基于SPI的辽宁省庄河市近35年干旱演变特性研究

Study on drought evolution characteristics of Zhuanghe City in Liaoning Province in recent 35 years based on SPI

庄河市是辽南地区的重要水源地,分析其干旱演变特性有利于该地区水资源的合理开发与利用,对于防旱减灾、合理布局产业结构具有重要的现实意义。本文根据庄河市1984年1月1日至2018年12月31日的逐日降水数据计算了1个月、3个月、6个月、12个月共4个不同时间尺度下的标准化降水指数(SPI),并基于SPI对该地区近35年的年际与季节干旱演变特征进行了分析。结果表明:在年际变化方面,庄河市的SPI在2000年以前波动幅度较小,说明该地区的降水在时间上分布较为均匀;但自2000年以来,SPI序列出现较大的波峰与波谷,说明降雨的分布不均匀性有所增强;SPI的时间序列趋势线斜率为负值,说明该地区整体上呈现偏旱趋势,因此其水资源压力不断增大。在季节演变特征方面,夏季干旱和秋季干旱呈现增强趋势;秋旱的发生频率最高,而夏旱的出现频率最低。本研究结果可为庄河地区的抗旱减灾与水资源规划提供科学依据。

Zhuanghe city is an important water source in southern Liaoning Province.Analyzing its drought evolution characteristics is conducive to the rational development and utilization of water resources in this area,and has important practical significance for drought prevention and disaster reduction and rational layout of industrial structure.According to the daily precipitation data from January 1,1984 to December 31,2018 in zhuanghe city,the standardized precipitation index(SPI)of 1 month,3 months,6 months and 12 months was calculated,and the characteristics of interannual and seasonal drought evolution in this area in recent 35 years were analyzed based on SPI.The results show that,in terms of interannual variation,the fluctuation range of SPI in zhuanghe city before 2000 is small,which indicates that the precipitation in this area is evenly distributed in time;However,since 2000,there have been large peaks and valleys in SPI sequence,which shows that the uneven distribution of rainfall has been enhanced;The slope of SPI's time series trend line is negative,which indicates that the region as a whole presents a drought trend,so its water resources pressure is increasing.In terms of seasonal evolution characteristics,summer drought and autumn drought show an increasing trend;autumn drought has the highest frequency,while summer drought has the lowest frequency.The research results can provide scientific basis for drought relief and water resources planning in Zhuanghe area.