How can relief increase flood risk?

Relief can increase flood risk because:

  • Steep sided slopes mean that it is hard for infiltration to occur which leads to greater surface run-off
  • Low lying flood plains are at risk of flooding because they do not have enough gradient to move the water on quick enough. This risk increases when the soils have a high clay content.
  • Upland areas are more likely to experience rain due to relief rainfall. This increases the likelihood of high levels of precipitation and therefore surface run-off.

Find out more about human and physical causes of flooding.