广东省年最高水位多年一遇的极值计算

利用广东省各主要河流的20个水文站的年最高水位资料，采用皮尔逊—Ⅲ型分布理论和适线法进行重现期的极值计算分析。结果表明，采用这种方法拟合效果较好，大多数站点的绝对误差小于0．4m，相对误差小于5％；不管从现有资料分析，还是从多年一遇的极值分析，北江、东江、西江的极值距平值均较大，重现期T＝100a时半数站点的极值距平值在6．0m以上，其中西江流域的梧州站极值距平值最大达8．04m。因此，北江、西江、东江是广东省防洪的重点流域。

Computation of Extreme Water Levels for Main Rivers in Guangdong Province

With the information of annual maximum water levels from 20 stations, the water levels for those main rivers in Guangdong province are computed based on Pearson-III distribution theory and fitting line method. The results show that the fitting is effective with residuals less than 0. 4m, and the relative errors less 5%. It is found that water level departures from the averages in Beijiang, Dongjiang and Xijiang rivers are obviously larger than those in other rivers. In the case with extreme water level appearing every other 100 years, the records from half of stations show that water levels are higher than six meters. The highest deviation about 8.04 meters is recorded at Wuzhou station. To reduce the damage of flooding, Guangdong province should focus on the water levels of Beijiang, Dongjiang and Xijiang rivers.