潜水面与包气带水的动态耦合机制及其尺度效应

项目名称： 潜水面与包气带水的动态耦合机制及其尺度效应

项目编号： No.40802060

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 王旭升

作者单位： 中国地质大学（北京）

项目金额： 20万元

中文摘要： 潜水面与包气带水的耦合不仅是地下水循环的重要环节，也是决定流域水文-生态相互作用的内在机制之一。本项目把潜水面与包气带水的动态耦合关系作为地下水文学的重要考察对象，研究了考虑包气带水的潜水面运动非线性方程，分析了地下水承压-无压混合流的动力学行为，针对黑河流域中游地区分析了厚层包气带水分运动对地下水动态特征的影响，从区域尺度论证了地下水-蒸散发的动力学耦合机制。本项研究提出了可变给水度的潜水面运动方程，对经典Boussinesq方程起到了一种局部修正作用。本项目完善了前人提出的承压-无压横向水流模型，获得了近似解，更加准确的揭示了转换界面移动的一些非线性特征。抓住黑河干流中游存在巨厚的包气带这一特征，本项目通过模型分析指出了地下水二次补给的成因。对黑河流域盆地中下游地下水、地表水、包气带水的相互作用，应用耦合模型解释了区域尺度地下水与蒸散发的耦合行为。本项目还通过实验研究提出了获取砂土水分特征曲线的简易方法。

中文关键词： 地下水; 潜水面; 土壤水; 耦合; 黑河流域盆地

英文摘要： Coupling between phreatic surface and soil water in vadose zone is not only a key aspect in groundwater circulation, but also an inner mechanism in controlling the interactions between catchment hydrology and ecosystem. This project focus on the dynamic coupling between phreatic surface and soil water: investigating the nonlinear equation of phreatic surface in considering of soil water, analyzing the dynamic behavior of confined-unconfined mixed groundwater flow, investigating the role of thick vadose zone in groundwater regime in the middle reaches area in Heihe River Basin, observing the coupling between groundwater and evaportranspiration at regional scale. A new dynamic equation of phreatic surface with variable specific yield is developed, to partly improve the classical Boussinesq equation. Previous model of confined-unconfined groundwater flow is modified and approximated solution is obtained which more accurately reveals some nonlinear behaviors in the movement of the transfer interface. Stand on the existence of very thick vadose zone in the middle reaches area in Heihe River Basin, this study explained, through modeling analysis, the cause of second recharge event in groundwater regime. A coupling model is developed to investigate the coupling between groundwater and evaportranspiration at regional scale. It is linked to the interactions between groundwater, surface water and soil water in the middle and lower reaches of Heihe River Basin. In addition, a simple method is proposed to obtain the soil moisture retention curve of sand in laboratory.

英文关键词： Groundwater; phreatic surface; soil water;coupling; Heihe River Basin