东江流域三种时间尺度降雨量时空特征分析

Analysis on Spatial-Temporal Characteristics of Rainfall in Three Time Scales in Dongiiang River Basin

研究东江流域月最大半小时降雨量、月最大日降雨量、月降雨量的时空特征,发现月最大半小时降雨量和月最大日降雨量在时空分布上都与月降雨量分布基本一致,认为两者的时空分布特征主要受气候因素影响,同时在一定程度上受热带气旋及地形因素的影响;各种影响因素对两者的作用强度有所不同。在年际变化上,东江流域汛期月平均最大半小时降雨量在1951—1988年总体变化趋势为不显著递增,并在1972年出现显著突变,置信度达95%;而汛期月平均最大日降雨量在1953—2010年总体变化趋势为不显著递减,没有明显突变现象,与汛期平均月降雨量的整体演变趋势相似。

This paper studied the spatial-temporal feature of monthly maximum half-hour rainfall, monthly maximum daily rainfall and monthly rain- fall in Dongjiang River basin, found that the spatial-temporal distribution of monthly maximum half-hour rainfall and monthly maximum daily rainfall are both basically in accordance with monthly rainfall＇ s, considered that they are influenced mainly by climate, and influenced by tropical cyclone and landform to a certain extent. The degree of influence of the same factor to different heavy rainfall is different. In the period from 1951 to 1988, the average of monthly maximum half-hour rainfall during flood season showed an indistinctive increasing trend, and had a significant abrupt change in the 1972 with the confidence of 95%. However, in the period from 1953 to 2010, the average of monthly maximum daily rainfall during flood season showed an indistinctive decreasing trend, and had no abrupt change. But there＇ s a similar change trend between monthly maximum daily rainfall and monthly rainfall.