钦州市降雨及入海河流径流演变规律与趋势分析

Analysis of Rainfall and River Runoff Change Tendency in Qinzhou City

依据钦州市58a平均降雨量和3条入海河流控制站径流量长序列资料,采用滑动平均、线性回归、Spearman、M-K及R/S法综合分析降雨径流的趋势性及突变特征。结果表明,钦州市降雨量总体呈弱增加趋势,增加率为0.742mm/10a,而茅岭江、钦江、大风江流域径流量存在总体减少趋势,减少率分别为0.2×108m^3/10a、1.1×108m^3/10a、0.4×108m^3/10a。运用复Molet小波分析多时间尺度周期性,降雨量序列存在5个时间尺度,22a和15a时间尺度分别为序列第一、三主周期;径流量序列存在3个时间尺度,其中22a和8a时间尺度分别为径流量序列第一、二主周期。

Based on the data of the average rainfall from 1956 to 2013 and the runoff series of the 3 rivers in Qinzhou City over the past 50 years, the sliding average method, linear regression, M-K method and R/S method were used to analyze the tendency and mutation characteristics of the rainfall and runoff. The results show that there is a slow increase trend of the rainfall in Qinzhou City with the increase rate of 0.742mm/10 a, and there is a decrease trend of the runoff in the river basins of Maolingjiang, Qinjiang and Dafengjiang with the decrease rates of 0.2 ×10^8m^3/10 a, 1.1 ×10^8m^3/10 a and 0.4 ×10^8m^3/10 a respectively.Molet wavelet analysis was made to get 5 time scales in the rainfall series, of which 22-year and 15-year scales are respectively the first main period and second main period of the rainfall series. There are 3 time scales in the runoff series, of which the 22-year and 8-year scales are respectively the first main period and second main period of the runoff series.