基于地下水均衡模型的河套灌区地下水补给排泄量分析  

Modelling groundwater recharge and discharge in Hetao irrigation district using water balance model

作　　者：高雅文 查元源 董斌[1] GAO Yawen;ZHA Yuanyuan;DONG Bin(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,武汉430072

出　　处：《灌溉排水学报》2024年第4期74-81,共8页Journal of Irrigation and Drainage

基　　金：国家重点研发计划项目(2021YFC3201204);国家自然科学基金(52279042)。

摘　　要：【目的】多灌少排的灌溉制度导致河套灌区地下水位上升,土壤盐碱化问题突出,模拟分析地下水补给排泄过程能够增进对河套灌区地下水变化过程的理解。【方法】建立考虑排水过程的生育期-冻融期地下水均衡模型,分别采用LH-OAT算法和ES-MDA算法进行参数敏感性分析和参数率定,并应用在河套灌区义长灌域。【结果】地下水均衡模型中地下水埋深对潜水蒸发极限埋深、潜水蒸发系数、灌溉水补给系数敏感。模型在河套灌区应用精度良好,能够充分反映灌域地下水埋深和地下水排水量的变化过程。对灌域地下水补给排泄关系进行分析发现,灌域地下水补给主要来源于灌溉水入渗,灌域地下水排泄主要去向为潜水蒸发。在5、7、10月,灌域地下水储量由于较大的灌溉用水和秋浇引水量而增加;9月份潜水蒸发量对地下水消耗量较小,这导致地下水储量增加;6、8月由于引水的补给量减少,部分地下水储量被潜水蒸发消耗。【结论】本文建立的考虑冻融期和地下水排水过程的水量均衡模型应用在义长灌域效果较好,灌域不同月份地下水储量变化受引水量、地下水埋深、排水量等多种因素主导。【Background and Objective】Irrigation in the Hetao irrigation district relies on water diversion from the Yellow River.However,its flat terrain coupled with suboptimal irrigation and drainage practices over the past decades has resulted in groundwater table rise,leading to significant soil salinization.This paper develops a water balance model to calculate groundwater recharge and drainage in the irrigation district.【Method】A comprehensive water balance model was established by accounting for seasonal freezing and thawing,as well as groundwater drainage.It was then applied to the Yichang area in the irrigation district.Sensitivity of the model was analyzed using the Latin Hypercube-One-At-a-Time(LH-OAT)method;parameters in the model were estimated using the ensemble square-root method of data assimilation(ES-MDA).【Result】Sensitivity analysis reveals that change in groundwater depth is sensitive to parameters including the critical depth of phreatic groundwater table below which groundwater evaporation ceases,coefficient of phreatic groundwater evaporation and coefficient of irrigation water recharge.The model accurately reproduces the variation in groundwater depth and groundwater drainage in the studied area.Groundwater recharge primarily emanates from irrigation water infiltration,while drainage is predominantly through groundwater evaporation.The analysis identifies seasonal fluctuations in groundwater storage,which is influenced by factors such as irrigation water diversion,groundwater depth and groundwater drainage rate.【Conclusion】The proposed water balance model accounts for freezing and thawing,as well as groundwater discharge.Practical application shows the model is robust for modelling groundwater dynamics in the Yichang area in the Hetao irrigation district.Monthly change in groundwater storage is influenced intractably by irrigation practices,groundwater dynamics and climatic condition.

关 键 词：地下水 水均衡模型 补给 排泄 河套灌区 

分 类 号：P333.1[天文地球—水文科学]