Agricultural Irrigation Water Requirement And Its Regional Characteristic In China

Agriculture mostly depend on irrigation in China, and irrigation use much water.Now water shortage becomes a serious problem in China, so agriculture irrigationneed improve method in water management and water save. It need us to find outagriculture water use in different area and different phase, and it is very important forwater save potential and water resources rational deployment. In this thesis,agricultural irrigation water requirement is mainly estimated through investigation orscientific research.Using water resources third class subareas as basic cell in whole country,combining with the agriculture and weather subareas, many data has been collected tobuild irrigation water data-base, such as for station, weather, crop, irrigation trial andso on. The irrigation water requirement is mainly focused on full irrigation . Cropwater requirement is calculated from the product of reference evapotranspiration andcrop coefficient. Reference evapotranspiration is evaluated by Penman-Monteithmethod newly recommend by FAO. Crop coefficient is evaluated by singlecoefficient approach recommended by FAO. Based on the data collected in this study,net irrigation water requirement of main crop in china has been gotten. Thecalculation results are compared with the data of local irrigation trial to validate itsrationality。Under the influence of the climate, the yearly average of referenceevapotranspiration has two maximum in China, one is in south littoral and the other isin northwest arid area. In the other hand, it is much smaller in northeast and inSichuan Basin. The yearly crop coefficient of main crop in China has characteristicfor that in south area the initial period crop coefficient is much bigger, and in northarea the mid-season or late-season crop coefficient is much bigger. From thesensitivity analysis of reference evapotranspiration mainly discover that in warmseason the maximal air temperature has the biggest sensitivity;in cold season theaverage wind speed has the biggest sensitivity in north and the maximal airtemperature has the biggest sensitivity in south of China. The thesis also makeanalysis on irrigation water requirement in different frequency of hydrological year .The results provided a scientific referrence for agricultural irrigation program ormanagement.Using GIS(Geographical Information system), Delphi soft etc., this studydeveloped Agriculture Irrigation Management Information System(AIMIS). It hasrealized to manage the agriculture irrigation for data keeping, checking, accounting,displaying and so on. In the other hand, according to the results of the study, VBAchecking system has been developed. It is convenient to check the main crop data inwhole country for third class subarea of water resources such as referenceevapotranspiration, crop water requirement and irrigation water requirement .