基于Budyko假设的金溪流域径流变化归因分析

Attribution of Runoff Variation in Jinxi Basin Based on Budyko Hypothesis

[目的]探究金溪流域径流变化特征及其原因,对于水库运行调度及水资源管理具有重要指导作用。[方法]基于1982-2015年流域气象水文数据以及植被NDVI数据,采用线性回归法、Mann-Kendall突变检验及滑动T突变检验法分析径流变化特征,进一步采用Budyko水热耦合平衡方程计算各影响因子对流域径流变化的贡献率。[结果]金溪流域年径流深、降雨量均呈不显著上升趋势,变化速率分别为3.89 mm/a,8.43 mm/a。潜在蒸散发量呈显著上升趋势,变化速率为1.17 mm/a。通过突变检验可将金溪流域径流序列分为基准期1982-2002年和变化期2003-2015年。金溪流域径流变化归因分析表明:下垫面变化对径流变化的贡献率为123.55%,潜在蒸散发的贡献率为33.83%,降雨贡献率为-57.38%,流域下垫面变化主要源于植被情况显著改善,其中NDVI在基准期上升速率为0.005/10 a,在变化期上升速率为0.024/10 a。[结论]导致金溪流域径流变化的主要源于植被情况的显著改善,金溪流域径流变化的归因分析为金溪流域的水资源利用提供了理论支持。

[Objective]To explore the characteristics and causes of runoff change in Jinxi Basin plays an important guiding role in reservoir operation and water resources management.[Methods]Based on the meteorological and hydrological data and Normalized Difference Vegetation Index(NDVI)data from 1982 to 2015,linear regression method,Mann-Kendall mutation test and sliding T mutation test were used to analyze the characteristics of runoff change.The contribution rate of each influencing factor to runoff change was calculated by using Budyko coupled equilibrium equation.[Results]The results show that the annual runoff depth and rainfall in Jinxi Basin had no significant upward trend,with the changing rates of 3.89 mm/a and 8.43 mm/a,respectively;the potential evapotranspiration showed a significant upward trend at a rate of 1.17 mm/a;through mutation test,the runoff series of Jinxi Basin could be divided into the base period from 1982 to 2002 and the change period from 2003 to 2015;attribution analysis of runoff change in Jinxi Basin showed that the contribution rate of underlying surface change to runoff change was 123.55%,the contribution rate of potential evapotranspiration was 33.83%,and the contribution rate of rainfall was-57.38%.[Conclusion]The change of underlying surface of the basin is mainly due to the significant improvement of vegetation situation in which the increase rate of NDVI is 0.005/10 a in the base period and 0.024/10 a in the change period.