have before - Means firefighters can reduce casualties and respond quicker to emergencies and evacuations
Upgraded flood warning systems were implemented by the Environment Agency (EA) - warns people that are signed up with the app when a flood might happen in advanced - reduce loss of life and property damage by giving people time to act. also, supports better emergency service coordination - less effective if the weather is drastic and quick changing
In rural areas upstream (e.g. Cumbria), they began using soft engineering like planting more trees and rewilding - not only does it create and support habitats but increase infiltration and reduce surface runoff - stops water from traveling as far and as quickly
After storm Desmond in 2015 the government supplied grants to home/business owners to install their own flood defences - If people do not add enough quick enough these defences won’t work - cost effective to give money to everyone
fixing leaky dams - reduces peak flow downstream -holds millions of litres of water but very cost effective and difficult to upkeep
