基于组合经验频率法的珠江三大水系干旱年景遭遇分析

Analysis of drought years in three major river systems of the Pearl River based on combined empirical frequency method

选用珠江流域西江高要站、北江石角站和东江博罗站1956—2016年天然河川径流量资料,分析了各江河径流变化特性和开发利用情况;根据距平百分率评价了丰枯变化情况;并基于组合经验概率分析了三大水系枯水遭遇概率和连续枯水概率。结果表明:①西江径流量丰富,年际变化小;东江径流量较少,年际变化大。②西江、北江和东江的径流量年内变化都很大,枯季易发生干旱。③西江与东江枯水年遭遇的概率远低于北江与东江枯水年遭遇的概率。④三大水系同时出现枯水年的概率为14.7%,同时出现特枯年的概率为6.6%。⑤61 a中2 a以上连续枯水,西江、北江和东江各发生3次、6次和4次。研究结果对做好广东省水资源优化配置,在时间上蓄峰补谷、在空间上以丰济枯,支撑社会经济高质量发展具有一定指导作用。

Using natural river runoff data from Xijiang Gaoyao,Beijiang Shijiao,and Dongjiang Boluo Stations in the Pearl River Basin from 1956 to 2016,the characteristics of runoff changes and development and utilization of each river were analyzed;Based on the percentage of percentage deviation,the changes in wet and dry seasons were evaluated;And based on the combination of empirical probabilities analysis,the probability of encountering low water and the probability of continuous low water for three major water systems were analyzed.The results show that:①Xijiang River has abundant runoff with a small interannual variation;The runoff of Dongjiang River is relatively small,with significant interannual variations.②The runoff of the Xijiang,Beijiang and Dongjiang rivers varies greatly throughout the year,and drought is prone to occur during the dry season.③The probability of encountering Xijiang and Dongjiang in dry years is much lower than that of encountering Beijiang and Dongjiang in dry years.④The probability of three major water systems experiencing a dry year at the same time is 14.7%,and the probability of experiencing a extremely dry year at the same time is 6.6%.⑤In the past 61 years,there have been consecutive dry seasons for more than two years,with 3,6 and 4 occurrences in the Xijiang,Beijiang,and Dongjiang rivers respectively.These results have a guiding role in optimizing the allocation of water resources in Guangdong Province,storing peaks and supplementing lacks in time,and using abundant resources to replenish dry in space for supporting high-quality socio-economic development.