VALIDATION OF ROSETTA PEDOTRANSFER FUNCTION FOR ESTIMATING SOIL MOISTURE RETENTION CURVE OF ARID SOILS IN CENTRAL SAUDI ARABIA

Soil moisture retention curve (SMRC) is needed for many different applications in hydrology, meteorology, ecology and environmental pollution. However, direct measurement of SMRC is time consuming and expensive. Many empirical models have been calibrated to establish a relation between readily available soil properties and SMRC. These models are referred to as pedotransfer functions (PTFs). The objective of this study was to validate the widely used Rosetta PTF with respect to its accuracy and biasness in predicting SMRC of arid soils in central Saudi Arabia. Validation was done by comparing PTF’s estimates to measured SMRC for soil samples that were taken randomly from arid central Saudi Arabia. Accuracy and biasness were quantified using the root mean square error (RMSE) and mean error (ME), respectively. The results show that Rosetta is capable of predicting SMRC of arid soils in Central Saudi Arabia with reasonable accuracy and bias comparable to its performance in other region of the world.