淮河流域农业干旱分区对比分析

A Comparative Analysis of Agricultural Drought Zoning in Huaihe River Basin

淮河流域处于我国南北气候过渡带,降水量空间分布差异明显,干旱频发。利用淮河流域各省、市、自治区20个气象台站1951年-2008年逐日降水量数据,运用WAP(Weighted Average of Precipitation)指数、空间克里格及回归分析等方法,对淮河流域农业干旱分区进行时空对比分析。研究表明:在时间上,1951年-2008年淮河流域WAP指数整体上呈现明显波动,平原轻旱区的WAP指数波动最大,出现干旱的变异性最大,但干旱程度较低,平原中旱区的WAP指数波动最小,出现干旱的变异性较小。在空间上,淮河流域WAP指数总体呈现从西北向东南、从内陆向沿海递增趋势,并有两个高值中心:以淮安为代表的平原轻旱区处于东南高值中心,其WAP值为2.49,区域内干旱程度最低;以信阳和六安为代表站点的山丘重旱区中的豫西山丘区位于西南部高值中心,其WAP值为2.58。但由于WAP指数主要适用于反映平原地区的干旱程度,对山区干旱程度的反映效果不佳,因此,在平原地区,WAP值呈现低丘陵平原重旱区-低丘陵平原轻旱区-平原中旱区-平原轻旱区的递增趋势,干旱程度呈递减趋势。淮河流域农业干旱分区的时空差异对比分析,可为各农业干旱分区提供不同的抗旱防灾参考。

Huaihe River Basin is located in a climatic transition zone of North-South border line of China,with different rainfall distribution and frequent drought.Using the daily precipitation data between 1951 and 2008 from 20 meteorological stations,we conducted,with weighted average of precipitation（WAP） index,spatial Kriging and regression analysis methods,a comparative study of agricultural drought zoning in Huaihe River basin.The results showed as follows.Temporally,the WAP index fluctuated significantly as a whole,with the highest index and variance in light-drought plain and lowest index and variance in middle-drought plain.Spatially,WAP index decreased from the southeast to the northwest and from inland to coast,and there were two highest value points：the southeastern point was in the light-drought plain of Jiangsu Province such as Huaian with 2.49 of WAP index,meaning the minimum drought degree of the region;the southwestern point was in the heavy-drought hilly area of western Henan Province such as Xinyang and Liuan with 2.58 of WAP index.However,the WAP index was mainly applied to plain area,while the result of drought degree was poorly demonstrated in mountain area.Therefore,in the plain area,WAP index increased in an order of low-hilly plain with heavy-drought,low-hilly plain with light-drought,plain with middle-drought and plain with light-drought,while the drought degree was in a decreasing order.This analysis provides a reference for other areas to drought prevention.