1961-2010年长江中下游地区农业洪涝灾害时空变化

为揭示长江中下游地区农业洪涝灾害的发生、分布及时空演变特征,基于1961-2010年研究区内426个气象站点的逐日降水数据,以湖北省单站洪涝等级标准为初始指标,对该指标临界值在-50~100 mm范围内进行同步增减,结合该区7省（市）的洪涝历史灾情记载和农业洪涝受灾面积,采用逐步剔除的方法筛选指标,构建分省农业洪涝等级指标并验证指标的合理性,分析该区近50年农业洪涝灾害的时空变化。结果表明：① 近50年长江中下游地区的农业洪涝灾害发生总体呈增加的趋势,但不同区域和不同年代际差异明显;② 20世纪60年代至80年代农业洪涝发生次数相对平稳,90年代洪涝明显增多,21世纪初洪涝又相对减少;③ 区域农业洪涝灾害明显呈现出江南多、江北少的分布特征。农业洪涝多发区主要集中在江西中北部、江汉平原、浙江沿海,以及安徽、江西和浙江三省交界地带。

The temporal and spatial variations of agricultural flood disaster over the middle and lower reaches of the Yangtze River from 1961 to 2010

To understand the occurrence, distribution and temporal-spatial variation of agricultural flood disaster in the middle and lower reaches of the Yangtze River, based on the daily precipitation dataset of 426 meteorological stations in this area from1961 to 2010, the single station flood indicator was built. The flood level standards of single station in Hubei Province were selected as an initial indicator. Then the threshold of precipitation in the process increased or decreased in a range from -50 to 100 mm. Flood indicator was gradually selected by combining with historical flood records and agricultural areas suffered from flood disaster. The provincial agricultural flood indicator was built and its rationality was further verified. The temporal and spatial changes of agricultural flood disaster in the area for nearly 50 years were analyzed. The main results are as follows: (1) The occurrence of agricultural flood in the middle and lower reaches of the Yangtze River has increased in recent 50 years, and regional and decadal differences are obvious. (2) Less agricultural flood occurred during the 1960s-1980s, and significantly increased in the 1990s, and then decreased since the beginning of the 21st century. (3) There were more occurrences of agricultural flood in the region south of the Yangtze River than in the regions north of it. The areas in which agricultural flood occurred most were the central and northern parts of Jiangxi, Jianghan plain, Zhejiang coastal areas, and the junction of Anhui, Jiangxi and Zhejiang provinces as well.