太行山区坡地暂时饱和区形成机理及渗流补给特性

为了研究岩土特性对坡地雨水转化及再分配的影响，采用时域反射仪(TDR)对太行山区坡地岩土水分进行了长期连续监测，分析了岩土水分特性的时空变异。结果表明：太行山区坡地岩土水分变化存在时空变异性，坡地0～100 cm岩土层内岩土水分含量在垂直空间上与季节上均呈“低-高-低”的变化趋势，同时土壤层与岩体层的结合部位在8月份前后存在暂时饱和区；坡地岩土介质的空间变异性，特别是岩土二元结构的地质结构特性为暂时饱和区的形成提供了地质条件，而强降雨过程为暂时饱和区的形成提供了水文条件，暂时饱和区的水分状态达到或超过饱和状态的时间与前期岩土水分含量及降雨特性有关；该暂时饱和区的存在为坡地渗流中“侧向优先流”及“垂向优先流”的产生创造了有利条件，两个方向上的“优先流”相互作用，促进了岩土水分的快速下渗，提高了地下水的转化效率。

Formation mechanism of instantaneous saturated zone and seepage characteristics in the slope of Taihang Mountain areas

To study the effect of soil-rock's characteristics on the transformation and redistribution of rainwater, a long and continuous monitor of soil-rock moisture was conducted using the time domain reflectometry(TDR) in slope of TaiHang Mountain area, and the spatial-temporal variation of soil-rock moisture was analyzed. Results show that spatial and temporal variations of soil-rock moisture exist in the slope of gneiss region. In the soil-rock layer from surface down to 100 cm, moisture contents distributs from low to high and then to low in vertical profile and the water changs in the same trend in season. In addition, saturated zone instantaneously exists at the soil-gneiss interface in about August. The spatial variation of medium of the soil-rock layer, especially its structure offers the geological condition for the form of instantaneous saturated zone, and the heavy rainfall process offers the hydrological condition. Moreover, soil moisture content of slope before moisture contents and rainfall characteristics such as intensity and duration affects the time that moisture get to or over saturation. Instantaneous saturated zone is good for the formation of preferential flows in lateral and vertical directions. The flows in two directions interacts with each other and prompts the rain infiltration to groundwater.