Study On Irrigation Channel Optimize Model And The Unsteady Flow Transition Process Similation

water is the source of life and the lifeblood of the development of national economy. The increasingly sharp contradiction between supply and demand of water resources is the main factor which restricts the development of the national economy. Agricultural water whose a large part is irrigation accounts for 70% of the total water consumption. To cope with the water shortages,we must take some measures to save irrigation water. Irrigation is to allot flow in space and time on the condition of the water meet the crop requirement. The process of irrigation includes the plan of flow distribution and the action of the plan,etc.The main research purpose of this essay is to achieve the efficient use of water resources,improve the utilization rate of water and reduce loss amount of water by optimizing the water distribution model and the implementation of the plan. This research includes two aspects:canal water optimized model and unsteady flow transient simulation.The optimization water distribution model is to build multi-objective mathematical model which including minimizing the difference of the time and flow between the rotation irrigation groups and rotational irrigation.The improved genetic algorithm and elite reserve strategy are used to solve this model and the irrigation data of Feng Gushan reservoir irrigation area is used to validate the model.The main results are as follows:In the water distribution model, the realization of the canal water distribution plan in the irrigation area is taken into account. Flow and time, 2 key factors, are regarded as the 2 goals of the model. This model could solve the following 2 serious problems: the difference of water flow in the process of water conveying and water loss; From the optimization result, scientific and reasonable water distribution scheme can decrease the times of the gate adjustment, reduce the channel water disturbance, improve the effect of water distribution.So these factors should be taken into consideration in the water distribution process.The unsteady flow simulation study is mainly to simulate the canal system controlled by gate,water flow and level transient process.The simulation system was established on the unsteady creep flow control equations,taking channel length,flow rate, gate control time, gate control method as variable factor,simulating different working conditions the transition process of water level and flow rate.The main results are as follows:The channel length, flow rate, the gate control time are the sensitive parameters that affect the water level and discharge.Gate regulation mode is not the sensitivity.The influence of different control methods on water level is contrary and on water flow is similar.The downstream operation mode of the final water level stable value is lower than the upstream,which causes the channel design water level is lower and reduces work quantity,saving money;The longer the channel,the smaller the flow rat and the shorter the gate regulation time,the shorter time needed for the flow transition,the smaller the maximum water level,the the slower the flow fluctuation process and the safer the running channel.