Classification & Evaluation of Soil and Water Quality
at Wadi As-Saul Al-Kabir in Taif, Saudi Arabia

Mohammed Hussein Bagour

Department of Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia
Email: mbagour@kau.edu.sa

Abstract

Natural resources (soils – plants – water) in the Kingdom of Saudi Arabia are continuously changing. Management of these resources and a periodic supply of information about this wide terrain can be obtained by remote sensing. Severe water scarcity is a constraint to agricultural development in arid regions such as Saudi Arabia where the agricultural sector consumes more than 85% of the total amount of available water.

As-Seul Al-Kabir region and its wadi are located in the northwest of Taif city, which is one of the most promising areas in the Kingdom for future sustainable agricultural development. This region does not only constitute one of the oldest agricultural areas in the Kingdom, but it demonstrates sustainable agricultural management factors such as the use of renewable surface water resources. The region experiences warm summer and temperate winter seasons that are suitable for traditional and intensive cultivations. Local Soil survey and evaluation studies are very limited due to the prevailing scarcity of adequate information on soil types and water quality resources in the region. A detailed study was conducted on Wadi As-Seul Al-Kabir soils using imagery in land demarcation integrated with recent satellite digital data. This technology started replacing aerial photography, especially after the introduction of the high resolution technique that made it easy for the researcher to apply such methods for detailed land description. The area was surveyed, classified and evaluated using modern technical application such as vegetation index, principal components, inverse principal components and unsupervised classification. Thirteen soil profiles representing specific soil units in this area were studied. Physical and chemical characters of the land units were obtained along with their agricultural potential. The profiles were placed in there relevant classification, followed by the preparation of detailed maps of the study area. The wells water in Wadi As-Seul Al-Kabir were chemically analyzed by the end of rainy season and the dry-season of one year for their content of salts, pH, soluble salts, anions and cations.