Geomorphology and pedology of south western area of Toshka, Egypt, using RS and GIS techniques [electronic resource].

Includes references.

The aim of this research is to identify the geomorphological features and study the soil characteristics and classification of the south western area of Toshka, Egypt. For these purposes and for producing the maps of the study area, the remote sensing (RS) and GIS techniques were used. According to the RS and GIS works, five main geomorphic unites with different subunits are recognized. These units are 1) Plain sandstone terraces (with three subunits i.e. low, medium and high terraces); 2) Depression (with three subunits i.e. plain sandstone, deposited hill and eroded karstified hill depressions); 3) Residual hills (with six subunits i.e. deposited back-slopes and foot slopes as well as eroded karstified top, summit, back-slopes and foot-slopes hills); 4) Sand ~heets (with three subunits i.e. low, medium and high); and 5) Rock mesas (with four subunits i.e. plain sandstone, deposited hills, eroded karstified hills and sand sheet mesas). Thirteen selected soil profiles representing the geomorphic unites were morphologically described and soil samples were collected according to the vertical variations. These samples were analyzed for their physical and chemical characteristics. The elevation of the studied area is between 194 and 256 m above sea level. The study area has different topography (i.e. almost flat, nearly level and undulated to sloping). The soil profiles are moderately deep to. f:Jeep with well drainage status. They have mainly sandy texture with common fine to coarse gravels and/or fragments. The main soil structure is weak fine granular to medium sub angular blocky. The consistence is soft to hard when dry and friable when moist. The main hue notation of the soils has reddish color mainly between 2.5YR to 10YR. The soils are slightly to moderately saline having weak alkaline reaction. The soils have almost low to medium calcium carbonate contents. Organic matter content (OM) is very low and decreased generally with depth. The cation exchange capacity (CEC) is mainly correlated with the fine fractions and organic matter contents. The exchangeable sodium percentage (ESP) is very high making sodicity effect in the most of profile layers. The studied soils haven't any diagnostic horizons and therefore, they are classified under Entisols order up to sub-great group's level according to Soil Survey Staff (2010). GIS works

Summary in Arabic.

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