基于Budyko假设的若尔盖流域径流变化归因分析

The attribution analysis of streamflow changes in the Zoige basin based on the Budyko hypothesis

变化环境下的水文循环研究是当今水科学研究的热点之一,研究流域水文过程变化的响应机制,对未来流域水资源规划及管理具有重要的现实意义。以若尔盖流域为研究区域,基于Budyko假设理论,应用敏感性分析方法,对若尔盖流域径流变化进行归因分析,结果表明:若尔盖流域径流对降水、潜在蒸散发和流域特征参数的敏感性系数分别为0.645 1、-0.234 7和-182.205 0,即若尔盖流域降水每增加1mm将导致流域径流增加0.645 1mm,潜在蒸散发每增加1mm将导致流域径流减少0.234 7mm,流域特征参数每增加1将导致流域径流减少182.205 0mm;若尔盖流域逐年径流呈明显的下降趋势,与基准期(1960-1990年)相比,变化期(1991-2011年)径流量减少了56.23mm(20.48%),其主要影响因素为流域下垫面特征的变化,其贡献率可达93.46%,而气候变化的影响仅占5.57%。

The hydrologic cycle research under changing environment is one of the hot topics in water science study.The study on the response mechanism to hydrological process changes is of great practical significance to future water resources planning and management.In this study,based on the Budyko hypothesis,we conducted attribution analysis of the streamflow changes in the Zoige basin by sensitivity analysis,and the results showed that:the sensitivity coefficients of streamflow to precipitation,potential evapotranspiration,and catchment characteristic parameter were 0.654 1,-0.234 7,and-182.205 0,respectively,which means that every 1 mm increase in precipitation would induce a 0.654 1 mm increase in streamflow;every 1 mm increase in potential evapotranspiration would induce a 0.234 7 mm decrease in streamflow;every increase of 1 in the catchment characteristic parameter would induce a 182.205 0 mm decrease in streamflow.The streamflow of the Zoige basin showed a significantly decreasing trend.Compared with the reference period(1960-1990),the streamflow of the change period(1991-2011)decreased by 56.23 mm(20.48%).The main influence factor was the change of underlying surface characteristics,whose contribution rate reached 93.46%.The climate change only contributed 5..57%.