Study on Distribution and Change Laws of Soil Water Content due to Evaporation

Desiccation cracks of soil are resulted from evaporation.It makes soil broken and the strength reduced.The distribution characteristics and change laws of soil moisture content due to evaporation are obtained by numerical simulation.The higher the temperature and the longer the evaporation time,the faster the rate of water loses and the deeper the influencing depth is.The soil volumetric water content-depth relationship is closely related to the SWCC,groundwater level and duration of evaporation.When the ground water level is low or the duration of evaporation is short,the deep soil water hardly transports to the surface soil and the residual steady state of surface soil can be achieved.The relation curve of soil volumetric water content and depth is similar to the SWCC.When the ground water level is high or the duration of evaporation is long,the deep soil moisture can be easily transported to the surface soil and the residual steady state of surface soil cannot be achieved.The relation curve of soil water content and depth shows negative exponential function.