Friday, July 19, 2019

Floods of 1998 in Bangladesh and Shrewsbury :: Papers

Floods of 1998 in Bangladesh and Shrewsbury Causes, Effects and responses to flooding In Shrewsbury The Severn Valley floods, Shrewsbury, UK 1998: Causes ====== The human causes of the floods were summed up by the then Shadow Countryside Minister Tim Yeo MP, he said 'the flooding had increased because of the housing developments on Greenfield sites.' By this he means that by covering the land with tarmac in urban areas humans have increased the rate of surface runoff and decreased the saturation levels of the ground. When surface runoff is high rainwater reaches the river faster. It would appear that the speed in which the water reached the river was too fast for the river to handle. The river filled up reaching bank-full discharge and then overflowing its banks onto the flood plain. The flood plain of the River Severn is built on, therefore, when the river floods it floods onto residential areas. With the building of these urban areas the amount of vegetation in the area surrounding the river was reduced, this affects the river two ways. It reduces the amount of interception, which in turn increases the speed of runoff into the river. The lack of vegetation also leads to the saturation of the ground. During the months of October and November the rainfall in the Severn Valley was high, as the water soaked into the ground it became saturated. More vegetation in the area would have meant the vegetation using the water would have decreased the amount of water in ground storage. Physical factors of the flood in 1998 are many; however, the most important one was the amount of rainfall. In October 1998 many areas received record amounts of rainfall caused by a 'hurricane'. This 'hurricane' brought very heavy rain and strong winds. The fact the rain was heavy means that the river did not have time to dissipate the water quick enough and the runoff was too fast, making the river rise t such an extent that it flooded.

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