基于RDI指数的云南1960～2013年旱涝变化特征分析

Drought and Flood Change Characteristics Based on RDI Index from 1960 to 2013 in Yunnan Province

利用云南省40个气象站逐日降水量和蒸发量数据,采用RDI指数研究云南旱涝灾害的时空分布特征。结果表明:云南年际、季节旱涝与历史记录十分一致,1960~2013年云南年RDI指数呈下降趋势,表现为变干趋势,但不显著;2001年以前发生雨涝年的强度和站次比较干旱年明显,在此之后,发生干旱年的强度和站次比较雨涝年明显。季节尺度上,春季呈显著的变湿趋势,夏、秋、冬季呈不显著的变干趋势;春、夏季分别突变于1980年和1965年。从空间分布上来看,年、夏、秋、冬季整体以滇南和滇东北呈变干趋势,而滇西北呈变湿趋势;春季除滇东北外,其余区域均呈变湿趋势;年际、季节干旱频率以滇西北、滇西南、滇东南较高;年、春、夏、秋季重旱频率以滇中和滇东十分突出;年、夏、秋季特旱频率均以滇东北十分突出,春季滇中和滇东北极易发生特旱;冬季以滇中重旱频率较高,特旱极易发生在滇西北、滇西南、滇东北。年际、季节雨涝频率以滇西、滇东南较突出。年重、特涝频率以滇西南十分突出;春季重涝频率以滇西南和滇中较突出,特涝频率以滇中和滇东南较突出;夏季重、特涝频率均以滇西北较高;秋季重涝频率以滇西北较高,特涝频率以滇东南较高;冬季重涝频率以滇东南较突出,特涝频率以滇西北较高。

Based on the daily precipitation and evaporation data of 40 meteorological stations in Yunnan Province, the spatial and temporal distribution characteristics of flood and drought were studied by using the RDI index. The results showed that： The annual and seasonal scale droughts and floods is consistent with the historical record in Yunnan Province, The annual RDI index showed a downward trend and a tendency to drought, but not significant; The intensity and stations proportion of floods significantly than droughts before 2001 years ; since 2002 the intensity and stations proportion of drought than flood significantly. On the seasonal scale, the spring has a significant wetting trend, the summer, autumn and winter has not significant drying trend; droughts and floods of the spring mutated in 1980, droughts and floods of the summer mutated in 1965. From the spatial distribution, annual, summer, autumn and winter was drought trend in the South and Northeast of Yunnan Province ; there has a wet trend in Northwest of Yunnan Province; the rest of the region showed a wet trend, except for a drought trend in northeast of Yunnan Province. Annual and seasonal drought frequency was more higher in Northwest, Southwest and Southeast of Yunnan Province ; the heavy drought frequency was very prominent in annual, spring, summer and autumn in Center and East of Yunnan Province; the extreme drought frequency in the annual, summer and autumn was very prominent in Northeast of Yunnan Province; there was very prone to drought in Center and Northeast of Yunnan Province in spring; the frequency of heavy drought was more higher in Central of Yunnan Province and the extreme drought was very likely to occur in Northwest, Southwest and Northeast of Yunnan Province in winter. The annual and seasonal flood frequency was more prominent in West and Southeast Yunnan Province; the heavy and extreme flood frequency was very prominent in southwest of Yunnan Province in annual ; the frequency of heavy flood was more prominent in Southwest and central of Yunnan Province and extreme flood occurred in Central and Southeast of Yunnau Province in spring ; the frequency of heavy and extreme flood was more higher in northwest of Yunnan Province in summer; the frequency of heavy flood was more higher in Northwest and extreme flood more higher in Southeast of Yunnan Province in autumn; the frequency of heavy flood was more prominent in Southeast and extreme flood in Northwest of Yunnan Province in winter.