北方岩土二元介质坡地壤中流运动特性及模拟

The water resource effect of soil conservation measures is a hotspot and difficulty in the current research; scholars have not reached any consensus on this subject in the academia. One of the main reasons resulting in different opinions is that the physical mechanism of impact from soil conservation measures on the water cycle has not been systematically explored and found. Subsurface flow exists in slope characterized by rock-soil dual entity pervasively, and plays an important role in the sloped water circulation system. The project makes researches on conversion mechanisms and hydrological processes of subsurface flow in slope characterized by rock-soil dual entity under different vegetation conditions (five kinds of basic configurations including coniferous forest, broadleaf forest, conifer forest, grassland and bare land) by taking slope characterized by rock-soil dual entity as the study sites, the slope as the basic scale, and movement direction of infiltrated soil water as the entry point, and makes mathematical simulation by overland flow - subsurface flow coupled model, in order to obtain the breakthrough in critical steps of slope water cycle theory, thus laying a foundation for systemic research on the impact from soil conservation measures on infiltration, evapotranspiration, subsurface flow, surface flow, and groundwater. This project is conducive to exploration of physical mechanism of impact of soil conservation measures on the water cycle, and has an important significance to enrich and improve forest hydrology content. It is greatly practical to conduct water resource regulation by rational soil conservation measures, and to maximize the benefits in water resources allocation works and soil conservation works.

水土保持措施的水资源效应是当前研究中的热点和难点，对该方面的理论研究学术界至今尚存诸多观点。水土保持措施对水循环影响的物理机制尚未被系统地揭示是产生观点分歧的主要原因之一。壤中流在岩土二元介质坡地普遍存在，且在坡地水循环系统中具有重要作用，为此本项目选择太行山区岩土二元介质坡地为研究地点，以坡地为基本尺度，以入渗土壤水转化方向为切入点，研究岩土二元介质坡地不同下垫面和降雨条件下壤中流的水文过程、产流特征，并利用坡面流-壤中流耦合模型进行数学模拟，力求在坡地水循环理论的关键环节取得部分突破，为系统研究水土保持措施对入渗、蒸散、壤中流、地表径流、地下水的影响提供理论支持。本项目研究将有助于系统地揭示水土保持措施对水循环影响的物理机制，对丰富、完善森林水文学基础理论具有重要意义，同时对通过合理配置水土保持措施实现水资源调控，进而实现水资源配置工程、水土保持工程的效益最大化具有重大现实意义。

本项目选择太行山区岩土二元介质坡地为研究地点，以坡地为基本尺度，以入渗土壤水转化方向为切入点，结合野外观测和室内试验，开展了不同水土保持植被类型影响下的土壤空间异质性研究，分析了当地土壤降雨入渗过程及再分布特征，研究了壤中流水文过程及产流机制，构建了坡面流-壤中流耦合方程，对包括壤中流、地表径流在内的坡地产流机制进行从定性到半定量的初步探讨，并将坡地产流模型等相关成果在我国北方泾河流域进行了应用和验证。本项目研究将有助于系统地揭示水土保持措施对水循环影响的物理机制，对进而实现水资源配置工程、水土保持工程的效益最大化具有重大现实意义。总体上，本项目通过2014~2016年三年的基础调研、野外观测、室内实验等工作，达到预期目标。