Abstract: Based on PenmanMonteith model and partial derivatives, this paper analyzed the meteorological and crop data during 1961-2013, to assess the spatial dynamic variation of water deficit of spring wheat at different growth stages in the plateau agricultural region of eastern Qinghai Province. Meanwhile, sensitivity coefficients of the mean temperature, relative humidity, wind speed, and sunshine duration were studied. The result identified an increasing trend of water deficit of spring wheat at each growth stage since 1988. Moreover, the drought degree of spring wheat showed more aggravation during the period between sowing and jointing stages along the line of GuideJianzhaXunhua; the drought degree of spring wheat showed an increasing trend in the period between jointing and heading stages in the regions of “TongrenHualongMinhe”, where the change range was the largest. However, a decreasing trend of water deficit was found in most parts of the whole region studied during the period between heading and maturing stages. The profit/loss amount of precipitation in the whole growth stage was the most sensitive variable to sunshine duration. The positively sensitive area to average air temperature was distributed in the valley of Huangshui River, while that to relative humidity, wind speed and sunshine duration was distributed in the northwestern part of eastern Qinghai. The findings from this study provide theoretical guidance on water resources management and regional irrigation scheduling.

Key words: vertical variation, loess hilly region, soil moisture, soil water storage characteristics, grey relational analysis., land use