Soil moisture estimation using Digital Elevation Model (DEM)

Subject Areas : Geospatial systems development

Hassan Rezaii Moghadam ¹ , Mohsen Hosseinalizadeh ² , Nahed Berdi Sheikh ³ , Roya Jafari ⁴

1 - MSc. Student of Watershed Management, Gorgan University of Agricultural Sciences & Natural Resources
2 - Assis. Prof. College of Range Land and Watershed Management, Gorgan University of Agricultural Sciences & Natural Resources
3 - Assoc. Prof. College of Range Land and Watershed Management, Gorgan University of Agricultural Sciences & Natural Resources
4 - MSc. Student of Watershed Management, Gorgan University of Agricultural Sciences & Natural Resources

Received: 2014-12-09 Accepted : 2015-07-23 Published : 2015-11-22

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Abstract :

This study was carried out in the western catchment of the Behzisty Township in Gorgan, Golestan province in order to develop the regression models of soil moisture. In this study, the desired measurements were made in 18 locations using TDR during 6 running days after a relatively intense rainfall event at different depths of soil. The digital elevation model was prepared from UltraCam images taken in 2014 with the pixel size of 1×1 m in order to estimate the terrain properties. Finally, the regression model was developed with respect to these characteristics and soil moisture. The results showed that important terrain characteristics which are greatly associated with soil moisture are horizontal curvature, slope, aspect and wetness index in the regression model. These results suggest that the diversion of material flow has controlled the amount of water in the soil, slope aspect and soil moisture. The results showed that the developed regression models can forecast at least 44 to 60% of the total variations of soil moisture in the watershed scale.