深层坑渗灌田间单点入渗湿润锋分布特性及拟合模型研究

The wetting front distribution characteristic and the fitting model of single point free infiltration under deep pit irrigation in the field

为了了解深层坑渗灌灌水后湿润锋的分布规律,通过大田原状土上的入渗试验,研究了不同灌水量和不同灌水器管径对不同深度湿润锋水平直径的影响。结果表明：在质地较粗的原状土壤条件下,水平湿润直径的最大值一般出现在深度约30~50 cm之间的土层,灌水器管径200 mm和灌水量30 L/次所达到的灌水效果比较好。此外,建立了具有明确物理意义的深层坑渗灌的单灌水器拟合模型。经过初步评价认为：该模型计算误差在10%以内,计算精度较高,是一种符合深层坑渗灌湿润锋分布规律的函数形式。

In order to understand the distribution of wetting front for deep-pit irrigation,the effects of different irrigation and different emitter diameters on wetting front diameter of different levels and depth is studied with the experiment of infiltration on undisturbed soil.The mainly findings are as follows： The principle of deep-pit irrigation is introduced;In the coarse texture of the original soil,the maximum diameter of horizontal wetting front is usually from about 30 cm to 50 cm in depth,and 200 mm of irrigation device diameter and 30 L of each time irrigation quantity are appropriate.Additionally,the fitting model of a single irrigator is established with clear physical meaning.After preliminary evaluation,the model,with less than 10% error,proves relatively high accuracy in calculation and a kind of appropriate mathematical form for wetting front distribution of deep-pit irrigation,which will provide an important reference for further research on deep-pit irrigation.