Research Of The Theory For Optimal Water Distribution And The Management Decision-Making System In Irrigation District

Optimal water distribution in irrigation district(ID) is an important method and countermeasure for reasonably restraining the wate requirements, effectively increasing the water supply, and actively protecting the ecological environment etc. Therefore, improvement of the optimizing water distributing method have significances to distribute water for each user and realize the maximal benefits of the economy, society and ecological environment with the limited water resources and in harmony with the water quality and the water quantity. Discussing application of the genetic algorithms, Free search algorithms, and BP algorithms to the water distributiom in IDs are profitable for the water distributing theories.This research comes from the Ministry of Science and Technology's Program"863"of"The platform construction of the digital canal system and the application of the decision-making for precise water use"(2003AA209040)and the scientific research of the Northwest A & F University of"The research and development of the common model base for distributing water in ID"(04ZM070), using the Fengjiashan ID as for the research object,carried out the research for the theory of optimal water distribution and decision-making system. Aim at improving the effect of water distributing, the paper research the water distributing intelligence method ,theory, optimal model and the evaluation of using water management in ID, the application of genetic algorithms and free search algorithms. The contents and conclusion of this paper include:(1) According as the genetic theory, it is essential to discarding the traditional binary system coding for solving water distribution. Being consistent with the way of thinking of the problem, decimal system is adopted. Using seriation of the canal for coding, it is enhancing the efficiency for coding and reducing the difficulty of programmer. As the traditional gene coding can't reflecting the technique parameter of canal, the complex genecoding is introduced. The genome include several codes such as the number of canal, the discharge of canal, the level of canal etc. This method can give more scientific information for decision-making. It also make the result come close more to practice. (2) Considering GA sinking into the partial solution easily , free search algorithms is introduced. It extend the search space for algorithms, enhancing the quality of gene coding, adjusting the discharge of canal , making every canal close at the same time, decreasing the discarding water of canal, reducing the time of manual work. It have excellent theoretical and realistic effect on distributing water .(3) Only assigning the right amount water to every kind of farm crop at the right time can make the biggest profit for distributing water in ID. Putting the optimal purpose together with land and water resources will make water resources really getting optimal distribution. This article put forward a model to solve the question that how to select the irrigating quota on each application according to uncertain irrigation water use, uncertain climate and different optimal objectives. It has been put to use combining with the optimal cannal system model for distributing water.(4) Determining the index weight subjectively, confirming the data of index irrationality,evaluating the data illogicality is the limitation of comprehensive evaluation. Accordingly, MCA and Compromise Programming has been used on ID administrative levels. Determining the index weight by expert, adjusting the index weight by MCA, confirming the data space of the index value by statistics, and evaluating the irrigation district management by CP, it is it is more logical and reasonable for calculating the index weights and its data space, and evaluating the management in irrigation. The model is proved scientific and feasible in being applied to irrigation district. It have the beneficial quest on comprehensive evaluation theory.(5) under the market economy, whether the side of supplier or the user in water market, it is important for them to get profits. Pulling the economic lever well will have the important influence on water market. This text put forward a model to solve the question that how to evaluation of water cost for the whole interest according to inspiring motivation, giving the proper extension of the water price. It can provide scientific bases for the water pricing in ID.(6) Based on the research of water distributing method and models, developed computer management design-making system using modularization method. The system can realize the function of inquire, adjust the plan at any time according to actual circumstance and analysis the water information,evaluate the management in irrigation. practice expresses that the system is general ,practicable and expansible.