Abstract: Drought and flood are the important factors that affect the development of agricultural economy in Xinyang. Analysis of water supply-demand and drought characteristics of winter wheat nearly 50 years can provide a theoretical reference for the rational layout of yielding, reasonable water use and policy formulation for disaster prevention and mitigation of winter wheat. Based on the daily scale data of 9 meteorological stations in Xinyang area from 1962 to 2011 year, the effective precipitation and water demand in the whole growth period and the growth stage of winter wheat were estimated. The temporal and spatial characteristics of water supply and demand were analyzed in the calculation of water budget index and the analysis of drought characteristics were studied by using SPI at different time scales. The results showed that the value of the spatial distribution of water demand in winter wheat in the northwest and southeast were higher and the central region was relatively lower. In terms of trends, the change trend of time was increasing. The growth period of winter wheat water budget index showed that water deficit, and compared to the central and southern region, water deficit was more serious in the northwest. In terms of trends, the change trend of time is decreasing. The SPI value of winter wheat was not significantly decreased during the whole growth period, and the variation range was 0.125·10a^-1. There was no significant decreasing trend in the SPI value of winter wheat during the pre-winter growth period, reviving and heading period and grain-filling and ripening period, while the SPI value in the wintering period showed no significant increasing trend. There were differences in the occurrence of drought at different growth stages, and the occurrence frequency of mild drought and frequency of drought in different growth stages were also different. The mild and or more serious drought frequency in the northern region was higher than that in the northern and southern region, and the drought frequency with moderate or higher severities was higher in the western and southern region. In conclusion, the water of winter wheat in Xinyang was deficient, and the drought status of each growth stage was different.

Key words: drought, winter wheat, water supply and demand, standardized precipitation index, Xinyang