|
Most parts of China agriculture is dependent on irrigation, agricultural irrigation water use, however, China's water shortage situation is grim and urgent need to improve agricultural irrigation management, water conservation and other aspects. In this context, understand the different regions, different stages of development of agricultural water demand situation is critical to the analysis of water-saving potential and development of water resources rational allocation program. In this thesis Survey, existing production and analysis of research results, a study focused on the national agricultural irrigation water demand. In this study, three partitions to the National Water Resources as the basic unit, to binding agricultural zoning and meteorological partition collect large amounts of data such as meteorological, crop, irrigation test, the irrigation requirement database. In this thesis, the calculation of agricultural irrigation water demand under fully irrigated conditions. Crop water demand computing crop, crop by crop coefficient multiplied by the reference crop evapotranspiration get. Reference crop evapotranspiration using Penman-Monteith method recommended by the UN Food and Agriculture (FAO). The crop coefficient is calculated single-value crop coefficient approach recommended by the FAO. According to the information collected, calculated net irrigation water demand for the nation's major crops. Typical crops and typical area in the country selected, the calculated results with irrigation test data comparison, reasonable and calculated results were analyzed. Affected by the climatic conditions, the multi-year average of the annual reference crop evapotranspiration in China's southern coastal areas and northwest arid regions, while the the northeast north and the Sichuan Basin, a small area near. Geographically, the major crops, crop coefficient doesnot Southern fertility initial value, the growth medium and mature northern characteristics. Reference crop evapotranspiration sensitivity analysis are warm season maximum temperature (Tmax) sensitivity greatest impact; cold season in the northern average wind speed (U) sensitivity of the greatest impact, while the southern maximum temperature sensitivity of the maximum. Comparative analysis of different frequency hydrological year selected net irrigation requirement, irrigation water requirement of major crops at different frequencies calculated hydrological year can provide reference for agricultural irrigation planning and management. The use of GIS (geographic information system), Delphi and other software, the development of agricultural irrigation water management information system, agricultural irrigation water demand management functions, including data storage, query, calculation, display. In addition, according to the results of calculations compiled VBA query system can easily reference crop water requirements of the National Water three partitions major crops, crop water requirement, irrigation water demand queries.
|