LAND SUITABILITY ASSESSMENT FOR SOME SPECIFIC CROPS USING REMOTE SENESING AND GIS IN EL-QAA PLAIN, SOUTH SINAI, EGYPT.

Abstract

In Egypt, the excessive population growth and the lack of food security were the guide to increase production in unit area, expand the cultivated land horizontally, and to utilize the land with respect to its potentiality in an appropriate way. Therefore, this study aims to integrate soil qualities (or characteristics) with remote sensing data and Digital Elevation Model (DEM) into a Geographic Information System (GIS) to produce a database for the land resources and the soil map, and assess the current and potential suitability of some specific crops in El-Qaa plain, South Sinai, Egypt. Two SPOT5 images were classified using unsupervised classification technique. The base map of the study area was used in the field to check, confirm, correct and modify the physiographic mapping unit boundaries. Four sample areas were selected. 26 soil profiles were taken to represent the different mapping units in the study area. Morphological description and soil sampling were collected for laboratory analyses. The physiographic units were classified into subgroup level on the basis of the key to soil taxonomy. the results show that soils in the study area include: sand sheet (Low, moderate, and high) classified as Typic Torripsamments and Typic Haplosalids, Bajada classified as Typic Torripsamments and Sodic Haplocalcids, Basin classified as Typic Torriorthents, Wadi classified as Typic Torripsamments and Sodic Haplocalcids, Dry sabkhas classified as Typic Aquisalids, and Wet sabkhas classified as Sodic Psammaquents. The main land qualities of the different mapping units were selected and crop requirements of 21 crops were rated and matched to obtain the current and potential land suitability. The suitability of the selected crops currently not suitable in the different mapping units. The main limiting factors are texture, salinity and alkalinity, nutrient availability and calcium carbonate content, only in sabkhas added flooding, drainage, and soil depth. The potential suitability in the different mapping units refers that soils can be highly (S1), moderately (S2), and marginally (S3) suitable with a proper management practices and fertilization, and can not be suitable due to soil texture in all mapping units except in sabkhas where the limiting factors are texture, salinity and alkalinity, flooding, drainage, and soil depth which can not be enhanced in the near future. The results obtained can be employed by landuse planners (decision makers) to select areas suitable for the selected crops production.