基于改进的标准化降水指数的黄河中游干旱情势研究

提出了一种基于旬累积尺度的月标准化降水指数(SPI)计算方法,该方法不仅考虑了前期降雨量对区域当前旱情的影响,因而对旱情的评估更为客观,同时在实际应用中更具有时间上的灵活性,更能体现气象干旱的累积效应和预报的时效性。计算了黄河中游山西省境内近40a(1971-2009年)各旬干旱指数,分析结果表明改进的标准化降水指数能够很好地表征黄河中游山西省境内的历史旱情状况。引入国际上常用的多种未来气候情景,研究分析了未来气候变化下2021-2050年黄河中游山西省境内地区旱情发展的可能情势,结果表明其存在对农业不利影响加重的可能,需要引起水资源管理部门的重视。

Drought trend estimation based on improved standard precipitation index for the middle reaches of Yellow River

An improved standard precipitation index(SPI) approach was proposed for better drought representation in this study,which not only allows for the antecedent precipitation thus more objective on drought evaluation,but is more flexible,more in-time and could incorporate more accumulated information.The SPI degrees of ten-day series were calculated for Shanxi province located in the middle Yellow River for 40 yrs from 1970 to 2009.The results show the improved SPI could represent the historical drought situation of this district in a better manner.Allowing for the future drought trends impacted by climate change,the current widely used climate scenarios all over the world were applied.The drought situations of Shanxi province during 2021 to 2050 were analyzed under future climate scenarios.The results indicate under future climate change the drought would show the possibility of more critical against water supply and agriculture production.In view of the uncertainty of future climate change,though not very high possibility for more serious drought,it still should be paid more attention by water resources management.