控制海水入侵的地下水多目标模拟优化管理模型

A multi-objective simulation-optimization model constrained by the potential seawater intrusion

为实现滨海含水层地下水开采-回灌方案优化、控制海水入侵面积和降低海水入侵损失等多重管理目标,建立了海水入侵条件下地下水多目标模拟优化管理模型SWT-NPTSGA。模拟模型采用基于变密度流的数值模拟程序SEAWAT来模拟海水入侵过程。优化模型采用小生境Pareto禁忌遗传混合算法NPTSGA来求解,该算法在保证多目标权衡解的收敛性和计算效率的前提下,能维护整个进化群体的全局多样性。将SWT-NPTSGA程序应用于一个理想滨海含水层地下水开采方案和人工回灌控制海水入侵的优化设计中,结果表明该管理模型能够同时处理最大化总抽水流量、最小化人工回灌总量和最小化海水入侵范围等3个目标函数之间的权衡关系。通过采用人工回灌海水入侵区的减灾策略,既能增加滨海地区的供水量,又可减少海水入侵的范围,由此进一步验证了模型的有效性和可靠性。

A linked simulation-optimization model （SWT-NPTSGA） using the niched Pareto tabu search combined with a genetic algorithm （NPTSGA） , is developed for deriving multiple objective management strategies for coastal aquifers, involving seawater intrusion control, mitigation measures, and groundwater resources optimization. The superiority of the NPTSGA-based optimization approach lies in its ability to find the appropriate balance between diversity and convergence of solutions with high computational efficiency. Density-dependent groundwater flow and solute trans- port simulator SEAWAT is used to generate input-output patterns of groundwater extraction rates and salinity levels. The performance of the presented simulation-optlmization model is evaluated through a synthetic example application. The main advantage of the developed model is that it can make a tradeoff among maximization of total pumping rate, minimization of total artificial recharge and minimization of the extent of seawater intrusion. The seawater intrusion mit- igation measures by artificial recharge can increase groundwater supply and reduce the area of seawater intrusion. The optimization results show potential feasibility of the proposed methodology in solving multiple objective optimization models for managing coastal aquifers.