Desertification hazards in the middle zone of Wadi Fatimah, West Saudi Arabia

Abstract

This research aims at determining and analysing the causes and consequences of desertification in the middle zone of Wadi Fatimah using satellite images, climatic data, and topographic maps. The climatic parameters such as temperature, rainfall, and global reference evapotranspiration (ET0) indicated common severe arid conditions in the study area. The CORONA images acquired in 1967 and 1979 along with the topographic map of 1971 helped define the initial morphologic features and anthropogenic regimes. Analysing the various spatial datasets implied that the inappropriate management of water resources has resulted in changes in the anthropogenic regimes in the middle zone of Wadi Fatimah. These changes have triggered a chain of desertification processes such as degradation of the vegetation biomass and wind activities. These processes have transformed 15.3 km2 of agricultural farms into abandoned lands. Nineteen km2 of bushes have disappeared as well. The degradation of both agricultural and natural vegetation has exposed soils to intense wind erosion that detaches, transports and deposits sand in areas of low elevations. Accordingly, sand accumulations have massively expanded from 16.4 km2, as monitored by 1967 CORONA images, to 40.8 km2, as monitored by SPOT in 2013. This research emphasises that the middle zone of Wadi Fatimah has been experiencing remarkable changes in its morphologic and environmental characteristics in response to serious desertification processes. These processes are strongly linked to many anthropogenic interventions. It became a necessity, then, to redefine, study and assess the various anthropogenic parameters and their relative roles in desertification processes to combat desertification hazards and enhance sustainable environmental context in the middle zone of Wadi Fatimah.