Experimental Study On Water Transporting In Sand

At present, land desertification has become the world's number one ecological problem. With the situation of the shortage of water resources is become stern day by day, how to enhance the water use efficiency as far as possible is become a hot topic in arid and desert areas. The law of water transporting in sand has a guiding role for water conservation in arid regions, but groundwater transport in the sand is less involved in the research areas now.Super absorbent polymer technology is the developed rapidly agricultural chemical water-saving techniques in recent years. This thesis through laboratory experiments, study the law of water transport in the sand and the insurance on water transport in sand when layering SAP in sand. The main results and conclusions are as follows:1. Water transport in soil could be described by model =(?)θ/(?)t=(?)/(?)x[D(θ)(?)θ/(?)x],θis the water content, D(θ) is the diffusivity, and x is the distance.2. The maximum height of aquifer and cumulative evaporation increased with the amount of injected water increases. The inject-method of water influenced the maximum height when injecting the same amount water. The height of injecting water vicinity the SAP is lower than injecting water apart from SAP. Super absorbent polymer can prevent water vertical infiltrating.3. During the vertical movement, the relationship between cumulative evaporation and time could be described by model E=atb (a, b as parameters), the relationship between wetting front and time could be correlated by cubic or 4th polynomial.4. The surface evaporation of free water can be obtained through evaporator conversion method. The relationship between cumulative evaporation and time of small area water evaporation can be simulated by one-dimensional diffusion model of saturated water vapor.