关键词: 旱涝急转, 时空特征, 指数修正, 降水分析, 趋势性分析, 贵州省

Abstract: According to the daily precipitation data of 19 rainfall gauging stations from1968 to 2017 and the feature of Guizhou Province, DWAAI (dry-wet abrupt alternation index) was revised. The spatial and temporal evolution characteristics of dry-wet abrupt alternation (DWAA) events in Guizhou Province in the past 50 years were analyzed. The results showed that: (1) The calculation results matched well with typical DWAA events in the history, which suggested that the revised DWAAI has good applicability in Guizhou Province. (2) Temporally, the occurrence time of DWAA events were mainly distributed from April to October. Interannualy, the station proportion of dry-wet abrupt alternation and intensity posed increasing trend. The intensity of DWAA in autumn showed a decreasing trend, while in other seasons, both the territorial scope and the intensity of DWAA showed an increasing trend, among which the intensity had obviously increasing trend in spring and summer and the territorial scope had increased significantly in summer. (3) The occurrence frequency of DWAA was generally decreasing from east to west in Guizhou Province. In terms of seasonal spatial variation characteristics, the occurrence frequency of DWAA in the south was higher than in the north in spring. It was easier to occur in the north-central of Guizhou Province and had most extensive area in summer, in autumn the occurrence frequency presented decreased trend from east to west. The scope of vulnerable areas were expanding constantly with time. The research results are of great significance to disaster prediction and early warning and drought and waterlogging prevention in the region.

Key words: droughts-floods abrupt alternation, spatial and temporal characteristics, modified index, rainfall analysis, trend analysis, Guizhou Province