傍河地下水源地数值模拟与评价研究——以沈阳市浑河李官堡水源地为例

傍河水源地以其水量稳定、水质洁净等优点在我国北方普遍应用,地下水资源的准确评价为其良性运行的关键。结合实例,运用VisualM odflow对傍河水源地进行模拟,并在此基础上对其地下水资源进行评价及优化开采模拟分析。通过研究发现:①傍河水源地的模拟对河流的敏感性最强,其次为人工开采,而表征地下水系统特征的K、μ、a等参数的影响却不明显;②傍河水源地的模拟关键在于河流的处理。对非完整河流,在河床底部设置一层弱透水的缓冲区可取得满意效果;③傍河水源地的地下水资源量丰、枯年份相差不大,比较稳定;同时,地下水的资源量是个变量,随开采量增大而增大,且与开采井到河流的距离有关;④运用建立的水源地模型,可方便直观地对地下水开采进行优化调整,以更充分地袭夺地表水资源,从而促进水源地的良性生产。

Research on Numerical Simulation and Evaluation of Riverside Source Field - A Case Study of Liguanpu Riverside Source Field in Shenyang City

Riverside source fields are widely employed in northern China owing to its stable supplying ability and pure water quality.So great attention has been paid and efforts have been devoted to the study of the rules of this kind source field by many experts and scholars.According to their studies,the rational evaluation of groundwater is the premise which guarantees the efficient source field running.But it is a complicated proceeding as to how to evaluate the groundwater rationally.Based on the hydrogelogical conditions of Liguanpu riverside source field in Shenyang city,this paper discusses the correlated problems of numerical simulation and groundwater resource evaluation in riverside source field.To further the study,the problem of optimizing groundwater withdrawal in riverside source field is also conducted.Visual MODFLOW was used in this study to support the research.Visual MODFLOW is the most popular groundwater system simulation software at present,it's fully-integrated package combining powerful analytical tools with a logical menu structure and easy-to-use graphical tools allows us to create,run,calibrate amd visualize the results of a groundwater model easily. Through the research,several conclusions are drawn as follows:(1)River is the most sensitive factor in riverside source field simulation,and the second sensitive factor is the artificial withdrawal,while hydrogelogical parameters such as K,μ and a are not as dominative as expected to the simulation model.(2)The key point in riverside source field simulation lies in the dealing of a river.To an incomplete river,it is useful to set a weak permeable layer under the riverbed in simulation.(3)The evaluation results indicate that the amount of groundwater resources is relatively stable between dry and rainy year.But the amount of groundwater does increase with the increase of pumping.It is also influenced by the distance between the pumping wells and the river,the smaller the distance is,the bigger the amount of groundwater will become.The prime reason of these characteristics is that the groundwater resource of riverside source field is mainly recharged by the corresponding river.(4)With the help of constructed groundwater flow model,it is convenient to visualize the modeling result and then adjust the pumping spots and the amount of groundwater withdrawal,so that the surface water can be fully induced to the groundwater,and thus optimizing the source field's production and eventually making it sustainable developed.The above findings are used mainly to deal with groundwater amount but have nothing to do with groundwater quality.Actually,in order to insure a riverside source field developing smoothly,such factors as water pollution,water environment and so on should be studied synthetically.