An improved cracked soil evaporation model accounting for solar radiation and wind effect

Investigating the evaporation process and corresponding soil moisture redistribution in cracked soils amidst intricate atmospheric conditions poses persistent challenges. In this study, an improved numerical model (Ev-CRACK) is presented for studying water evaporation from cracked soils. Two domains are constructed to model moisture and temperature redistribution within air and soil respectively, which also facilitates to determine the top boundary conditions for next computation step. A homogenization method is utilized to estimate the dispersion of solar radiation across crack surface. To encompass the effect of wind speed, two convective diffusion equations are employed for air domain, and a mass transfer model is integrated to estimate the actual evaporation rate. Two numerical tests are performed to examine the effects of solar radiation and wind speed on cracked soil evaporation process. The results demonstrated that solar radiation changes soil temperature gradient, affects the process of water supply from bottom to evaporation surface, and therefore influences evaporation process. Meanwhile, evaporation rates and the shape of evaporation front are sensitive to wind speed at the beginning of the process when the surface is wet. Furthermore, the presented numerical method provides a benchmark for a satisfactory description of water evaporation from cracked soils.