基于Visual ModFlow的银川市地下水超采区水位预测

Prediction of water level in over-exploitation area of groundwater in Yinchuan City based on Visual ModFlow

应用地下水数值模拟技术对到地下水资源进行评价管理及预测,具有前瞻性和可靠性等优势。采用Visual Modflow软件构建银川市地下水超采区模型,并基于现状地下水位监测资料对模型进行率定验证,查明超采区地下水补排均衡要素及其占比情况。在此基础上,基于验证好的模型对银川市地下水超采区状况进行模拟评价,同时预测现状条件和替代水源条件下超采区未来5-10年水位与漏斗范围变化情况。结果表明:2020年研究区补给量大于排泄量,区域地下水水位逐步上升,与2020年区域监测井监测情况相符,进一步验证了模型的准确性,同时也说明银川市超采区治理效果较好,已基本实现采补平衡;在假设补给项稳定的情况下,按照银川都市圈西线供水工程建成通水后,逐步压减地下水水源地开采量来设置四种假定情景并分别进行地下水位预测,可从侧面印证银川市采用置换水源的方式开展超采区治理,效果良好,地下水可实现采补平衡。研究结果可为银川市及相同地质单元区域未来地下水水资源评价、管理、调度提供参考,也为新一轮超采区划定及治理提供了一种有效的分析方法。

The application of groundwater numerical simulation technology to evaluate,manage and predict groundwater resources has the advantages of foresight and reliability.The model of groundwater over-exploitation area in Yinchuan City was constructed by Visual Modflow software,and the model was calibrated and verified based on the current groundwater level monitoring data,and the balance elements and proportions of groundwater replenishment and discharge in the over-exploitation area were identified.On this basis,based on the verified model,the simulation evaluation of groundwater over-exploitation area in Yinchuan City is carried out,and the changes of water level and funnel range in the over-exploitation area in the next 5~10 years under the current conditions and alternative water source conditions are predicted at the same time.The results show that the recharge in the study area in 2020 is greater than the discharge amount,and the regional groundwater level will gradually rise,which is consistent with the monitoring of the regional monitoring wells in 2020,which further verifies the accuracy of the model.The balance of mining and replenishment has been basically achieved.Under the assumption that the recharge item is stable,according to the completion of the water supply project of the west line of the Yinchuan metropolitan area,after the water supply project of the Yinchuan metropolitan area is completed,the extraction of groundwater sources is gradually reduced to set up four hypothetical scenarios and predict the groundwater level respectively.It can be confirmed from the side that Yinchuan City adopts the method of replacing water sources to carry out over-exploitation area governance,and the effect is good,and the groundwater can achieve a balance of mining and replenishment.The research results can provide a reference for the future evaluation,management and dispatch of groundwater resources in Yinchuan City and the same geological unit area,and also provide an effective analysis method for a new round of over-exploitation area delimitation and governance.