基于数值模拟法的傍河水源地井群设计和优化

为保证傍河水源地水资源的可持续开发利用，并尽量减少由此对生态环境造成的负面影响，对水源地的开采井群进行优化设计是必要的。本研究以开采量（20×104 m3?d?1）和地下水位允许降深（14 m）为目标函数，以袭夺江水比例、地下水位降落漏斗范围、理论单井供水能力为约束条件，以开采井数量、井间距离、井河距离3个设计参数为变量，应用Visual MODFLOW 2010.0软件对地下水流场的演化规律进行了模拟预测，并基于预测结果对设计方案进行了比选，得到了最优参数组合。结果表明:9口开采井、井间距离为100 m、井河距离为50 m为最优方案；在该方案条件下，傍河水源地的供水能力为2.1×105 m3?d?1，其中袭夺的江水量占66%；形成的地下水位降落漏斗面积为2.8×106 m2，中心区降深为11.5 m，对环境产生的扰动最小，环境负效应也最小。 

Pumping well groups on riverbanks: design and optimization by numerical simulation

To ensure sustainable development and utilization of water resources, and to minimize negative impacts on ecological environment, it is necessary to optimize design of pumping well group of riverside water source. With water yield (20×104 m3?d?1) and allowable drawdown of groundwater level (14 m) as objective functions, with proportion of river water captured by wells, area of cone of depression of groundwater level, and theoretical water supply capacity of a single well as constraint conditions, with design parameters (well number, distance between two adjacent wells and distance between well and river) as variables, evolution of groundwater flow field under three exploitation schemes was simulated and predicted with Visual MODFLOW 2010.0. An optimal scheme was obtained by comparison of predicted results. The optimal scheme was found to be: a combination of nine wells, with distance between two adjacent wells at 100 m, and distance between well and river at 50 m. Under optimal conditions, supply capacity of the source was 2.1×105 m3?d?1, 66% of which was from the river; area of depression cone at the groundwater level of the source was 2.8×106 m2, corresponding drawdown at groundwater level of the central cone was 11.5 m. This has the least disturbance to environment and the least negative effect on t environment under condition of optimal scheme.