| Based on the daily air temperature data of six counties of Zhangye in the central Hexi Corridor from 1961—2009, analysis was made of the spatial distributions, annual and decadal variations and climatic anomalous change year of the critical temperature≥10℃, as well as the effect of its evolvement on crop planting pattern, growth situation and maize output. The results are as follows: During the last 50 years, the variation trend of the critical temperature ≥10℃ presents the characteristics of the initial day becoming earlier, terminalday postponing, duration prolonging and the accumulated temperature increasing. In the 1970s—1980s, the phenomena of the accumulated temperature ≥10℃ decreasing and duration shortening occurred in most of the weather stations in the central Hexi Corridor; in the 1990s, the accumulated temperature increased obviously, and the increase extent in the years of 2001—2009 is the highest the last 50 years; and the phase of thermal abundance appeared. In the beginning of 1970s—1990s, the anomaly phenomena of the accumulated temperature≥10℃ decreasing and duration shortening occurred in most of the weather stations. During the period of 2000—2009, the anomalous increase years of critical temperature ≥10℃ accounted for 83% of the total in the last 50 years. The anomalous increase years, accumulated temperature ≥10℃ and thermal resources increased remarkably in maize growing period, which was helpful for enlarging planting area of the dominant crop maize, raised the yield of maize per unit area and the general output. |