基于MODFLOW的河套灌区井渠结合开采模式研究  

Optimizing Conjunctive Use of Groundwater and Cannel Water in Hetao Irrigation District Aided by MODFLOW

作　　者：杨威 毛威[1] 杨洋 朱焱[1] 杨金忠[1] YANG Wei;MAO Wei;YANG Yang;ZHU Yan;YANG Jinzhong(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan 430072,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《灌溉排水学报》2021年第12期93-101,共9页Journal of Irrigation and Drainage

基　　金：国家重点研发计划课题(2016YFC0501304);国家自然科学基金项目(51779178)。

摘　　要：【目的】探究河套灌区不同水文地质条件下适宜的井渠结合开采模式。【方法】利用实测地下水位等资料,基于MODFLOW建立了灌区三维地下水动态模型并率定、验证,在灌区4个典型灌域分别选取典型井渠结合区,设置了4种井灌区面积和11种渠井结合比,共44种井渠结合开采模式,预测了各模式下地下水埋深变化,以井灌区地下水平均埋深不超过3 m为标准,优选了各灌域适宜的井渠结合开采模式。【结果】(1)建立的河套灌区三维地下水数值模型充分反映了灌区内实际水位变化特征,可用于井渠结合后地下水埋深预测。(2)相同井灌区面积和渠井结合比条件下,解放闸、乌兰布和灌域井渠结合井灌区地下水平均埋深最小,永济灌域次之,义长灌域最大,乌兰布和灌域典型井渠结合区的地下水等埋深线最密集,义长灌域次之,永济和解放闸灌域最稀疏。(3)井灌区面积一定时,井灌区地下水平均埋深随渠井结合比的增大而减小,但减幅随渠井结合比增大有变缓趋势。【结论】由于水文地质条件差异,各灌域适宜井灌区面积和渠井结合比均有所不同,乌兰布和、解放闸、永济、义长灌域井渠结合井灌区面积分别不宜超过12.25、12.25、9、6.25 km^(2),渠井结合比分别不宜小于2.5、2.5、3.0、3.3。【Objective】Hetao Irrigation District relies on Yellow River water for irrigation,but excessive use of the river water had resulted in soil salinity.Jointly using groundwater and river water has been postulated as a feasible mitigation technology,and the purpose of this paper is to present the results of a study on how to achieve optimal use of groundwater and surface water.【Method】A three-dimensional groundwater model for the region was calibrated and verified using MODFLOW based on measured groundwater depths and other datasets.We then applied the model to four typical well-canal combination areas in four sub-districts:Wulanbuhe,Jiefangzha,Yongji and Yichang.44 scenarios with four different well-irrigation areas and 11 kinds of canal-well combination ratios were considered.For each scenario,we predicted how the groundwater depth changed with the well-canal combination ratio and well-irrigation area.【Result】(1)The three-dimensional groundwater model correctly captured physical properties of the aquifers and soils and reproduced the observed change in groundwater depth at different scenarios.(2)When the ratio of well-irrigated to canal-irrigated areas was the same,the average groundwater depth in Jiefangzha and Wulanbuhe was the shallowest followed by Yongji,with that in Yichang the deepest.Isograms of groundwater depth in areas with well-canal irrigation in Wulanbuhe was the densest,followed by Yichang,with Yongji and Jiefangzha the sparsest.(3)When the well-irrigated area was constant,the average groundwater depth decreased asymptotically as the canal-well combination ratio increased.【Conclusion】The suitable canal-well combination ratio and well-irrigation area for controlling groundwater depth not exceeding 3 m varied with the sub-districts due to their difference in hydrogeological conditions.The well-irrigation areas in Wulanbuhe,Jiefangzha,Yongji and Yichang should not exceed 12.25 km^(2),12.25 km^(2),9 km^(2)and 6.25 km^(2)respectively,with their associated ratio of canal-irrigated area to w

关 键 词：河套灌区 井渠结合 渠井结合比 MODFLOW 

分 类 号：S273.4[农业科学—农业水土工程]