浅埋地下水反馈作用下的太湖流域平原区侧向产流机理研究

The plain area frequently suffered flood disasters due to the Low-lying land and human activities. During the rainfall event in Taihu plain areas, shallow groundwater response quickly, the water content in soil, groundwater and surface water transfer between each other frequently. Especially, low-lying land and pond play a major role in the rainfall-runoff generation and concentration, which provide the outlet for the shallow groundwater. Typical dry land is chosen for the hydrological experimental research in this study by using modern observation techniques of hydrological experiments and hydrological modeling method. The study works on the impact of side-way runoff to the soil infiltration rate, the runoff time and flow path. Through summarizing the relation between the shallow ground water and low-lying land, building the surface land- saturated-unsaturated moisture conversion in two-way. According to the hydrological model affected by the shallow ground water and low-lying land, the study is to establish the coupling model of surface and ground water applied in the dry land of plain area in Taihu basin. This study will provide the scientific basis of hydrologic forecast and water resources assessment in the plain area, also for the flood control and disaster reduction.

地势低洼及人类活动影响使得平原区时常遭受洪涝灾害影响，太湖流域平原区降雨条件下，浅层地下水位响应迅速，土壤水、地下水和地表水之间的水分转化十分密切，沟渠及湖塘等洼地为浅层地下水提供了出流途径，对产流过程具有控制作用。本研究选取平原区具有代表性产流特性的下垫面-旱地开展水文实验研究，采用现代观测技术、水文实验及水文模拟方法，分析平原区旱地降雨产流特征，研究侧向产流过程对地表填洼水量、土壤下渗率、地表产流时间和汇流路径的影响，总结浅层地下水与洼地等的补排水关系，建立地表－饱和－非饱和带水分双向转换关系方程，提出地下水埋深与微地形影响下的产流模式，构建太湖流域平原区典型区域地表与地下水耦合模型。为平原区水文预报和水资源评价提供科学基础，为流域防洪减灾提供科学支撑。

地势低洼及人类活动影响使得平原区时常遭受洪涝灾害影响，太湖流域平原区降雨条件下，浅层地下水位响应迅速，土壤水、地下水和地表水之间的水分转化十分密切，沟渠及湖塘等洼地为浅层地下水提供了出流途径，对产流过程具有控制作用。本研究选取平原区具有代表性产流特性的下垫面-旱地开展水文实验研究，采用现代观测技术、水文实验及水文模拟方法，分析了平原区旱地降雨产流特征，降雨前地下水初始埋深与土壤蓄水量呈良好的线性正相关关系，反映了该地区浅层地下水与土壤水的强相互作用，可将地下水初始埋深作为前期土壤水分估算的指标。结果表明地表以下0~0.4 m深度的土层是土壤水分变化最频繁剧烈的地带；研究了侧向产流过程对地表填洼水量、土壤下渗率、地表产流时间和汇流路径的影响，洼地蓄水量范围为4.72～8.03 mm，总结了浅层地下水与洼地等的补排水关系；提出地下水埋深与微地形影响下的产流模式，野外实测数据参数反演得到的土壤水分特征曲线参数与实验室测定的各参数取值差异较大，各深度范围野外实测的曲线相比实验室测定的曲线更符合粉质粘壤土的特征以及田间真实情况。该研究为平原区水文预报和水资源评价提供科学基础，为流域防洪减灾提供科学支撑。