点源滴灌地表积水区半径运移模型分析

Analysis of Soil Surface Ponding Radius Movement Model under Point Source Drip Irrigation

为了探明滴灌地表积水区的运移机理以水量平衡原理和考斯加科夫入渗公式为基础,建立了描述点源滴灌地表积水区半径运移的数学模型,并在沙壤土和中壤土上进行了点源滴灌地表积水区实验验证,以此对模型中各参数的作用做了理论分析。结果表明,地表积水区半径随积水时间呈幂函数增大;土壤入渗指数决定着积水区半径的运移速度,它们之间呈正相关关系;滴头流量决定着积水区出现时间,它们之间呈负相关关系;所建立的地表积水区半径运移模型适用于评价积水区的运移阶段。该模型能为理解地表积水区运移机理提供帮助。

A model is developed based on the principle of water balance and the Kostiakov infiltration equation to study the mechanism of the soil surface ponding movement under the drip irrigation with point source.The drip irrigation experiments for demonstrating surface ponding are carried out on sandy loam and loam to analyze the relations between the model parameters and the surface ponding movement.The results indicate that the radius of the soil surface ponding increases along with time in power function;the moving speed of the surface ponding is subject to the soil infiltration index in a positive correlation relation;the initial surface ponding is subject to the drip flow rate in a negative correlation relation;the developed model is valuable for evaluating the surface ponding movement.The model is helpful to understand the soil surface ponding movement mechanism.