洪灾社会经济易损性评估与区划——以渭河下游洪泛区为例

Evaluation of Vulnerability of Social Economy of Flood Disaster

基于渭河下游洪泛区洪灾损失评估和抗洪减灾规划制定的需要,选取人口密度、GDP密度和单位面积年粮食产量作为经济易损性的评价指标,通过影响度赋值和权重叠加,经堤防减灾效益校正后,进行洪灾易损度评估与区划。结果表明,西安市市区南部由于经济相对发达、人口密度较大,且境内南山支流堤防较弱,因而属于洪灾易损度高风险区;西安市市区中部和北部地区、咸阳市市区北部以及临潼区中部地区,由于区域经济发达,且临近的渭河干流部分堤防设防标准较低,因而属于较高风险区;咸阳市市区中部和南部、高陵县、临潼县北部和南部、渭南市市区以及华县西部均属于中等风险区;大荔县东部、华县东部和潼关县由于经济相对欠发达、人口密度相对较低,虽然堤防减洪效益一般,但仍属于低风险区。最后,提出在目前水沙条件没有得到有效控制之前,加强堤防建设、提高堤防减洪效益是降低洪灾社会经济易损度、减少灾害损失的较为有效的途径。

Based on the need of the formulation of losses evaluation and anti-flood and planning of flood disasters in the lower reaches of Weihe River,population density,GDP density and yearly grain output per unit area were chosen in this paper as the evaluation index.By degree evaluation and weighted overlay and after the correction of disaster relief profits,vulnerability of social economy by flood disaster was evaluated and regionalized.The results show that south Xi＇an City belonged to the highest risk zones because of the developed economy,higher population density and weak levee.Middle and north Xi＇an City,North Xianyang City and middle Lintong were in the higher risk zones.Middle and south Xianyang,Gaoling,north and south Lintong,Weinan City and west Huaxian were in the middle risk zones.East Dali,east Huaxian and Tongguan were in the lower risk zones for the underdeveloped economy,lower population density.Finally,it was put forward that under current situation,strengthening levee to enhance efficiency of disaster reduction of levee was an effective way to reduce the degree of vulnerability of social economy and loss of flood disaster.