The North China Plain Farmland Layer Soil Water Movement Of Experiment And Numerical Simulation

This paper is based on the national973plan-climate change to the influence of thedrought and flood disaster and risk assessment,（2010CB951102）. According to theunsaturated soil water movement basic theory of soil water dynamics, this paper establishedthe mathematical model of one-dimensional layered soil water, and deploy the relatedexperimental equipment, such as neutron probe, negative pressure meter and so on. And themodel is verified by the actual experimental data. Besides, under the condition of climatechanging and evapotranspiration increasing, this paper makes a preliminary forecast andanalysis on soil water movement of corresponding period. The main results and conclusionsare as follows:1、In the experiment area, we deploy mercury negative pressure meter to measurenegative pressure. We also deploy the ancillary facilities of neutron probe, which is designedand installed by ourselves, and use neutron probe to measure soil water content.2、 Through the laboratory experimental, we measured the soil water movementparameters of silt loam and clay. These parameters conclude soil water characteristic curve,specific water capacity and hydraulic conductivity. Meanwhile, we use eddy covariancetechnique to measure the field evapotranspiration.3、This paper established the mathematical model of one-dimensional layered soil water.Using this model, this paper simulated one-dimensional layered of soil water movementprocess of summer maize evapotranspiration and use actual experimental data to verify it. Thefinal results show that the simulation results are similar with the experimental data. Thus theresult shows that the model can reflect the layered soil water movement rules on the summermaize growth condition.4、Using the mathematical model of one-dimensional layered soil water, this paper makesa preliminary forecast and analysis on soil water movement on the condition of climatechanging and evapotranspiration increasing. The results show that with the evapotranspirationincreasing, the soil water content gradually decrease, and may increase the risk of agriculturaldrought occurred.