Abstract: Irrigation is one of the effective measures to resist and alleviate the impact of late frost disaster on winter wheat. Aiming at the strong cold weather process occurred in HuangHuai Area of Central China in April 2010, and through a field experiment with irrigation to prevent frost in Zhengzhou agrometeorological observation station, this paper analyzed the characteristics of air and soil temperature in winter wheat field at booting stage. The results showed that when the environmental temperature dropped, irrigation could increase the minimum air temperature by 0.1-0.6 ℃, compared with no irrigation. The effect of irrigation in increasing air temperature was mainly concentrated in the 5 cm zone above soil surface. In addition, irrigation could shorten the duration of air temperate ≤ 0 ℃ by 1-2 h. The soil temperature under irrigation varied with soil depth, being higher at 0 cm depth but lower at 5-20 cm depth, as compared with no irrigation. Irrigation decreased the coefficient of variance and relative variability of air temperature and 0-5 cm soil temperature, but increased the two indices of 10-20 cm soil temperature. The differences of soil temperature caused by irrigation were distinct at 15  and 20 cm soil depths, but not obvious at other soil depths.

Key words: natural reserve, camping site, environmental suitability, GIS technology, analytic hierarchy process (AHP).