膜下滴灌对降雨入渗影响研究

A Study on Influence of Drip Irrigation Under Film on Rainfall Infiltration

为深入了解膜下滴灌起垄及覆膜下垫面形式对降雨入渗的影响,以田间原位观测试验为基础,通过对平整裸地、地面灌、无膜滴灌及膜下滴灌4种不同下垫面形式下降雨前后土壤含水率的观测,从入渗量、入渗深度及湿润锋运移速率三方面着重分析了同一天然降雨条件下,起垄及覆膜对降雨入渗的影响效果。结果表明:入渗深度主要受降雨条件影响;起垄的集水作用,可促进湿润锋运移速率,增加入渗量,且降雨历时越短、雨量越大,该作用越明显;地膜的隔水及汇水双重作用,会造成水平方向土水势的显著不均衡性,膜下滴灌入渗量及湿润锋运移速率均小于其他3种下垫面形式,但增加雨量或雨强,则会削弱地膜覆盖引起的差异。

Based on the field observation experiment, this paper analyses the effects of drip irrigation＇s ridging and film on rainfall infiltration from three aspects of infiltration quantity, infiltration depth and wetting front transport rate through observing the soil water content before and after rainfall of four underlying types, including flat bare land, surface irrigation area, drip irrigation area without film, and drip irrigation area under film. The results show that infiltration depth is mainly affected by rainfall conditions; the water collection effects of ridging can increase the transport rate of wetting front, moreover, the shorter the rainfall duration, the greater the rainfall, the more obvious the effect; the dual functions of water resisting and collection of mulching film can cause significant imbalance of soil water potential in horizontal direction; both the infiltration quantity and the wetting front transport rate of the treatment of drip irrigation under film are smaller than those of other three surface forms, however, increasing the rainfall quantity or rainfall intensity will weaken the difference caused by plastic film.