土地利用变化驱动下的上海市区水灾灾情模拟

Simulation of flood disaster scenario under driving action of land use change in urb of Shanghai

对上海市区近50年来的土地利用结构变化进行了重建,并计算了由土地利用变化引起的上海市区水位变化量。以特定的1962年水灾为参照,模拟在同等雨强情况下,由土地利用结构变化和地面沉降引起的淹没范围的变化以及由此带来的水灾损失的变化。结果表明,在49mm/d降水条件下,由于土地利用的变化,使2001年的径流系数比1950年增大了34.0％,2001年的水位比1950年增高了45.9％;2001年的水灾灾情为1950年的1.0629倍;即使在目前千年一遇的防洪标准下,亦可造成相当于2001年地均GDP值0.088％(约为4.5亿元人民币)的损失,这是1991年相应数值的220倍。

In this paper the changes of land use structure in recent 50 years and evolvement of water level driven by changes of land use in the urban area of Shanghai was reestablished. Referring to a certain flood in 1962, the change of inundated area induced by land use structure change and ground subsidence,and the relevant change of flood loss under same rainfall intensity as in 1962 were simulated. Result shows that on the condition of a daily rainfall of 49mm, owing to the changes of land use, in 2001 the runoff coefficient and water level have arisen by 34. 0% and 45. 9% respectively, and the flood disaster has increased 1. 0629 times from 1950. These figures mean that even under the protection of the flood control standard of flood frequency 0. 1% at present, a loss equivalent to 0. 088% of GDP of the city in 2001 (about 0. 45 billion RMB) would be caused, which is about 220 times of the responding value in 1991.