Mapping Soil Organic Carbon Using IRS-AWIFS Satellite Imagery (Case Study: Dehaghan Rangeland, Isfahan, IRAN)

Document Type: Research and Full Length Article

Authors

1 Range Management Isfahan University of Technology

2 Isfahan University of Technology

3 Geography & Rural Planning University of Tarbiat Modares

Abstract

Soil organic matter has positive consequences eht rof quality and productivity
of soil and also environment, agricultural and biological sustainability and conservation of
biodiversity and soil. Organic matter plays an important role in the physical and chemical
processes of soil and thus, it is of a great effect on the spectral characteristics of soil. This
study was done in order to develop the mapping surface of soil Organic Carbon (OC) of
various land uses, particularly rangelands using remote sensing technology in Dehaghan in
the south of Isfahan. The data of IRS-P6 and AWIFS satellites with 49 ground control
points and accuracy less than 0.3 pixels were recorded. Stratified random sampling method
was used. Soil samples were collected from the depth of 0-15 cm at each point. Bulk
density of soil samples was determined according to Hunk method and OC% was
computed by Walky-Black method. For the preparation of land use map and False Color
Composite (FCC), the supervised classification was conducted using maximum likelihood
algorithm and Optimized Index Factor (OIF). In order to map the surface soil OC, the
multivariate regression model was fitted using band 2 (red band) as the dependent variable.
Red band had a relationship with surface soil OC in the study area. Relationship of the red
band and surface soil OC content was negative. IRS-P6 and AWIFS satellite images
according to the cover of spectral and spatial resolution were considered as a useful
method for the preparation of land use map and the map of surface soil OC levels in the
study area.

Keywords