锦江水库对下游径流年际变化影响分析

An Analysis of the Effect of Jinjiang Reservoir on the Downstream Runoff Interannual Variation

基于仁化、长坝2个研究站点及参照站点犁市1958-2009年的日径流资料,分别采用滑动平均法和Mann-Kendall检验法定性与定量分析各站点径流年际变化趋势,再联合R/S分析法计算出Hurst指数评估趋势的持续性,最后用改进的Mann-Kendall法作突变点检验,以此来分析锦江水库对下游径流年际变化的影响。同时,分析研究区域的降水年际变化以印证水库对下游径流年际变化的影响。结果表明,建库后多年平均降水量增加,锦江下游多年平均径流量却减少;Mann-Kendall检验表明建库后锦江下游仁化段在汛期(4、5、6月)的月径流量年际间呈显著下降趋势,年径流总量虽成下降趋势,但Hurst指数显示这种趋势的持续性很弱;突变检验表明锦江下游年径流在2004-2008年期间发生突变。总体而言,锦江水库对锦江下游的影响程度要大于对干流浈江的影响。

Based on the daily flow at Renhua ,Changba and Lishi stations covering 1958-2009 ,the moving average method and Mann-Kendall test are used in this paper to analyze the effect of Jinjiang reservoir on dow nstream runoff inter-annual variation ,the R/S analysis method is used to evaluate the persistence of runoff tendency ,and the modified Mann -Kendall is used to test a sudden change of runoff .Besides ,annual precipitation tendency of Jinjiang Basin also require analyzing .The results show that the average runoff between 1994 and 2009 is smaller than before ,although precipitation is more than before at Jinjiang Basin .Mann-Kendall test shows that downstream runoff appears to have a strong downward trend in April ,May and June at Jinjiang ;the downward trend of annual runoff is not obvious and the Hurst index shows that the trend has a very weak persistence .A sudden change test shows what happened between 2004 and 2008 .In general ,the effect of Jinjiang Reservoir on Jinjiang is greater than that on Zhenjiang .