CAJ | 학술논문

建立了三维变密度对流弥散水质数学模型来研究山东省烟台夹河中、下游地区咸淡水界面的运移规律。以四面体为基本离散单元，推导出三维海水入侵变密度水质模型求解的数值方法，其中水流方程求解时运用了迦辽金有限单元法。溶质运移方程求解时运用了欧拉拉格朗日混合方法，将对流项与弥散项分离，用传统迦辽金有限元方法求解弥散项；采用自适应MOC-MMOC法求解对流项，以消除人工过量和数值弥散。根据地下水的潮汐效应观测信息，确定了含水系统的海底延伸边界；利用该地区地下水水头及水质长观资料识别了模型的水文地质参数，探讨了夹河地区海水入侵的原因：认为夹河下游地区滨海地带地下水过量开采是造成烟台地区海水入侵的主要原因。此外，海水随潮定期地倒灌进入夹河，通过局部岩性天窗侵入淡水含水层加剧了沿夹河河床两侧地下水的咸化。同时还预测了几种情况下地下水的水质演化趋势，为防止和减轻夹河地区海水入侵提供合理、科学的依据。
건립료삼유변밀도대류미산수질수학모형래연구산동성연태협하중、하유지구함담수계면적운이규률。이사면체위기본리산단원，추도출삼유해수입침변밀도수질모형구해적수치방법，기중수류방정구해시운용료가료금유한단원법。용질운이방정구해시운용료구랍랍격랑일혼합방법，장대류항여미산항분리，용전통가료금유한원방법구해미산항；채용자괄응MOC-MMOC법구해대류항，이소제인공과량화수치미산。근거지하수적조석효응관측신식，학정료함수계통적해저연신변계；이용해지구지하수수두급수질장관자료식별료모형적수문지질삼수，탐토료협하지구해수입침적원인：인위협하하유지구빈해지대지하수과량개채시조성연태지구해수입침적주요원인。차외，해수수조정기지도관진입협하，통과국부암성천창침입담수함수층가극료연협하하상량측지하수적함화。동시환예측료궤충정황하지하수적수질연화추세，위방지화감경협하지구해수입침제공합리、과학적의거。
A three-dimensional variable density flow and transport model hasbeen developed to study the salt water intrusion in the Jahe River Basin, Shandong Province, China. Based on tetrahedral element, the authors derived the numerical approximation procedure of 3D density-dependent saltwater intrusion model. The density-dependent flow equation is solved numerically by Galerkin FEM formation. The solute transport equation is solved by means of a coupled Eulerian-Lagrangian method in which advection part is separated to dispersion part and calculated by a hybrid method of characteristics so as to improve the precision of concentration solution of advective part. In using of density-dependent tidal effect model, the equivalent boundary toward sea in confined aquifer is determined according to tidal fluctuation information. The aquifer parameters in the Jahe River Basin are estimated by converging long-term observation data of hydraulic head and chloride concentration. Through numerical analysis and prediction, it is concluded that the main reason for saltwater intrusion is excessive groundwater exploitation and improper arrangement of pump wells in the lower reaches of the Jahe River Basin. Besides, seawater comes into river because of tidal effect. Therefore, groundwater near river is contaminated by saltwater in tongue form. By predicting the tendency of water saline quality under several conditions, two measures are suggested to prevent salt water intrusion.