石子和秸秆覆盖条件下降雨水量转化特征试验研究

通过人工模拟降雨，利用蒸渗仪、TDR(时域反射仪)和翻斗式自计流量测定仪，对石子和秸秆覆盖条件下的土壤水分动态变化、地下渗流过程进行了连续监测，并对不同下垫面条件下水量转化的变异特征进行了分析。结果表明：(1)不同下垫面条件下土壤表层的水分变异不大，而土壤深层的水分变异较大，这主要是由于覆盖降低了雨滴对土壤表层结构的破坏程度，以及石子在地表构建了许多个微型拦水坝，从而促进了土壤水分的快速下渗；(2)覆盖具有增加地下渗流的效果，特别是坡地上覆盖小石子在防止土壤侵蚀，增加地下渗流方面效果最为显著，地下渗流系数达到了37.44％；(3)小石子覆盖有利于山地降水资源的高效转化利用，其中在水平地上进行覆盖处理有助于降水资源的就地利用，而在“上覆土壤、下伏岩石”为结构特征的坡地上进行覆盖处理有助于坡地岩土界面渗流的产生，而从提高降水资源的异地利用率。

Field experiment on transfer of rainfall under the condition of ground surface mulched with small stones or stalk

The surface runoff and movement of soil water and groundwater under the condition of ground surface mulched with small stones or stalk were monitored continuously by using lysimeter,time domain reflectometry and tilting bucket flow meter in the whole process of an artificial rainfall event.The analysis on the transfer characteristics of water shows that: 1.The water contents in topsoil layer were approximately the same for different mulching materials,but vary remarkably in deep soil layer since the mulch mitigates the damage of soil structure due to raindrop and many micro-dams formed by small stones resulted in improvement of the infiltration of water.2.Mulch was helpful to prevent soil from erosion and enhance the effect of infiltration.3.The ground surface mulched with small stones was advantageous to the high efficiency utilization of rainwater in mountainous area.Especially mulching the slope,characterized by a shallow soil layer and a deep weathering layer of rocks,promoted the ground water flow and made it possible for rainwater used inother areas.