(Original post by ThatGirlx)
Does anyone know how flooding may be caused by human factors or physical factors?!
Our teacher never even said anything about flooding but now I see on the spec you need to know about flooding too ..
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If a 15 marker comes up on this:
Measuring physical factors:
1) Surface runoff - The amount and speed of surface runoff affects the risk of flooding because the sooner precipitation reaches the river the more chance there is of the level rising above the bankfull discharge.
Surface runoff can be measured directly by digging a ditch of a known ares and using a container to collect runoff. You then need to divide the runoff collected by the rainfall at each location so you can compare locations fairly.
2) Infiltration - A high infiltration rate reduces surface runoff and vice versa (as stated on previous posts) It can be measured by using an 'infiltration ring' That you push into the soil. Then you pour a known volume of water and time how long the water takes to soak away
3) Vegetation cover - The mroe vegetation cover there is. The more interception (Vice versa) - You can map the vegetation cover of an area of land to find how much vegetation there is and to see if there's gonna be more interception etc then base your results on that. (Make it up)
Land use can be mapped to record the amount of urbanisation. Agricultural land. Deforestation. This can be then combined with research to investigate the links between precipitation and flooding.
Ordnance survey maps to find the size and gradient of river drainage basins.
Look at maps on British Geological Survey to see different types of rocks in different areas
Use masp (google maps. Google.co.uk) To see links between vegetation and flooding.
Research for land use: Historical maps, land use surveys, old photographs, historical diares. These sources show how land use has changed over time etc.
Flood risk maps on the environment agency website. The maps shows areas which are at risk from flooding and which areas benefit from flood defences/barriers.
Hope this summed up everything. I know it's a bit straightforward and a bit rushed but this is pretty much what you need to know. You'll be fine x
If you're unfamiliar with some keywords. Here they are:
Discharge - The amount of water that flows in a river per second
Evapotranspiration - The combination of evaporation and transpiration
Infiltration - Water soaking into the soil
Interception - When precipitation lands onto vegetation or other structures before it reaches the soil
Lag time - Delay between peak rainfall and peak discharge
Surface runoff - Water flowing over the ground