中文摘要：

利用珠江流域42个气象站点1951—2011年的月降水与气温数据，计算了3个月尺度的标准化降水蒸散发指数，采用旋转经验正交函数时空分解方法，将珠江流域划分成了5个干旱变化特征均质性区域。并根据游程理论选取历时和强度2个特征变量，基于多变量区域频率分析的方法对珠江流域的干旱风险进行了评估。广义正态分布和皮尔逊三型分布分别优选为不同分区的干旱历时边缘分布，广义帕雷托分布优选为干旱强度边缘分布，区域copula函数则分别为Clayton和Archl3copula。从区域的角度，贺江、桂江、左江和右江流域地区遭遇的干旱风险较大，应视为珠江流域的重点干旱风险区。而从行政管理的角度，广西为干旱风险管理的重点省份。

英文摘要：

The 3-month standardized precipitation and evapotranspiration index was calculated based on the monthly precipitation and temperature data of 42 meterological stations in the Pearl River basin from 1951 to 2011. The Pearl River basin was divided into 5 subregions characterized by the variation of drought based on the rotated empirical orthogonal function method. The duration and intensity of drought were selected to be the characteristic variables according to the run theoq~, and the drought risk assess- ment was made across the Pearl River basin by using a multivariate regional frequency analysis approach. The five subregions divided from the Pearl River basin are all homogeneous, and the goodness-of-fit tests indicate that generalized normal and Pearson type m distributions are best for the duration as a regional marginal distribution for different subregions, while generalized Parato distribution is best for the intensi- ty. The Clayton copula is the best-fit regional copula for subregions one, three, and five, and the Archl3 copula is best for subregions two and four. Considering the drought return years as a risk, different dis- tricts across the Pearl River basin might suffer different drought risks. From the perspective of region, the districts of Hejiang, Guijiang, Zuojiang and Youjiang River basin will suffer a higher drought risk than others and should be caught enough attention. While from the perspective of administration, Guangxi willbe the most dangerous province for all kinds of drought risks.