Study On Saline Water Irrigation Options In Hetao Irrigation District In Inner Mongolia

Combining the project 'the study of water balance mechanism and water demand' supported by National Natural Science Foundation of China (NSFC), this thesis study the suitable saline water irrigation schedule for this district by the simulation of groundwater flow and solute transport with the software Visual MODFLOW based on the experiments in Hongwei Water-saving Area (HWSA) in Inner Mongolia Hetao Irrigation District. The main contents of this thesis are as following.Firstly, on the basis of reviewing a number of literatures both domestic and abroad, the advancement on the saline water irrigation were summarized systematically in this thesis. For there are lots of results concerned the saline water experiments, the theoretical analysis and scenario simulation of saline water irrigation, which mainly focus on the effect of saline water irrigation on the crop yield and the salt balance in the root zone while there is little results about the water and salt balance in the groundwater, so this thesis mainly focus on the simulation of water and salt balance in the groundwater by the means of the groundwater flow and solute transport simulation software Visual MODFLOW. The different scenarios were simulated and the best one were decided base on the salt balance in both unsaturated and saturated water, and the crop yield.Secondly, on the basis of water level and water quality experiment in HWSA in 2000 — 2002, the hydro geological parameters in the model were calibrated and validation with the data, and the model Modflow were tested satisfactorily.Thirdly, 18 saline water irrigation scenarios based on the different irrigation ration, the different irrigation times and the different irrigation types were simulated and the results were analyzed by the VMODFLOW with calibrated parameters. Combining the results of Wang Weiguang (2003), the optimal irrigation alternative was selected.It should be emphasized that only a great deal of water at the end of crop growth season can leach the salt accumulated in the soil, which is very important for the saline water irrigation.