Abstract
Land evaluation, using a scientific method, is crucial to distinguish the potential and limitations of a given land for specific use in terms of its suitability. The main objective of the study is to assess the land capability and suitability in Jizan Basin in front of Jizan Dam, KSA, and its suitability for agricultural crops using multi-criteria evaluation technique. It covers an area of 460 km(2) and is bounded by the coordinate 42 degrees 57 ' 22 ''-42 degrees 33 ' 28 '' E and 16 degrees 53 ' 12 ''-17 degrees 02 ' 27 '' N. The data of Landsat 8 Operational Land Imager were used to delineate the physiographic units to be a base for the soil taxonomic units. The physiographic units were precisely distinguished using a digital elevation model such as alluvial stands, alluvial fans, playa and valley. Seventy-four soil profiles were studied to represent the soil units. The thematic maps of the soil properties spatial variations were produced using ArcGIS software. The results indicate that most of soils in Jizan Basin are sandy Loam, which had a very noteworthy influence on their physical and chemical characteristics. The values of organic matter, CaCO3, EC and soil pH were low in most of the study area. Soil taxa were classified into aquisalids and calcigypsids. These taxonomic units were potentially evaluated for soil capability classification. The study area classification showed that 32.3% of the total area belonged to C2 class, 40.7% fit in C3 class, while C4, C5 and C6 classes occupied 27%. Soil suitability analysis showed that the olive, barley and alfalfa were highly suitable (S1) with area percentages of 83.3% 63.2% and 60.3%, respectively. From agriculture point of view, the soils near the red sea, west of Jizan Dam, showed the worst soil properties and lowest agricultural land capability.