Analysis of the surface layer properties influence on the actual evaporation and efficiency of the soil cover to combat desertification

Abstract

Global warming is one of the most alarming environmental issues worldwide, disrupting the natural water cycle and exacerbating desertification. Proper understanding of the soil-atmosphere fluxes (mainly evaporation) is crucial. Most existing studies focus on the evaporation stages and the governing mechanisms. However, an environmental-friendly simple method to control the actual evaporation flux in arid regions is in great need to efficiently combat desertification. Through this paper, a simple design concept for a soil cover to maximize water conservation is proposed based on a series of 1-D column tests. It was found that using a coarse cover layer, the head gradient is oriented towards the bottom layer, disrupting the water supply to the surface and limiting the evaporation flux. While a fine cover induces a reversed head gradient oriented towards the cover layer, ejecting the water from the bottom to the top and resulting in a higher water loss. The proposed cover design includes two criteria: a) relative retention potential. b) relative cover thickness. The water storage capability can be maximized by applying a proper cover to minimize the criteria values.