Comparing the applicability of some geostatistical methods to predict variability of some soil physical properties

Subject Areas : Farm water management with the aim of improving irrigation management indicators

Jalal  Mahmoudi ¹ (استادیار دانشگاه آزاد اسلامی واحد نور)
fatemeh  Zareian ² (M.Sc student in Rangeland, Islamic Azad University, Nour Branch, Nour, Iran)
Mohamad Reza  Javadi ³ (Assistant professor, Islamic Azad University, Nour Branch, Nour, Iran)
Nazila  khorsandi ⁴ (Assistant professor, Islamic Azad University, Takestan Branch, Iran)

Received: 2011-11-03 Accepted : 2012-04-29 Published : 2012-09-02

Keywords: geostatistics, Kiriging, soil map, Spatial variability,

Abstract :

Reasonable estimation of soil physical properties is very important for optimal management of soil and water resources. Estimation of soil physical properties is usually time consuming and expensive. Geostatistical methods can be used as suitable tools to estimate such properties. In order to analyze spatial variability of soil properties in Dareh Viseh rangelands, a number of 78 soil samples from 0-30cm soil depth were taken and transferred to laboratory. Some soil properties including clay, silt, sand and bulk density were measured in laboratory. After normalizing the data, the semivariograms were obtained and evaluated. The Kriging, inverse distant weighting and radial basis function methods were then evaluated for the obtained data. To compare these methods, the cross validation method was used by statistical parameters of Mean Absolute Error (MAE) and Mean Bias Error (MBE). The results showed that the Kriging method can provide more reseanable predictions for silt, sand and bulk density, while the radial basis function provides better estimate to predict clay content in the study area.