渭河上游两次致洪暴雨过程的对比分析

对渭河支流上游两次致洪暴雨过程进行了对比分析,结果表明:在泾河上游,两次大暴雨的落区相差在100km以内;两次暴雨过程均给当地和渭河下游造成了严重的洪涝灾害;洪水过程的洪峰特点分别属于缓型洪水和陡型洪水;500hPa天气分型虽然一次为西南气流型,一次为西风槽型,但700hPa的直接影响系统基本相同.物理量诊断对比分析表明:在暴雨出现前12h,低层辐合、高层辐散的垂直结构已基本形成,到暴雨出现临近辐合辐散迅速加强,为暴雨形成和维持提供了非常有利的动力条件.

Contrast Analysis on Course of Two Flood Rainstorms along Upper Weihe River

A contrast analysis on the course of two flood rainstorms along upper Weihe river is made. The results show that in the upper Jinghe river, the two rainstorm regions are no more than 100 kilometers apart. The two rainstorms have resulted in heavy flood disasters to local area and Weihe valley~ one flood peak is slow flood and the other is steep flood. In the 500Hpa circulation pattern, one rainstorm is belongs to west-south airflow and the other belongs to west low-trough but the direct reacting system on 700Hpa is alike. The physics diagnosis contrast analysis show that, 12 hours before the rainstorm, congregation at low level and divergence at high level formed and are reinforced when rainstorm arrived. It provided the favorable dynamic condition to the formation and maintaining of the rainstorm.