干旱指数在辽河流域的应用分析

Application of drought index in Liaohe Basin

由于农业用水增加、工业污染严重,造成辽河流域干旱程度加重,利用2010—2015年辽河流域昌图县、康平县、法库县逐月降水量资料及年降雨量数据,通过降水距平百分率、标准化降水指数(SPI)、降水Z指数合理评价了辽河流域干旱情况,并比较3种干旱指数的评价效果。分析了三个地方的干旱情况,研究并比较了降水距平百分率、SPI、降水Z指数的评价效果。结果表明:降水距平百分率反映干旱程度较轻;与降水Z指数相比,SPI指数能较客观地反映辽河流域干旱程度。为辽河流域定量研究干旱事件提供合理的指标依据,为不同研究区根据自身特点选择适合的干旱指标奠定理论基础。

Due to the increasing agricultural water and heavy industrial pollution,the drought degree in Liaohe Basin is aggravating.According to the monthly precipitation data and annum rainfall data of Changtu County, Kangping County,and Faku County nearby Liaohe Basin,reasonable evaluation of the drought condition is made via studying the precipitation from flat percentage,the standardized precipitation index （SPI）, as well as the Z index of precipitation.The drought conditions in the above three places were analyzed, and the effect of precipitation anomaly percentage,SPI and precipitation Z index were also studied and compared.The results show that the percentage of precipitation reflects the degree of drought to a lesser degree.Moreover, compared with Z index,SPI index can objectively reflect the degree of drought in Liaohe basin.This study provides a rea- sonable basis for the quantitative study of dwught events in Liaohe basin,and lays a theoretical foundation for selecting suitable drought indicators according to their own characteristics.