Case Study A: River Parrett

Question 1

List the human causes of flooding.

Answer 1

1. Building on floodplains- Building on floodplains increases the impermeable surfaces which reduces infiltration and throughflow while increasing surface runoff. Drains and gutters remove the water but increase the risk of flash floods.
2. Destroying the natural environment- Deforestation means there’s no interception or uptake of water from the soil meaning saturated soil, impermeable soil and increased surface runoff.
3. Farming practices- Hedges have been reduced to make farming more efficient but this decreases interception. Moreover fields are ploughed, creating a channel for water and sediment to flow down it.

Question 2

Explain the physical causes for the flooding of the Somerset Levels.

Answer 2

• Low lying farmland- area forms the floodplain of the River Parrett and is surrounded by hills.
• Between December 2013 and February 2014 14 major storms occurred which led to saturated soil.

Question 3

Explain the human causes for the flooding of the Somerset Levels.

Answer 3

• River full of silt- hadn’t been dredged in 20 years therefore couldn’t hold all the water.
• Houses were built in nearby towns on floodplains. The water was pumped away and extra water was sent to the Somerset Levels. Impermeable surfaces caused water to arrive quickly to the river.
• Changing in farming practices in hills. The fields converted from grassland to maize meaning the land was used more, meaning the soil could retain less water, leading to more surface runoff.