基于标准化降水指数的近51a山东临沂市旱涝时空特征

基于1961—2011年临沂市10个气象观测站的逐月降水数据，采用标准化降水指数（SPI），分析了临沂市旱涝时空分布特征。结果表明：临沂市旱涝变化具有阶段性特征，1960年代初中期和1970年代初中期，雨涝频繁；1960年代中后期和1970年代中后期及整个1980年代，干旱频繁；1990年代到21世纪初早期旱涝交替发生，2003年以后以雨涝为主。冬春季干旱呈弱的减轻趋势，秋旱呈弱加剧趋势，夏季旱涝变化趋势不明显。北部山区、西部丘陵、南部平原的旱涝变化总体上具有相对一致的趋势，但在1960年代中期、1980年代中期、21世纪初早期西部丘陵的旱涝变化幅度较其他2个区域要大。全市旱涝变率在21世纪初早期最大，1970年代中后期最小，3个区域的变率总体上表现出与全市大致相同的趋势，2004年以后南部平原旱涝变率持续增大。

Spatial and Temporal Characteristics of Drought/Flood in Linyi Based on Standard Precipitation Index （SPI） in Recent 51 Years

Based on the monthly precipitation data in Linyi during 1961 -2011 and the standard precipitation index, the spatial- tem- poral characteristics of drought/flood in Linyi were analyzed. The results indicated that the flood was more severe in the early 1960s and 1970s, and drought was more frequent in the late 1960s, the 1970s and in the whole 1980s, drought and flood manifested alter- nately from the 1990s to the early 21st century. Oecurence of drought in spring and winter tended to decrease weakly, while in autumn tended to be more severe, there was no obvious change in summer. There was a relative consistence in variation of flood/drought in the northern mountains＇ region, western hills＇ region and southern plains, but the change range of drought/flood in western hills was lager than that in other two regions in the middle 1960s, the middle 1980s and the early 21st century. The most drastic drought/flood varia- bility occurred in the early 21st century, and in the late 1970s, the variability was minimum. The variability in three regions was con- sistent with that the whole city in the mass, but in southern plains the variability of flood/drought increased since 2004.