不同地面处理下的降雨入渗规律研究

A Study on Rainfall Infiltration Law Under Different Ground Treatments

近年来,膜下滴灌等节水灌溉技术的实施提高了水分利用效率,但膜下滴灌的起垄和覆膜的处理在一定程度上改变了农田下垫面条件,降雨的入渗过程会受到一定影响。为了分析膜下滴灌的覆膜及起垄对降雨入渗过程的影响,试验选取下垫面处理、降雨强度、土壤初始含水量3个影响因素,进行了遮雨棚内的人工降雨测坑试验。试验数据分析结果表明:降雨强度对降雨入渗量及入渗深度影响最大;不同下垫面处理中,平整裸地的入渗量及入渗深度最大,起垄次之,覆膜及起垄最小。在一定的降雨强度范围内,垄沟的集雨作用随着雨强的增加而增加,沟内的入渗量增加显著;在起垄及覆膜起垄条件下,膜上水分由于膜的不透水作用和垄沟的集雨作用,分别是膜边和沟中的降雨入渗量最大。当雨强继续增加时,垄沟的集雨作用被削弱,但膜的汇流作用仍然存在,覆膜区域下方的土壤水分都是由膜边的土壤水分经过侧向运移达到,土壤水分的二维入渗过程十分显著。

In recent years,the implementation of water-saving irrigation improves water use efficiency,but the treatment of film mulching and ridge changes the farmland surface conditions,and the infiltration process of rainfall will be affected. In order to analyze the influence of film and ridging of drip irrigation on rainfall infiltration,three factors,including surface treatment,rainfall intensity and initial soil moisture content,were selected and artificial rainfall pit experiments were conducted in a rain shelter. The experimental data analysis results show that the rainfall intensity has the largest influence on rainfall infiltration and infiltration depth; among different surface treatment,infiltration capacity and infiltration depth are the largest under flat bare land,followed by ridging,mulching with ridging. In a certain rain intensity range,the rain collection effect of furrow increases with the increase of rainfall,the infiltration in ditch increases significantly; under ridging with film conditions,due to the rain collection effect of furrow and the impermeable effect of membrane,the rainfall infiltration in the film side and ditch is the largest; when the rain intensity continues to increase,the rain collection effect of furrow is weakened,but the confluence effect of film still exists,the soil moisture of the film-covered area is due to the soil water at the film edge through lateral migration,and the two-dimensional soil water infiltration process is very significant.