Flooding Saturday, 23 February 2019 LO: To identify, describe and explain factors that contribute to flooding

What causes floods? Most floods are caused by heavy rainfall, the rain quickly finds its way into the river. Heavy rain is the main cause of floods however, anything that stops the rain being able to soak into the ground can increase the flood risk. LO: To identify, describe and explain factors that contribute to flooding

Factors that contribute to flooding Tributaries The more a river has, the greater the chance of flooding because of the extra water Soggy soil If there has been a lot of rain lately the soil will be soggy (saturated) so it cannot absorb more rain. Impermeable rock Some areas have impermeable rock just under the soil so the rain can’t soak down. Built up areas Rain can’t soak through concrete, instead rain is taken away by drains and carried quickly to the river. If the drains are blocked streets can flood quickly even if they are not near a river Steep slopes Rain will run down a steep slope quickly – before it has a chance to soak down through the soil The flat flood plain The flood plain is flat land around the river, that the river floods naturally when it gets too full. Deforestation Leaves catch rain (interception) some reaches the ground but the rest evaporates from the leaves Tree roots take up a lot of water from the soil Heavy rain Heavy rain is the main cause of flooding LO: To identify, describe and explain factors that contribute to flooding

What can be done to reduce the effects of flooding? All rivers flood at some time but it’s not always a problem. Look at the image to the right and answer the questions in your workbook. X Y Z LO: To identify, describe and explain factors that contribute to flooding

The last major flood was in July 2007. Evesham in flood With the River Avon running through the town, Evesham is susceptible to flooding. The last major flood was in July 2007. Research this flood and write a short newspaper report in your workbook. LO: To identify, describe and explain factors that contribute to flooding