Study On RS-GIS-Based Water Demand Forecast System In Irrigation Area

China is a country which is relative shortage of water resources. In the country, 80% of the total water consumed in agriculture, where irrigation water is the main agricultural use. According to our country, agricultural water has saving potential. Vigorously promoting the irrigation water demand forecasting technology, for water conservation, drought mitigation and guide our agriculture timely adequate irrigation has an important role.Traditional water management is based on pre-established system of rationing of irrigation water. Although the irrigation system is based on different hydrological years, water distribution programs, but it still can not adapt to changing weather conditions. With the development of technology, remote sensing and Geographic Information System provide a very effective problem-solving approach.With the help of scientific systems engineering and software engineering principles and methods, this articles try to use the RS raster data, GIS, database technology, mapping and other technical means of network technology combine to carry out research and development to create an integrated technological system, building a technical forecasting system of irrigation water demand for irrigation managers and users for help and reference.The design of the system functions as follows, by reading the RS raster data which provides irrigation soil moisture, to calculate the corresponding water demand, and the results written to the database, then the results will be announced through the network. The system can be divided into three sub-systems: Irrigation water demand computing systems, database systems and information distribution system.Irrigation water demand computing system mainly uses the raster finite element method, by reading the RS raster data which provide soil moisture and land-use type to calculate the current land use of different types of irrigation water needs and water requirements of various users.Database in the current system is mainly to store the basic information, including spatial data and attribute data, as well as irrigation water demand computing the results, to meet other requirements related to user queries.Information distribution system is mainly through WebGIS and networks to achieve the basic information on the inquiry irrigation operations, including spatial data and attribute data. In addition, users can also search by the relevant irrigation water requirement calculated by irrigation water demand computing system.