Prediction of Field Water Infiltration Based on Soil Physical Characteristics

Abstract

A field study was conducted in the agricultural area located at the town of Al – Muqdadiya- Diyala province (Longitudes 44 – 46 East, Latitudes 33 – 35 North). The purpose of the study is to determine, the most effective soil properties on the prediction of field infiltration. Measurements were achieved in six different sites in duding their soil textures and other soil characteristics. Infiltration was measured by using a double ring infiltrometer. A stepwise regression method was applied in order to determine the best field infiltration rating equation. Mean difference confidence interval approach was used to compare the infiltration values predicted by models with these values measured by field data. Additionally, the Bland – Altman approach was used to plot the agreement between the two methods values. Results showed that the predicted of field infiltration rate (i) was depend on laboratory infiltration rate (Li), initial soil volumetric moisture content volumetric moisture elementary soil (Өmi), soil moisture at content 33 kPa (Ө33),and 1500 kPa(Ө1500) according to the fallowing linear regression model. i = - 0.04177 + 0.53303 Li + 0.00210 Өmi + 0.15584 Ө33 + - 0.10032 Ө1500 with R2 = 1.00 and RMSE = 0.0 can be adopted strongly in predicting infiltration field results and also the results showed that the predicted infiltration values increase and decrease by measured field infiltration rate.