A Physiographic Study and Land Evaluation of the Soils of some Eastern Desert Wadies , Egypt, Using Landsat Images Interpretation

Abstract

The soils of both wadies Qift and Zeidun are considered one of the promising parts of Eastern Desert, due to a wide area of arable land and the high potential of ground water. Additionally, the area is considered a good model for representing many of the landscape features, in the Eastern Desert. So this study aims to identify the different physiographic units including soil developed in this area by interpretation landsat ETM 8 image, as to determine soil suitability class that have closely relationships with physiographic characteristics. This technique plays an important role for utilizing these scanned promising areas. The area under consideration lies between latitudes (26o 00ˉ) and (25o 50ˉ) North and longitude (32o 45ˉ) and (33o 05ˉ) East and covered by Landsat TM8 image bands 2,4 and 7. The data obtained show that the studied area were identified physiographically, as:(1) Rubble Terraces (stony pediment soils), old alluvial terraces (high & low),young alluvial plain terraces (high & low) , fan and outwash plane, wadies (wadi bottom and wadi plain) and Miscellaneous land types (Rock land). According to the morphological features and analytical data, the soils developed on the main physiographic units are classified till the family level into: A: Aridisols , soil families are : 1-Typic Calcigypsids, sandy skeletal, mixed , hyper thermic, (old and young alluvial terraces(high & low) and wadi bottom soils.2- Typic Calcigypsids, loamy skeletal, mixed ,hyper thermic at the soils of old alluvial terraces (high) and wadi bottom soils. 3- Lithic Haplocalcids, loamy skeletal, mixed , hyper thermic, (Rubble terraces stony pediment). 4- Typic Haplocalcids, sandy skeletal, mixed, hyper thermic at old and young alluvial terraces (low) and wadi bottom soils. 5- Typic Haplocalcids, loamy skeletal (young high terraces) and wadi bottom. B: Entisols included: 1- Typic Torripsamments, sandy skeletal, mixed, hyper thermic young alluvial terraces (low), fan and outwash plain. 2- Typic Torriorthents, sandy, mixed, hyper thermic (wadi plain soils). The soil evaluation results of the studied soils revealed that the soils of wadi bottom and wadi plain soils currently marginally suitable lands (S3) and moderately suitable (S2). Fan and out wash plain and some soil of low young alluvial terraces currently are marginally suitable lands (S3). Whereas, Rubble terraces stony pediment soils, and some soil of old alluvial terraces, and high young alluvial terraces are currently not suitable (N1). In addition, the limiting factors for soil productivity are topography, soil texture effective, soil depth, CaCO3 content, salinity and alkalinity. Potential suitability was identified after required land improvements and reveal that all the studied soils are placed between marginally and moderate suitable (S3 & S2). The limiting factors for soil productively are soil texture and soil depth.