黄土丘陵区旱地春小麦气候适宜度及其变化特征——以定西市李家堡乡麻子川村为例

为应对气候变暖对农业生产的影响，定量评价气候要素对春小麦生长的影响，运用模糊数学理论和滑动平均模拟法，利用前人建立的气候适宜度模型，进行春小麦气温、降水、日照隶属度模型和气候适宜度模型的研究。结果表明：春小麦全生育期气温、降水适宜度呈下降趋势，而日照无明显变化趋势。生育期内日照适宜度最高，气温次之，降水适宜度最低。苗期降水适宜度最低,抽穗期次之，气温适宜度苗期最低，变异系数最大，表明苗期的降水和气温是影响春小麦生长的关键，其次是抽穗期。降水是制约旱地春小麦生长最关键的气候因素，且气候适宜度随气候变化呈下降趋势，并在各发育阶段和年际变化过程中都呈不稳定波动状态，对春小麦生长具有极显著的负效应。全球气候变化增加了黄土丘陵区春小麦生产的气候风险。

Climate Suitability Degree and Its Change for Spring Wheat in Dryland in the Hilly-gully Region of the Loess Plateau —A 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.