珠江流域降雨结构时空演变特征研究.pdfVIP

Journal of Water Resources Research 水资源研究, 2012, 1, 93-101 doi:10.4236/jwrr.2012.13014 Published Online June 2012 (/journal/jwrr.html) Spatial-Temporal Changes of Precipitation Structure * across the Pearl River Basin, China Juntai Peng1,2, Qiang Zhang1#, Xiaohong Chen2 1Department of Water Resources and Environment, Sun Yat-sen University, Guangzhou 2Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education Institute, Sun Yat-sen University, Guangzhou Email: pengjt@, #zhangq68@ Received: May 3rd st th , 2012; revised: May 21 , 2012; accepted: May 27 , 2012 Abstract: Daily precipitation data over the Pearl River basin (1960-2005) from 42 rain gauges is used in this article. Precipitation indices such as annual total precipitation amount, annual total rainy days, annual pre- cipitation intensity and annual mean rainy days are defined. These precipitation indices are analyzed using the modified Mann-Kendall method. Results show that: 1) Decreasing trend of precipitation is found mainly in the middle and upper Pearl River basin. Rainy-days are decreasing almost over the entire basin. Thus, the precipitation intensity of Pearl River basin is increasing, particularly in the middle and the eastern parts of the basin; 2) The occurrence and fractional contribution of wet periods with shorter durations (2 - 5 d) are tend- ing to be predominant while longer durations are decreasing in recent decades; 3) Heavy storms are easy to occur in the eastern of the basin during shorter durations. Higher risk of floods