Ismail. M, El-Shemy, A. S. A, and Shoman, M. M.( 2010). Land evaluation of physiographic units in some wadies in the eastern desert of Egypt using remote sensing and geographic information systemJ. Biol. Chem. Environ. Sci., 2010, 5(1), 19-42
Abstract: Visual interpretation of Landsat-7 ETM-7 bands 4, 3 and 2 was depending on many elements such as tone, shape, size, pattern, texture, shadow, and association. The interpretation was done to extract all important landscape. A physiographic analysis using visual interpretation was carried out to delineate the different physiographic units of the studied area. The main physiographic units in the studied area extracted from visual interpretation and spectral classification are defined in soil maps and could be categorized into 7 units. i.e. Piedmont, Alluvial Terraces, Alluvial fans, Bajadas, Wadies, Coastal braided deltas and Marine sediments. According to Soil Taxonomy System the studied area could be classified into two orders (Aridisols and Entisols), five suborders (Salids, Gypsids, Calcids, Fluvents and Orthents), and ten soil families. Six soil families belong to Aridisols and four Entisol families were identified. Current land suitability refers to the suitability for a defined use of land in its present condition, without major improvements. Currently include two orders {suitable (S) and not suitable (N)}, two classes {marginally suitable (S3) and currently not suitable (N1)}, two subclasses (N1sn and N1wsn) and five units (S3sn-1, S3sn-2, N1tsn-1, N1tsn-2 and N1tsn-3) Potential suitability term refers to the suitability of units, for a defined use, in their conditions at some future data, after specified major improvements have been completed where necessary (FAO, 1976). Land improvements are activities which cause beneficial 20 LAND EVALUATION OF PHYSIOGRAPHIC UNITS IN SOME changes in the qualities of the land itself. The future land improvements are required to correct or reduce the severity of limitations exiting in the area under consideration. Such as a) leveling of undulating surface soils, construction of good drainage systems to lower the saline ground water table in the soils of marine sediments, leaching of salinity and reclamation of alkalinity existing in the soils of coastal braided delta, alluvial fans, piedmont and marine sediments, application of chemical and organic fertilizers, green manure and soil conditioners to increase soil fertility to improve the physical and chemical soil characteristics and application of modern irrigation systems, such as drip and sprinkler to save irrigation water. Potential suitability of the studied soils indicated the existing of two orders (S and N), three classes (S2, S3 and N1), three subclasses (S2s, S3s and N1ws) and three units (S3s-1, S3s-2 and S3s-3)
Keywords: (satellite data, GIS, Eastern Desert Area, Soil Taxonomy System Land evaluation .)
