North Expansion Climate Zoning And Drought Risk Assessment Of Apple In Yanan

As the representative of important apple production region in Shaanxi loessial plateau area, Yan’an city has primary apple production yield in China. With the rapid development of fruit industry, apple industry is growing to be the pillar of local economy and one of important factor for increasing farmer’s income. Affected by global climate warming and the influence of governmental encourage policies of Shaanxi Province, apple planting area of Yan’an is gradually northward moving. The problems that government and people concerned are:the possibility to northward apple planting area, any difficulties will be faced if do northward expansion. By analyzing climate characteristic of nearly thirty years, this paper proposes the indexes for the climatic division and suitability of apple growth Yan’an area according to varietal eco-climate suitability and regional climate characteristics. By using GIS technology (Geographic Information Systems), to realizing spatialization of regional climate index; adopting methods of score by experts and fuzzy mathematics, the paper evaluates regional climate suitability. Per the evaluation, it concludes that most of north areas of Yan’an city are suitable or sub-suitable region for apple planting, and part unsuitable region.Meanwhile, the paper studies the impact of drought weather to apple planting and divides regionally on drought risks to Yan’an apple planting by adapting GIS technology and analyzing nearly thirty years climate data. It turns out that about sixty percent of Yan’an northern areas are high risk region and second high risk region.Through study of climate suitability and drought risk on apple planting in Yan’an area, it indicates the difficulty remaining in seven counties located in north of Yan’an city, especially Wuqi and Zhidan County. Thus, comparing the climate of two counties and continuing the study of possibility to plant apple in Wuqi and Zhidan County become a topic of this paper. Given above situation, this article takes Jingning County which well known as "The apple town of China" be a reference, with comparative analysis of climatic resources and meteorological indicators of apple planting, it results Wuqi and Zhidan county have better hydro-thermal condition than Jingning county, which provide climate basis for expanding apple planting northward. Drought in spring and early summer, freeze injury in florescence are two main factors that restrict the northward expansion of apple planting.To Sum up, in order to implement the policy of northward expanding apple plant area, the paper propose following strategy and suggestion:Frist:selecting good apple variety to gradually expand apple cultivated area. Meanwhile, integrating with "Return Farmland to Forests" program to plant apple on mountainous region;Second:increasing investment on artificial precipitation, spreading measures of rainwater catchment, improving water use efficiency, appropriate artificial irrigation, which will decrease drought impact to apple cultivation;Third:enhance the study of preventing freeze injury to apple florescence.