LAND AND WATER RESOURCES ASSESSMENT FOR SUSTAINABLE AGRICULTURAL DEVELOPMENT IN EL-KHARGA OASES BY USING REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM

Abstract

El-Kharga Oases, New Valley governorate, Egypt was selected as a study area. It is located between latitudes 25o15ʽ and 26o05 ʽN. and longitudes 30o05 ʽ and 30o45 ʽE., having an area of 18813.8 km2. The aim of this investigation is to study the characteristics of soils and groundwater in this area for evaluating their capability and suitability for growing main crops using RS and GIS. The obtained geomorphic map showed that, the area comprises three distinct geomorphic units namely, high land (28.8%), plateau (39.3%) and depression floor (31.9%). The depression floor of various origin and almost flat areas is the main landforms and suitable units for developmental plans. The soils were classified up to sub great group level on the basis of Soil Survey Staff (2014). Land evaluation was conducted using a model depend on the bases of Sys & Verheye index and land suitability for irrigated agriculture. Accordingly, the current capability of the studied soils was classified as: fair (III) for about 45% from the studied area, poor IV (about 50%) and very poor N for the remaining area. By executing a suitable improvement practices, these classes could be developed to the following three potential capability classes; good (II), fair (III) and poor (IV). Also, soil suitability for growing specific field, vegetable and fruit crops were evaluated in the studied geomorphic units. The quality evaluation of ground water resources showed that, the pH values ranged from ultra-acid (3.47 north El-Kharga) to slightly alkaline (7.83 in Max Qibly). The salinity of ground water changed from 0.48 to 119 dS m-1 indicating non-saline to very extremely saline, TDS values varied from 307.2 to 71424 ppm (fresh, brackish, to extremely saline water). Total hardness varied from soft to very hard.