An analytical solution of nonsteady evaporation from bare soils with shallow ground water table

摘要: Evaporation from bare soils plays a significant role in hydrological cycle, particularly arid and semi-arid regions. In such areas, large amount of the water that enters into soil returns to atmosphere through evaporation. these regions, there are some areas with shallow groundwater table, evaporating considerable accumulating salts at upper parts profile. One major difficulty for accurate estimate evaporation field conditions arises lack simple function less needed input parameters account losses soil-water balance models. The main purpose this study was develop verify an analytical solution one-dimensional non-steady upward flow ground table minimum data. Consequently, developed based on Richards' equation initial boundary governing process. solution, instant surface can be estimated as drawdown, impermeable layer depth, hydraulic functions. is parametric closed form van Genuchten retention curve. Some lysimetric experiments packed Silty Clay, Clay Loam Sandy were carried out evaluate solutions. results indicate reasonable agreement between collected data theoretical scheme. seems promising different types, requiring only few accessible parameters. However, small discrepancies attributed side gap shrinkaged soil, vapor phase, experimental errors most importantly collapse macropores resulting packing.