Climate Suitability Degree and Its Change for Spring Wheat in Dryland in the Hilly-gully Region of the Loess PlateauA Case Study in Mazichuan Village,Lijiabao Township,Dingxi City
In this paper,the climate suitability degree at different growth stages of spring wheat was studied so as to reveal the influence of global warming on agricultural production and assess quantitatively the effects of meteorological factors on the growth of spring wheat. The membership model and the climate suitability degree model were used to research the suitability degree of temperature,precipitation and sunshine at different growth stages of spring wheat in dryland during the period of 1970 - 2010 based on the fuzzy mathematical theory and the moving average simulation. The results showed that the suitability degree of temperature and precipitation at growing stage of spring wheat decreased,but the variation of suitability degree of sunshine was not significant. In growth period of spring wheat,the suitability degree of sunshine was the highest,then that of temperature,and that of precipitation was the lowest,so inadequate precipitation was the main meteorological factor restricting the growth of spring wheat in Gansu Province. The suitability degree of precipitation was the lowest at seedling stage of spring wheat,and then in heading period. The suitability degree of temperature was the lowest at seedling stage,the variation coefficient was the highest,and these revealed that precipitation and temperature were the key factors affecting the growth of spring wheat at seedling stage,and then in heading period. Precipitation was the most significant factor restricting the growth of spring wheat in dryland,and the climate suitability degree was in a decrease trend with climate change, which was negative for the growth of spring wheat. Global climate change has increased the climate risk of wheat production in the hilly-gully region of the Loess Plateau.