1. What are the causes and consquences of flooding?

2. What are the causes of floods? What is a flood? When do rivers flood? What factors cause flooding? Flooding in Boscastle case studyFlooding in Boscastle case study What were the causes of the Boscastle flood? Homework: what were the consequences of the Boscastle flood? 2004

3. Boscastle Flood 2004: Flood factors Higher than average rainfall, more rain in one day than normally falls in a month Human activity: tarmac’d car park increased surface runoff Relief: steep sided valley Pre-existing conditions: ground saturated by previous rainfall Drainage density: small drainage basin, two rivers (Valency and Jordan) converge, narrow drainage basin, rivers meet in centre of village High tide: prevented water leaving the rivers Soil type: prob. Porous as saturated and collapsed - landslide

4. Where will it flood? Are areas flood prone? Environment Agency flood map Rates an area’s risk to flooding Includes areas that are defended

5. Impacts of flooding Remember the risk equation? Risk = hazard exposure + vulnerability - management

6. Why do the impacts of flooding differ? Contrast the impacts of flooding in the UK [Severn and Thames] and SE Asia [Ganges] August 2007