Experimental study of moisture evaporation process with different soil characteristics

Abstract

Evaporation of water from soils induces soil cracking, salinization and degradation, especially in arid irrigated areas. The factors that influence water evaporation from soil includes external type, referring to atmospheric conditions and interior type, covering surficial soil characteristics and water content conditions. In spite of the numerous assessment that have been made on the influence of atmospheric conditions and soil characteristics on evaporation of moisture from soils, many aspects still require further investigation due to soil complexity. In this study, laboratory-based evaporation tests were performed on clayey soil and three kinds of quartzite sands of different particle sizes using the same environmental conditions. Three different tests were performed on slurry samples to evaluate the effects of soil characteristics on its free water evaporation process at room temperature (20-22°C) and relative humidity (50 ± 2%) conditions: soil thickness, particle size of mixing sand and mixing sands ratio. It is shown that larger soil sample thicknesses accelerate water evaporation rate and extend the constant evaporation rate stage. Higher sand mix proportions lead to larger evaporation area and soil porosity, allowing higher evaporation rate and longer duration of the first stage and the starting of the falling rate stage at lower water content. However, soil particle size was not found to have a significant impact on evaporation rate on per unit weight of added soil basis.

Effect of vapour transport on soil evaporation under different soil textures and water table depths in an arid area of Northwest China

“…To solve this issue, many researchers proposed to use the fully coupled model of liquid–heat–vapour dynamic processes for accurately capturing water transport driven by the diurnal heating and cooling of the soil surface and the consequent thermal expansion and contraction of soil air (Brutsaert & Parlange, 1998; Cahill & Parlange, 1998). For the coupled models, soil physical, thermal and hydraulic characteristics significantly affect soil–atmosphere interaction process in arid and semiarid areas (An et al, 2019; Cui et al, 2005; Cui & Zornberg, 2008; Saito et al, 2006). Usually, the unsaturated hydraulic conductivity at low water content is difficult to measure (Sakai et al, 2009).…”