干旱区与湿润区旱涝急转演变特征对比研究

Comparative study on change characteristics of drought-flood abrupt alternation in arid and humid zones

以长江、黄河和淮河流域为研究对象,基于标准化旱涝急转指数,利用趋势分析、变点检验、小波分析、随机森林等方法探究典型干旱区与湿润区旱涝急转演变特征及其驱动因子。结果表明:湿润和半湿润区是极端旱涝急转事件的高频发生区,干旱区是极端旱转涝事件的高频发生区;干旱区的突变发生在1998年,湿润区的突变在1978年,未来干旱区更易发生旱转涝事件,湿润区则相反;气象因子在湿润区对旱涝急转的贡献度更大,大气环流对干旱区的影响突出,旱涝急转与不同驱动因子间存在非线性关系。

Taking the Yangtze River,Yellow River,and Huai River basins as research objects,based on the standardized drought-wetness abrupt alternation index,this study explores the characteristics and driving factors of drought-flood abrupt alternation in typical arid and humid areas using methods such as trend analysis,change point test,wavelet analysis,and random forest.The results indicate that the humid/semi-humid areas are the high-frequency occurrence areas of extreme drought-flood abrupt alternation events,and the arid areas are the high-frequency occurrence areas of extreme drought to flood events.The mutation in arid areas occurred in 1998,while the mutation in humid areas occurred in 1978.In the future,arid areas are more prone to drought to flood events,while humid areas are the opposite.The contribution of meteorological factors to the rapid transition of drought and flood is greater in humid areas,and the impact of atmospheric circulation on arid areas is prominent.There is a non-linear relationship between the rapid transition of drought and flood and different driving factors.