ارزيابي يك مدل نيمه تجربي براي تخمين ابعاد پياز رطوبتي و فاصله قطره چكانها

Validating a Semi-Empirical Model for Estimation of Wetted Bulb and Emitter Spacing

The semi-empirical model proposed by Schwartzman and Zur for estimating width and depth of the wetted soil volume under a single emitter was tested by field observations. As the model was developed from data resulted from only two emitter discharges in two soil types, field experiments were conducted in six different soil types and twenty two emitter discharges. A linear regression with zero intercept, was performed to verify the validity of the model. The slope of the line of best fit and its coefficient of determination were 0.99 and 0.98, respectively. Relative error and root of mean squared errors (RMSE) were used to check the discrepancies between observed and estimated values of the maximum diameter of the resulting wetted bulbs. The amount of RMSE, maximum and minimum values of relative errors were 10 cm, 30%, and 0%, respectively. Regarding the statistical results, the validity of the model is confirmed.