基于标准化降水指数的淮河流域干旱 演变特征分析

利用淮河流域35个气象站点的降水资料，采用标准化降水指数(Standardized Drecipitafion in- dex , SP1)分析了淮河流域近50年(1961 } 2010年)的年度干旱指数，并利用干旱发生频率、干旱站次比和干旱强度三项干旱指标分析了淮河流域的干旱演变特征。研究结果表明，近50年来，淮河流域以轻旱、中旱为主，重旱、特旱相对较少，有干旱发生面积有逐年递减而发生强度呈增强趋势。在当前气候变化背景下，淮河流域干旱对农业生产的不利影响有减小的趋势。

SPI based analysis on evolvement feature of drought in Huaihe River Basin

Based on the precipitation data from 35 meteorological stations in Huaihe River Basin,the annual drought index of nearly 50 years(1961～2010)is analyzed herein with the standardized precipitation index(SPI),and then the evolvement feature of drought in the basin are also analyzed with three drought indexes,i.e.drought frequency,ratio of stations with drought and drought intensity.The study result shows that Huaihe River Basin is mainly dominated by light drought and medium drought within a period of nearly 50 years,while severe drought and extreme drought are relatively rare therein along with a trend of that drought covered area decreases,however,the drought intensity increases year by year.Under the current status of the climate change,there is a tendency of the decrease of the unfavourable impact from drought on the agricultural production in Huaihe River Basin.