GEOMATICS BASED SOIL MAPPING OF THE EASTERN DESERT PART OF SOHAG GOVERNORATE, EGYPT

Abstract

The aim of this study is to apply the powerful capabilities of advanced remote sensing and GIS techniques to identify and characterize the main physiographic units of some soils of the Eastern Desert Part of Sohag Governorate. A physiographic analysis using visual interpretation of false colour composite (FCC) of Landsat ETM images was carried out to delineate the different physiographic units of the studied area which accurately defined by the Digital Elevation Model (DEM) which generated from the Shuttle Radar Topographic Mission (SRTM). Twelve soil profiles were collected and examined to represent the soils of the studied area. The soils of the studied area are slightly to highly saline (EC values ranged from 3.83 to 10.67 dS/m). Soil texture is mostly sandy to loamy sand. Soil pH values ranged from 7.83 to 8.45. Organic carbon content is very low with a maximum value of 0.35%. Regarding the CEC, it varied from 2.68 to 4.76 cmole+/kg and the CaCO3 ranged from 3.81 to 17.68 %. The soils were classified as Typic Haplocalcids, Typic Torripsamment and Typic Torriorthents. The major landforms of the studied area were described as Wadi Bottom (WB), Bajada (B), Alluvial Fans (AF), Tableland (T), Gently Undulating Sand Sheet (GUS) and Undulating Sand Sheet (US).The data revealed that current capability of soils is moderately suitable (S2), marginally suitable (S3) and temporary not suitable (N1). The major limiting factors were texture, topography and salinity. With the application of some scientific and technical improvements, the limiting factors could be mitigated to attain the potential capability of the soils of the study area.