滴灌条件下砂壤土水分运动规律研究

采用多通道土壤水分自动测定系统,对风干砂壤土在滴灌条件下的水分入渗和水分再分布过程进行了模拟测定试验。根据测定结果,分析了在滴灌条件下湿润峰的运移速率、特征点的土壤含水率变化过程、湿润体内土壤水分的分布以及停止灌水后湿润体内水分的再分布等土壤水分运动特征。揭示了在点源供水条件下,湿润体内土壤含水率的分布从中心向外逐渐减小,含水率剖面具有三角形形状特征。供水停止后土壤水分再分布过程中,土壤湿润峰面不断向外部推移,湿润层土壤含水量开始有所增加,后期湿润体内的土壤含水量普遍降低,高含水区逐渐下移,最后达到相对稳定。

The Laws of Soil Water Movement under the Drip Irrigation

Adopting muctipassway soil water automatic determine system,under the drip irrigation condition water infiltration and redistribution are simulated and determined for air dried sandy soil.According to the determined result,the text analyze characteristics of soil water movement,such as the increased rate of the wetting front,the course of soil water content movement of the characteristic point,soil water distribution during irrigation and soil water redistribution after irrigation in wetting region.The result of test show that soil water content distribution is reduced gradually from center outward,and the water content section possesses the characteristics of triangular form under the point source infiltration.In the course of the soil water redistributions after stopping irrigating,wetting front is passing to the outside constantly,and the soil water content of wetting layer increase in the beginning,and soil water content in the wetting region is generally reduced on later stage,and the region where the soil water is higher shifts down gradually,and soil water content is relatively stable to reach finally.