| In order to search the method for quantitative assessment of drought disaster to the loss of winter wheat in arid region, taking the Juxian County in Shandong Province as the case study, using the thirty years’ meteorological records (1981—2010) of Juxian County and yearly growth period
of winter wheat and the observation data of soil moisture over the years, applied the FAO PM formula, have calculated the possible evapotranspiration, water requirements and soil water deficiency rate for the different growth stages of winter wheat based on the meteorological standards as “The Grade of Drought Disaster for Wheat”, also carried out the research of the correction and application for the crop coefficient (Kc) values in the middle and late stage of wheat and the relative calculation formula. The results showed that; The total potential evapotranspiration was 518.741 mm in whole growing period of wheat; The whole water requirements of wheat was 466.393 mm by the different crop coefficients and the whole water requirements of wheat was 440.93 mm by the average crop coefficient. Also calculated water deficiency was coincided to the reality with good effect. So the method that the water deficiency evaluate the loss of wheat in the arid region was available, and it can be met the requirement to forecast the wheat yield based on the water deficiency rates. It can be provided a practical reference for the basic level scientific researchers to master and understand this method. |