基于SPI指数和CI指数的东北地区降水集中度与旱涝关系研究

The Effects of Precipitation Concentration on Drought/Flood Events in Northeast China Based on CI and SPI

研究以东北地区43个气象站1976-2015年逐日降水量数据为基础,采用降水集中度指数CI描述降水集中程度,标准化降水量指数(SPI)描述旱涝状况,以分析全年以及不同季节的降水集中度与旱涝关系为目标开展研究。结果表明:①东北地区年降水集中度高于各个季节的降水集中度,四季中冬季降水集中度最低;②在丘陵山地地区年CI指数与年尺度SPI正相关关系显著,降水多的年份降水分布也更为集中,更容易造成洪涝灾害;③不同季节之间,春、秋季有超过半数的站点的降水集中度与SPI正相关关系显著,春季在降水少的年份由于降水分布均匀,无效降水多,加剧了干旱。研究结果对于深入理解东北地区不同季节降水分布特征及对旱涝事件影响具有重要意义。

Daily precipitation data during 1976-2015 at 43 meteorological stations located in northeast China are used to calculate yearly and seasonal precipitation CI(Concentration Index) and SPI(Standardization Precipitation Index). This study aims at analyzing the relationship between precipitation concentration character and drought-flood events in different seasons. Results show that yearly precipitation CI is higher than seasonal CI. CI for winter is the lowest among the four seasons. There are significant positive correlations between yearly CI and SPI at the stations located in hilly areas. This means in those areas precipitation distributed more concentration in wet years. Seasonal CI and SPI are significantly correlated for over half stations in spring and autumn. But the relationship is not obvious in summer and winter. Those results are meaning for better understanding the precipitation distribution characters during different seasons and its impact on droughts and floods in northeast China.