Hydrographs show how much water is in a river at any one point at any particular time. All hydrographs have a peak discharge, peak rainfall, lag time, rising limb and a falling (receeding) limb. Every river's hydrograph will be a different shape. The link below shows the main parts of a flood hydrograph:
http://www.bbc.co.uk/schools/gcsebitesize/geography/riverswater/floodingrev3.shtml
Obviously all drainage basins are different. Some are home to huge cities, whilst others are home to hills and forests. Some have permeable rock, some have impermeable rock. Some river's have many tributaries, others few. The point is that because of the geography of the drainage basin, some rivers are more likely to flood than others. This website help to explain why:
http://www.pupilvision.com/yeareleven/hydrograph.htm
No comments:
Post a Comment