海河流域地下水开采初期数值模拟及水量平衡分析

海河流域平原区地下水长期过度开采已引起了严重的环境问题,水资源的不断枯竭也制约着当地经济的可持续发展,成为国家一直关注的问题。作为地下水管理的方法之一,建立了地下水数值模型。对海河流域平原区地下水开采初期状态作了模拟分析,模拟结果显示:该区域地下水年补给量为156.6亿m3,其中,山前侧渗17.5亿m3,降雨入渗补给136亿m3,河道入渗3.1亿m3;地下水的排泄途径为河道基流88.5亿m3,蒸散发50.1亿m3,排泄入海15.2亿m3,黄河内滩侧渗排出1.8亿m3,总排泄量为156亿m3,地下水收支基本平衡。地下水的总体流向为自北、西、南指向渤海湾,吻合于地形坡度变化。模拟结果为水资源管理和水环境修复提供数据依据。模型也为下一步地下水大量开采状态的模拟提供初始水头条件、地质物理参数和边界条件。

Simulation of Groundwater Exploitation at Early Stage and Analysis on Water Budget in Haihe River Basin

Overexploitation of groundwater in Haihe River basin has caused significant environmental problems.The decline of groundwater resource also affects the sustainable development of the local economics.The shortage of water resources in Haihe River basin has become a major attention of the government.As one of the management tools,a groundwater model was constructed for the Haihe River basin.The model was used to simulate the groundwater exploitation at early stage in the area.The model indicated that the annual inflow to groundwater is 156.6×108m3,of which 17.5×108m3 for lateral flux from mountains,136×108m3 for rainfall recharge,3.1×108m3 for river recharge.Groundwater discharges via rivers(88.5×108m3),evapotranspiration(50.1×108m3),sea(15.2×108m3) and inner flooded area of Yellow river(1.8×108m3).Groundwater was at a natural balance.Groundwater flows from the north,west and south boundaries to the Bohai Sea,which is consistent with the sloping direction of the land surface.The modeling results provided data for water resource management and remediation of water environment.The model also provided initial head condition,physical parameter values and boundary conditions for the simulation of the mass exploited condition as the next step.