秦皇岛洋河-戴河沿海平原海水入侵数值模拟分析

The Numerical Study for Seawater Intrusion in Yanghe and Daihe Coastal Plain of Qinhuangdao City

在分析洋河-戴河沿海平原水文地质条件的基础上,运用FEFLOW软件,建立了三维变密度溶质运移模型。以2002-12至2004-12的地下水位和水质观测资料,对模型进行了率定。用检验后的模型对研究区海水入侵原因进行了模拟分析,对不同开采条件、不同防治措施下的海水入侵发展趋势进行了预测。模拟结果表明:滨海地区超采地下水是造成海水入侵的根本原因,河流长期低水位导致海水倒灌加剧了海水入侵的程度;在滨海地区,只要地下水降落漏斗存在,就会引发海水入侵进一步向内陆移动;同时,根据预测结果,提出了防止和减缓海水入侵的措施。

Based on the analysis of the hydrogeological conditions of the Yanghe - Daihe costal plain, a three-dimensional variable density flow and transport model was constructed using FE- FLOW software. The model was calibrated and tested by using water-level and water-quality data of groundwater from December 2002 to December 2004. The cause of seawater intrusion in the ar- ea was analyzed, and the tendency of seawater intrusion was forecasted under different conditions. It is concluded that the main reason for seawater intrusion is excessive groundwater exploitation, and seawater flowed inversely into the rivers has aggravated the situation because of the lower river water level. In coastal areas, as long as the exhaustion cone of groundwater exists, the seawater will intrude into inland. At the same time, proper measures are suggested to prevent seawater in- trusion according to the results of the simulation.