| Water shortage is a common issue in the global development, which faced with lots of public concerns. Solving water shortage in the irrigation area is important because China is a great agricultural country. Therefore, research and application on the economical water-use effectively addresses the issue with significantly theoretical value and practical meaning. In this dissertation, a great deal of information is collected on the basis of field survey under the guidance of the related theories and technical guidance with multi-disciplines relating to water conservancy, geography, economy, mathematics, management, and computer. It takes the typical and representative Baojixia Irrigation Area in Shaanxi Province as the research object. And with "Scientific Outlook on Development" and "Development Based on Water Conservancy" as the research idea, in using the related methods such as questionnaire survey, depth interviews mathematical statistics, comparative analysis, mathematical modeling, GIS space simulation, object-oriented software development and so on the calculation of the balance on supply and demand was given. The predictive analytics via GM model was given too. We also try to put forward the concept of economical water-use mode for irrigation area and make some analysis on the ground in relation to total amount control of water resources, inadequate irrigation schedule, water rights and water markets, etc.. Then the Baojixia Irrigation Area was partitioned, and the multi-criteria decision making mathematical model for economic water utilization was set up. Finally, we integrate theory with practice on the software applications such as WebGIS,Visual Basic,SQL Server 200,etc. In order to design and develop the B/S and C/S integrated and network-based decision support system for economic water utilization in the Irrigation Area. I made some conclusions based on the research:1) With regard to total amount control of water resources, economical water-use model of arid and semi-arid refers to a kind of new water-use management mode was made. It enables to maximize the combined revenues or social benefit through scientific and rational water resource distribution in the irrigation area via inadequate irrigation schedule, with full considerations on engineering water conservation, field water conservation, efficient and optimizing water transfer. It will be applied to Baojixia Irrigation Area with distinct advantage; 2) It also refers to water distribution model according to water rights governed by farmers' water user association; 3) Adequate irrigation schedule in wet year for the irrigation area is available for 25% economic water-use amount by maximizing economic benefit for the objective function. The maximal economic benefits are assured in the irrigation area despite of minimal surplus water amount to promote its economic development and use surplus water amount to compensate the social and ecological benefit; 4) Inadequate irrigation schedule in mean water year will prevail for 50% economic water-use amount to maximize economic benefit with equal economic, social and ecological benefit as result of elimination of water shortage and slight surplus; 5) Inadequate irrigation schedule in low water year (75%) was commanded in economic water-use. And it can maximize economic benefit with equal economic, social and ecological benefit for minimal water shortage amount, as well as ease the imbalance between supply and demand; 6) Decision support system for economic water utilization in the Baojixia Irrigation Area is used for several purposes, featured as powerful friendly interface, easy and efficient operation, and reliable performance. It is used for the management and decision-making to enhance the management of irrigation area and informationization. The essay works on the promotion from engineering water conservancy to water resources conservancy to get track on resource-conserving environmental friendly and harmonious development as soon as possible, and protect sustainable economic and social development for the irrigation area through sustainable utilization of water resources. |
