江苏省洪涝灾情及风险的时空分析

Spatio-Temporal Analysis of Flood Impacts and Risk in Jiangsu Province

采用灰色关联分析,计算全省各市2011-2017年洪涝灾情指数;运用熵权法估算洪涝风险指标权重,评估各市2005-2018年综合洪涝风险。主要结果表明:选取的灾情指标能有效地反映区域洪涝灾情,扬州是全省历史灾情较为严重的城市,全省大部分城市在2012年和2015年的灾情指数较高,2016年苏南和苏中的灾情较严重;各市在2014年之前洪灾风险较小,波动也较小,而2014年之后风险增加.显著,主要由降水因素变化导致;相对高风险区在空间上呈现由北向南,由海向内陆转移的趋势。

This study calculated the comprehensive flood impact indexes of each city in Jiangsu Province from 2011 to 2017 through grey correlation analysis,and assessed the comprehensive flood risk by using the entropy method to determine each index weight from 2005 to 2018.The results show that:(1)The considered indicators can effectively reflect the regional flood impact.Yangzhou is the most severely affected city.Most cities have high values of the disaster index in 2012 and 2015.In 2016,disaster situations are severe in the southern and central areas.(2)The risk value and the corresponding fluctuation range were both low for all cities before 2014,while the risk increased significantly after 2014 which was mainly led by the precipitation change.The relatively high-risk areas show a trend of shifting from north to south and from sea to inland in space.