渭河流域径流变化趋势及其影响因素分析

Analysis on Runoff Trend and Influence Factors in Weihe River Basin

针对渭河流域华县水文站径流出现断流的现象,探讨渭河流域径流量的变化和影响因素显得尤为重要。以渭河流域华县站1956—2000年径流资料为基础,运用R/S分析法,对渭河流域径流序列进行了趋势分析。同时,对渭河流域径流变化的影响因素也进行了分析。结果表明,华县水文站年径流序列的赫斯特系数为0.7784,表明渭河流域径流具有持续下降的趋势。以1956—1969为基准期进行比对,1970—2000年渭河径流量年均减少3.79×109m3,其中气候作用减少1.96×109m3,占减少量的51.7%,人类活动作用减少1.83×109m3,占减少量的48.3%。

Aimed at the stream flow cut-off of Weihe river basin at Huaxian station, it is important that the runoff trend and influence factors are analyzed in this area. According to the data of runoff in Weihe river basin from 1956 to 2000, the changing trend of runoff at Huaxian station is analyzed by using the R/S analysis （Rescale Range Analysis）. At the same time, the influence factors of runoff are analyzed. Results show that the Hurst coefficient is 0. 778 4, showing that the runoff trend is on the persistent decline. The annual average runoff had been reduced by 3.79 × 10^9 m^3 from 1970 to 2000, compared to the runoff from 1956 to 1969. Among the influence factors, the reduction influenced by climate is 1.96 × 10^9 m^3 and the reduction influenced by human activities is 1.83 × 10^9 m^3 , amounting for 51.7% and 48.3% of the total reduction, respectively.