珠江流域旱涝时空演变规律分析

Spatial-temporal Characteristics of the Drought and Flood in Pearl River Basin

根据1959-2009年珠江流域44个测站逐月降水量资料,用Z指数确定单站旱涝等级。结果表明:干旱高发区春季以兴义、望谟和灵山、玉林地区,夏季以靖西和佛冈为主要发生区域,秋季在南雄区域频率较高,冬季集中在龙州、南宁和南雄。洪涝高发区位于流域东部的盘县、兴义和西部的广宁、南雄;夏季集中在望谟附近;秋季分布较不均匀,高频率区域分布在深圳、南雄、梧州和沽益等地;冬季以连县为高频发生区。通过对降水资料的EOF分析发现,流域春、夏、秋、冬4季的旱涝变化主要呈现为整体一致性的旱或涝分布,此外也存在着东旱西涝、东涝西旱2种分布类型。说明珠江流域旱涝分布除了受大尺度的天气系统控制外,还受到局地地形等因子共同影响。

With river basin from 1959 to 2009 in 44 measuring station＇s monthly precipitation data throughout the year, drought and flood level Z index is used to determine the single station. The results show that Xingyi, Wangmo and Lingshan, Yulin are main frequent-drought areas in spring in the Pearl River Basin. Jingxi and Fogang are the main areas in summer. There is a higher frequency in the south of the male in the region in fall. The high incidence areas for flooding are Panxian and Xingyi in the east of the Pearl River Basin and Guangning, Nanxiong in the south of it. In summer it is concentrated on sight hume and the area nearby. Inequalities for autumn distribution in high frequency value areas are mainly distributed in Shenzhen, Nanxiong, Wuzhou, and selling profit, and Lianxian often suffers from disaster in winter. Based on the precipitation data of EOF analysis it is found that the change of drought and flood in spring, summer, autumn and winter in the Pearl River Basin mainly appears as the overall consistency distribution, expression is consistent with the drought or water logging. In addition, there are two kinds of distribution types that also the east west water logging, drought water logging east west dry type. The Pearl River Basin is not only affected by large-scale weather system control and outside, but also by the local terrain, ground level and the interplay of other facors.