基于改进水文模拟法的洛河径流变化归因分析

Attribution Analysis of Runoff Changes in Luo River Basin Based on Improved Hydrological Simulation Method

随着社会经济快速发展,高强度人类活动对径流过程的影响愈发强烈。为了探究洛河流域人类活动对径流变化的影响,在分析洛河流域径流演变特征的基础上,基于SWAT模型,通过考虑水库模块以及下垫面动态变化对水文模拟的影响,对传统水文模拟法进行了改进。应用改进后的水文模拟法,定量分析了水库建设、下垫面动态变化等人类活动微观因素对径流变化的影响。结果表明:①1961-2020年洛河流域径流量呈显著减少趋势,平均每年减少约0.12亿m^(3),突变检验表明洛河流域径流量在1989年发生显著突变,由此将研究序列划分为基准期(1961-1988年)和人类活动影响期(1989-2020年);②通过分区域参数率定方式构建的SWAT模型可以较好地模拟洛河流域径流过程,在率定期和验证期纳什效率系数NSE均大于0.8,相对误差RE均小于10%;③气候变化和人类活动对径流减少的贡献率分别为32.9%和67.1%,人类活动是导致径流变化的主要因素;人类活动微观因素中故县水库建设对径流影响最大,贡献率为47.9%;下垫面动态变化对径流减少的贡献率为-3.0%;其他人类活动如小型水库、橡胶坝、於地坝和渠系引水工程建设对径流减少的贡献率为22.2%。研究成果可为洛河流域水资源合理开发利用提供科学依据。

With the rapid development of the social economy,the impact of high-intensity human activities on the runoff process is becoming increasingly pronounced.In order to explore the influence of human activities on runoff changes in the Luo River Basin,this study,based on the analysis of the characteristics of runoff evolution in the basin,improved traditional hydrological simulation methods using the SWAT model.By incorporating the reservoir module and considering the impact of dynamic changes in land use on hydrological simulation,the improved hydrological simulation method was applied to quantitatively analyze the impacts of micro-scale human activities,such as reservoir construction and land use changes,on runoff changes.The results show:①From 1961 to 2020,the annual runoff in the Luo River Basin exhibited a significant decreasing trend,with an average annual reduction of about 0.12 billion m^(3).The Pettitt mutation test revealed a significant change in runoff in 1989,leading to the division of the study period into a baseline period(1961-1988)and a human activity impact period(1989-2020).②The SWAT model,parameterized using a regionalized approach,effectively simulated the runoff processes in the Luo River Basin.With the inclusion of the reservoir module,the model's performance was further improved,achieving Nash-Sutcliffe efficiency coefficients(NSE)greater than 0.8 and relative errors(RE)less than 10% during both calibration and validation periods.③The contributions of climate change and human activities to runoff reduction were 32.9% and 67.1%,respectively,with human activities being the primary factor driving runoff changes.Among the micro-scale human factors,the construction of Gu County reservoir had the largest impact on runoff,contributing 47.9%.The contribution rate of underlying surface dynamic change to runoff reduction is -3.0%.Other human activities,such as small reservoirs,rubber dams,earth dams,and canal systems,contributed 22.2% to runoff reduction.The findings of this study provide a scientific basis for the rational development and utilization of water resources in the Luo River Basin.