淮河上游地形对大暴雨的影响

The Influence of the Topography of the Huaihe's Upper Reaches on the Heavy Rainfall

本文分析淮河上游地形对大暴雨中心分布的影响事实，并以气流对云中水滴输送率公式进行定性解释．同时也指出地形影响暴雨雨量的机制是地形改变天气系统的流场，使气流对云团中水滴的输送率发生变化，导致云中水滴在动能较小的地区大量降落，形成暴雨中心．地形对暴雨雨量的增幅作用。

This article analyses the characteristics of the influence of Huaihe Upper reaches topography on the heavy rainfall,and makes a qualitative explanation toward the fact by using the formula of the transport rate of the airflow toward the water drops in the clouds.It also points out that the main reason of the increasing amount of the heavy rainfall is the reducing of the horiziontal wind vorticity caused by the topography.