南水北调水源在密怀顺水源地回灌的地下水水质变化试验

Experiment of groundwater quality change for simulating the South-to-North water into the Mihuaishun aquifer

南水北调水源进京后,部分水源计划将进入密怀顺水源地回补严重亏损的地下水。水源地地下水水质的未来变化引起了人们的关注。本次研究通过开展动态含水层模拟试验,分析了南水北调水源进入含水层过程中地下水水质变化,并利用溶质运移模型,在不考虑吸附、降解等水岩相互作用等条件下,模拟了试验土柱中各常规组分的水质变化。研究表明:南水北调水源进入含水层过程中,对地下水水质的稀释作用占主导地位,其它水岩相互作用对地下水水质的影响程度较小,南水北调水源在密怀顺水源地回补地下水是可行的。为此,南水北调水源回补地下水后,不仅能够涵养并增加水源地的地下水资源,而且能够改善地下水水质,保证水源地的供水安全。

After the South-to-North water entering Beijing,part of the water will be injected into the aquifer of Mihuaishun groundwater wellfield. Close attention is paid to the groundwater quality change. To examine the groundwater quality change,a soil column experiment was executed to simulate the South-to-North water entering the aquifer. The results show that the dilution effect of the South-to-North water plays a leading role and other water-rock interactions have little effect on groundwater quality. A solute transport model was established to verify this point of view and it is found that it is correct. Using the South-to-North water to supply the Mihuaishun groundwater wellfield is feasible. Consequently,using the South-to-North water to recharge the groundwater not only conserves and increases groundwater resources,but also improves the groundwater quality and ensures the safety of water supply.