Simulation And Experiment For The Water And Salt Evapotranspiration In The Soil

The pollution caused by oil extraction wastewater to the environment has gradually caused the attention of environmentalists,high salinity oil extraction wastewater will also cause soil salinization and bring great harm to the environment.However,due to the lack of the standard data and instructional experiment methods,the environmental protection department can't set up formal system of desalination processing.This topic is about application of Hydrus-1D for simulating water and salt in the soil on the basis of experiment.The water content of soil samples is measured through soil-column experiment and salt content is simulated with Hydrus-1D according to the experiment results and model parameters.There are three groups in the experiment,each group has two soil columns,and the bottoms of soil columns are immersed in 5%NaCl solution and 10%NaCl solution respectively for 30 days.The first group is given continuous light from 55 w incandescent lamp for 30 days;The second group is given the artificial rainfall for 4 mm,2 mm,2 mm respectively in the second day,10th day and19th day,and there is no light for 4 hours during the rainfall time;The third group is to continue the second group for another 30 days without light.Application of Hydrus-1D for simulating water and salt in the soil determines the boundary condition and initial condition of the simulation,and the model parameters are corrected based on the experimental data of water content and salt content in the thirtieth day.The basic soil water movement equation are Richards equation and van Genuchten-Mualem model,and the basic soil soil movement equation is advection-dispersion equation for simulating;upper boundary condition is atmospheric boundary,lower boundary is constant flux boundary;the initial water content is 4.5%,the initial salt content is 0.2716mg/cm³ for the first two models.The model parameters have adaptability and representative for simulating water and salt in the soil.