Water Movement And Salt Transfer Characteristics And Simulation Under Film Drip Irrigation

Film drip irrigation is one of the main paths to realize saline-alkaline soil resource. On the basis of using for reference of film drip irrigation and saline-alkaline soil amelioration both abroad and home, the paper adopted adjoin method of both indoor experiments and model simulations, soil water movement and salt transfer characteristics is studied under film drip irrigation, effects of comprehensive is analyzed by combining film drip irrigation technique and traditional saline-alkaline soil amelioration. It is established to provide new idea and method of scientific exploitation and amelioration for saline-alkaline soil. It made conclusions as below:(1) Effects of point source and intersection infiltration on soil water movement and salt transfer characteristics for saline-alkaline soil. In point source infiltration condition, the same drop water, the drip discharge is increased, the desalinization zone coefficient and the up-to-par desalinization zone coefficient are decreasing. Drop discharge is not favor formation of desalinization zone. The same drop discharge, the drop water is increased, the desalinization zone coefficient and the up-to-par desalinization zone coefficient are increasing. Drop water is favor formation of desalinization zone. In point source intersection infiltration condition, the same drop water, the drip discharge is increased, the desalinization zone coefficient and the up-to-par desalinization zone coefficient in vertical section and intersection side are decreasing. The same drop discharge, the drop water is increased, the desalinization zone coefficient and the up-to-par desalinization zone coefficient in vertical section and intersection side are increasing. In the same drip discharge and drop water, with the drippers spacing increasing, the desalinization zone coefficient and the up-to-par desalinization zone coefficient in vertical section and intersection side are decreasing. When the drippers spacing reducing, it is propitious to desalinize soil salt.(2) Effects of chemical amelioration on saline-alkaline soil water movement and salt transfer characteristics under film drip irrigation.Through drip irrigation with Ca(NO3)2, through comprehensive evaluation of the coefficient of up-to-par desalinization zone and coefficients for the depth of sodium desalinization zone and sodium absorption ratio, the desalinization effect of Ca-W-Ca is also superior to other modes. Through drip irrigation with Ca(NO3)2 and KN03, in the same concentration, coefficients for the depth of sodium desalinization zone use-calcium concentration is better than use-kalium concentration, the desalinization effect of use-calcium is also superior to use-kalium. The desalinization effect of use-calcium 2000mg/L is also better than other concentrations. In the same infiltration condition, the gypsum proportion is increased, coefficients for the depth of sodium desalinization zone is increasing, the desalinization effect is distinct, when the gypsum proportions is 0.1, coefficients for the depth of sodium desalinization zone increment is better than other gypsum proportions, it is propitious to wash soil surface layer salt. The desalinization effect of 0.1 is also superior to other gypsum proportions.(3) Effects of physical amelioration on saline-alkaline soil water movement and salt transfer characteristics under film drip irrigation. In the same infiltration condition, When the wheat straw hood length is 0.1cm, the soil water content of 0.1cm is also superior to other straw hood length, the salt properties coefficient of 0.1cm is better than other wheat straw hood length. The desalinization effect of 0.1cm is also superior to others. In the same infiltration condition, the desalinization effect of 0.1 is also superior to other wheat straw hood proportions. In the same infiltration condition, the sand proportion is 0.1, the rate of salt properties coefficient increment is better than other sand proportions. When the same proportion is 0.1, the desalinization effect of sand is also superior to wheat straw hood.(4) Study on simulation of saline-alkaline soil under drip irrigation. In point source and intersection infiltration condition, the simulation of Saline-alkaline soil is researched. The point source and intersection model for drip irrigation is build. Soil water content and the horizontal and vertical movement wetted front are simulated by Matlab. The result of simulation is identical changed between simulation and actual measurement.(5) Study on parameter identification and optimization of soil water movement under drip irrigation. According to existing problem of water movement to model using differential equation and mathematical statistics method on unable accurately obtaining boundary conditions and analytical solution under drip irrigation, in same drip irrigation condition, the advantage of AIGA and PSO is compare by identification and optimization characteristic parameter of soil transfer. The transfer function models between drip discharge and water movement distance are established. The particle swarm optimization algorithm has been applied to identification and optimization of every parameter of the transfer function model. Comparing the dynamic transformation of soil water movement models of same drip discharge, the validity of transfer function model is validated, adjusting real time drip discharge is proposed by transfer function model.