基于标准化降水指数的济宁旱涝演变特征分析

为济宁旱涝灾害的监测、评估提供支持，进而为减轻该区域旱涝灾害损失、合理利用水资源提供科学依据，笔者利用济宁市11县区1959—2013年逐月降水资料，采用标准化降水指数SPI方法，分析了济宁近55年的旱涝变化特征。结果表明：（1）济宁市的旱涝变化呈现明显的阶段性特征，1959—1975、2003—2013年均属偏涝阶段，1976—2002年属偏旱阶段。（2）济宁市各季节的旱涝呈频繁交替的特点，春季和冬季的雨水呈弱增多趋势，夏、秋季雨水呈弱的减少趋势，但变化趋势均不明显。（3）济宁旱涝发生极为频繁，洪涝事件每5~6年发生一次，干旱事件每4~5年发生一次。21世纪初期旱涝变率最大，其次是20世纪60年代，70年代至90年代变化较为平稳，70年代末期至80年代初期出现明显干湿变化，90年代变率小，表现最平稳。（4）从区域中可看出济宁南部区域旱涝变率不大，基本为旱涝相互交替的特征，北部和中部区域总体表现和全市大致相同的趋势，呈现“偏涝—偏旱—偏涝”的变化特征。

Analysis of Drought-Flood Evolvement Characteristics in Jining Based on Standardized Precipitation Index

In order to offer support for monitoring and assessment of droughts and floods in Jining, and offer scientific basis for reducing the loss caused by regional drought and flood disaster and rational utilization of water resources, based on the standardized precipitation index SPI, the evolvement characteristics of droughtflood were analyzed by using the month by month precipitation data of 11 counties of Jining from 1959 to 2013. The results showed that: (1) the characteristics of drought-flood showed an obvious stage characteristic, 1959 to 1975 and 2003 to 2013 were waterlogging stage, while 1976 to 2002 was partial drought stage; (2) the characteristics in each season showed a frequent alternation characteristic, the rain water showed a weak increase trend in winter and spring, while a weak decrease trend in summer and autumn, but the variation trend was not obvious; (3) the drought-flood occurred frequently in Jining, the flood event occurred once every 5-6 years, the drought event occurred once every 4-5 years; the variability of drought-flood was the maximum in early 21st century, followed by 1960s, the variability of 1970s to 1990s was relatively stable, the variability of late 1970s to the early 1980s was obvious, and 1990s was the steadiest stage with the minimum variability; (4) the variability of drought- flood was small in the southern area of Jining, which showed a characteristic of drought-flood alternation, the variability in north and central area was similar to that of all the city, showed a “partial waterlogging-partial drought-partial waterlogging”change characteristic.