挠力河流域地表水-地下水联合模拟及未来水资源量评估

Joint modelling of surface-groundwater interaction and assessment of future water resources in the Naoli River Basin

为了定量评估变化环境下挠力河流域水资源量变化,建立基于VIC和Visual MODFLOW的流域地表水-地下水联合模拟模型,根据实测地表径流和观测井地下水位数据进行参数率定与验证。结果表明,率定期和验证期地表水模拟的决定系数和纳什系数均大于0.7,模拟的观测井地下水位和实测地下水位趋势相同,相关系数达到0.9以上,说明模型设置合理。基于此,评估未来CanESM5气候模式(CMIP6)三种排放情景下(SSP1-2.6、SSP2-4.5、SSP5-8.5)挠力河流域2021-2050年的地表径流量和地下水水位变化。结果表明,三种未来情景下的年径流量呈不同程度的减少趋势;维持现状开采条件,未来地下水位呈现降低趋势,水资源开发利用将面临更大挑战。本研究成果可为流域湿地与农业用水配置,区域水资源规划与管理提供科学支撑。

In order to quantitatively evaluate the water resources of Naoli River under changing environment,this study establishes a coupled surface-groundwater model based on VIC and Visual MODFLOW models.The model parameters are calibrated and verified using the measuredsurface runoff data and groundwater level data of the observation well.Results show that the determination coefficient and Nash coefficient of the runoff simulation are both above 0.7,and the overall trend of the simulated and observed groundwater levels are of high consistency with a correlation coefficient of 0.9,suggesting that the model is applicable.On this basis,we predict the changes in surface runoff and groundwater level during 2021 to 2050,under three emission scenarios(SSP1-2.6,SSP2-4.5 and SSP5-8.5)of the CanESM5 climate scenario(CMIP6).Results show that the annual runoff under three future scenarios will decrease at different rates.If the current mining conditions are maintained,the groundwater level will decrease in the future,and the exploration and utilization of water resources will face a greater challenge.This study can provide scientific support for water resources allocation between irrigation and wetland,and for the regional water resources planning and management.