Terrain Analysis as a Base of Soil Productivity in Tushka Basin, Upper Egypt.
Alaa Eldin H. Elnahry, National Authority for Remote Sensing and Space Sciences, 23 Joseph Brows Tito, Elnozha ElGedida, Egypt
One of the largest and most important projects in Egypt is Tushka Project that lies in the western side of Nasser lake, Upper Egypt. The project area covers about 1.5 million feddans, of which about 500,000 feddans will be selected for agricultural uses. The selected area will be irrigated from two sources of water (ground and flooded water). The ground water will be the main water resource for irrigation, followed by, the Nile water during the high flooding seasons. Several attempts were carried out to select the suitable areas for agricultural purposes using the conventional methods. Due to the high cost and time consuming of the ground survey in such an extremely arid land, remote sensing and Geographic Information System (GIS) have to be used for landuse planning in Tushka area. Multi-sensors remotely sensing techniques were applied to map the land resources of the project area. Landsat thematic mapper collaborated with Spot panchromatic imageries were analyzed to define the different mapping units of the area. Data merging techniques were performed to identify the physiographic units of the studied area accurately. Eighteen physiographic units have been recognized i.e. peniplains, footslopes, alkali flats, mesas and buttes ,ridges, chain of barchans ,hills, hilly land ,alluvial fans, plains covered with desert pavement , dry valleys, escarpment, decantation basins, plateau, inclined granitic basement, clusters of basalt and pediment. Physiographic units were integrated with the other parameters for identifying the soil type. Soil productivity classification was applied to evaluate the potentialities of land resources for agriculture. Soil productivity classes range between grade III and VI. On the other hand, the collected surface and ground water samples were analyzed and classified as C1-S1 for the surface water which is suitable for most crops and C3-S1 for the ground water samples which is suitable for salt tolerant crops. Key words: Physiography, soils ,water, productivity,remote sensing and GIS.