负压自动补给灌溉原理及可行性试验研究

本文提出了一种新型的负压节水灌溉技术，系统在水源高程低于灌水器高程(供水水头为负值)情况下，无需动力加压设备，自动补给实现灌溉作业。理论分析了负压灌溉的基本原理。试验研究了水源与灌水器间不同高程差(H)对灌水效果的影响，试验结果表明：累计入渗量、最大水平和垂直湿润距离随时间呈幂函数变化关系，随高程差呈指数变化关系，相关系数均非常高；湿润锋开始时运移较快，等时间线较稀疏，后来运移变慢，等时间线变密，湿润体近似为椭球体。理论上和试验均说明只要灌水器与水源的高差不超过一定范围，负压灌溉是可行的。

Principle of negative pressure difference irrigation system and feasibility experimental study

A new technology namely negative pressure difference irrigation based on principle of soil water dynamics is developed. By using this technology the irrigation water can be automatically supplied from the source tank lower than the irrigated field without pumping system. Laboratory experiments are arranged to verify the feasibility of this technology and study the influence of elevation difference between water source and emitter on the movement of water in soil. The results show that this irrigation method is feasible if the elevation difference is within a specific range. The relationships between time and cumulative infiltration, maximum horizontal and vertical wetted distance are power functions. The relationships between elevation differences and cumulative infiltration, maximum horizontal and vertical wetted distances are exponential functions. The wetting front advances quickly at first, but will be slowing down as time going on.