京津冀地区农产品集聚及时空演变特征

［目的］基于1980—2015分5年1期的京津冀地区各县市播种总面积，以及14类农产品播种面积、产量等数据。研究京津冀地区各农产品的集聚程度、集聚结构稳定性以及集聚的空间分布与转移，为政府因地制宜地制定农业政策，农产品加工企业的选址提供数据支持与参考。［方法］综合运用区位商、基尼系数、产业集中率以及重心分析法，分析京津冀地区农业生产的地理集聚和时空演变特征。［结果］（1）稻谷、大豆、薯类、棉花、果园、水产和禽蛋的集聚度在不断地增强； 小麦、玉米、油料、肉类和林业的集聚度保持相对稳定； 蔬菜和牛奶的集聚度在不断地降低。（2）SQ与Q>1两者总体呈反向变化，即Q>1的值减小，农作物SQ值增加，集聚程度增强；Q>1的值增加，农作物SQ值减小，集聚程度降低。（3）不同行业农产品的集聚度高低为：水产业>林业>畜牧业>经济作物（含蔬菜和果园）>粮食作物，且经济作物和粮食作物的集聚度在不断的增强。（4）各农产品的生产结构稳定性大小排列：玉米>水产>小麦>蔬菜>果园>稻谷>牛奶>大豆>肉类>薯类>油料>林产品>棉花>禽蛋。［结论］京津冀地区农产品集聚度总体在提高，少数农产品的集聚度在降低； 各农产品生产重心总体朝着京津冀外围转移。

CHARACTERISTICS OF AGRICULTURAL PRODUCT AGGLOMERATION AND SPATIAL TEMPORAL EVOLUTION IN BEIJING TIANJIN HEBEI REGION

Based on the data of the total area planted in all the counties and cities of Beijing Tianjin Hebei region, as well as the planting area and output of 14 agricultural products from 1980 to 2015 (five year divided into one phase),this study provides data support and reference for the government to formulate agricultural policies and the location of agricultural product processing enterprises by studying the concentration of various agricultural products in the Beijing Tianjin Hebei region, the stability of agglomeration structure, and the spatial distribution and transfer of agglomeration. The location agglomeration, Gini coefficient, industrial concentration rate and center of gravity analysis were used to analyze the geographical agglomeration and spatio temporal evolution characteristics of agricultural production in Beijing Tianjin Hebei region. The major results show as follows.(1) The concentration of rice, soybean, potato, cotton, orchard, aquatic products and poultry eggs continue to increase; the concentration of wheat, corn, oil, meat and forestry remain relatively stable; the concentration of vegetables and milk is constantly decreasing. (2) The value of Q>1 decreases, the SQ value of crops increases, then the degree of agglomeration increases. The value of Q>1 increases, the SQ value of crops decreases, then the degree of agglomeration decreases. The two values generally change in the opposite direction. (3) The order of concentration of agricultural products in different industries is: aquaculture>forestry>livestock>economic crops (including vegetables and orchards)>food crops, and the concentration of economic crops and food crops is continuously increasing. (4) The stability of production structure of each agricultural product is arranged as follows: corn > aquatic > wheat > vegetable > orchard > rice > milk > soybean > meat > potato > oil > forest product > cotton > poultry egg. The concentration of agricultural products in the Beijing Tianjin Hebei region is generally improved, and the concentration of a few agricultural products is decreasing. The overall production focus of agricultural products is shifted to the periphery of Beijing Tianjin Hebei region.