海滦河流域的降水类型与旱涝灾害

PRECIPITATION TYPES AND THEIR RELA-TIONSHIPS WITH DROUGHT AND FLOOD IN HAIHE-LUANHE RIVER BASINS

本文通过对1956—1983年的季、年降水场的自然正交函数展开分析,揭示出流域的12种基本降水型,并根据逐年降水类型的变化,探讨了它与旱涝灾害的关系。得出:2型和1型是旱涝灾害的主要降水型;连续同型降水是形成重灾的一个主要原因,它具有多发性。

Twelve main precipitation types in Haihe—Luanhe River basins were revealed through the experience orthogonal function expansion analysis of seasonal and annual precipitation field during 1956—1983. And on the basis of the seasonal and annual changes of the precipitation types, the relationship between the precipitation types and drought and flood disaster are studied. The result shows that type 1 and type 2 are the principal precipitation types of drought and flood. The successive occurrence of the same type is the main cause of severe disasters. Its happening frequency is high.