江淮分水岭地区旱涝灾害致灾气候阈值分析

The Threshold of Drought and Flood Disaster in Drainage Divide Area between Yangzi River and Huaihe River

采用江淮分水岭及周边地区1960—2010年14个气象站点的逐日降水量数据,运用涝灾阈值法和SPI指数(标准化降水指数)法,确定了旱涝灾害致灾气候阈值,分析了不同等级旱涝灾害时空分布特征,同时结合1989—2010年区域农作物受灾情况,进一步探究了致灾气候阈值与农作物受灾面积之间的关系。采用1960—2010年降水量数据计算得到了江淮分水岭地区5级涝灾致灾气候阈值,通过SPI指数确定了旱灾致灾气候阈值。对比分析结果显示,典型旱、涝灾年份旱、涝灾空间分布情况与实际情况较为吻合,说明两种旱涝阈值方法都适用于江淮分水岭地区旱涝灾害分析。进一步通过构建致灾气候阈值与农作物受灾面积之间的关系模型,发现旱灾致灾气候阈值与实际旱灾受灾面积之间存在着较高的相关性,而涝灾致灾气候阈值与涝灾受灾面积之间相关性相对较小。

Based on the daily precipitation at 14 stations in the drainage divide and the surrounding area between Yangzi River and Huaihe River during 1960 to 2010,the thresholds of drought and flood disaster were calculated and the spatial and temporal distribution of the disasters was analyzed by using flood threshold method and SPI. The relationship between the thresholds and crops affected areas was further studied based on crop damaged induced by floods and droughts during 1989 to 2010. It identified the thresholds of flood disaster at class 5 in the study region based on precipitations,and the thresholds of drought based on SPI. The result shows that the spatial distribution of flood and drought is consistent with the reality,deducing the thresholds and SPI methods are appropriate for the study region. This study also built a relation model between threshold of drought and flood disaster and crops affected area. It is found that the threshold and crops affected area is highly correlated for drought while are low correlated for floods.