地下滴灌湿润比计算方法探讨

Research on the Calculation Method of the Wetted Percentage of Subsurface Drip Irrigation

最近几年地下滴灌在国内推广迅速,但其工程设计仍按地表滴灌模式进行,一定程度上阻碍了其应用。湿润比是微灌系统设计的重要参数之一,在前人研究的基础上,对地下滴灌湿润比计算方法进行了理论推导,给出了理论计算公式,并进行了相关误差分析。认为：地下滴灌湿润比计算公式与地表滴灌类似,但与计划湿润深度、灌水器埋深等参数相关;继续使用地表滴灌湿润比计算公式会产生误差,误差大小与计划湿润深度和湿润体形状密切相关;只有在一定取值范围内才可继续沿用20~30 cm深处土层的湿润面积来计算湿润比。

Subsurface drip irrigation has been developed very fast in China in recent years,but its design is still based on the drip irrigation model,which has to some extent.hindered application Wetting proportion is one of the important parameters of the micro-irrigation system design.Based on previous studies,a theoretical research on wetted percentage of subsurface drip irrigation design is carried out in this paper.The computation formula has been got and its relevant error analysis has also been made.The results show that the formula of the wetting proportion of the subsurface drip irrigation is similar to that of the drip irrigation,but the value is related to the scheming wetted soil layer depth and buried depth of the emitter and so on.The errors will be produced when the computation formula of drip irrigation model is still applied to the subsurface and the value is related to the scheming wetted soil layer depth and shape of wetting soil.The wetting area of 20~30 cm deep soil layer may also be used to calculate the wetting proportion,but only within the range of some fixed value.