中国耕地非农化压力时空格局的演变分析

社会经济和资源禀赋的区域差异导致耕地非农化压力表现出明显的空间异质性。开展耕地非农化压力测算并揭示其时空格局演变,是实现土地资源优化配置的基础。从经济因素、社会因素、产业结构和资源禀赋4个方面构建耕地非农化压力指数评价指标体系,采用熵值法计算各指标权重,继而计算1990~2014年中国31省的耕地非农化压力指数,并在此基础上开展了耕地非农化压力的时空格局分析。结果表明:(1)从空间格局分布来看,中国耕地非农化压力空间分布呈现明显的地理梯度,总体上呈现从东到西依次递减的态势。(2)从时间变化趋势来看,不同地区各省份之间的耕地非农化压力指数变化呈现多元化趋势。东部沿海地区,山东、浙江、江苏的耕地非农化压力指数处于上升阶段,上海、福建的压力指数变化趋势逐渐趋稳,广东的压力指数呈现下降趋势。中部地区,河南、河北、山西、江西的耕地非农化压力指数趋稳,陕西、湖北以及四川、重庆等西南地区省份的压力指数呈上升趋势。西部沿边3省(云南、西藏、新疆)的耕地非农化压力呈现了一致的下降趋势。(3)从时空格局结合来看,耕地非农化压力不同的省份其变化趋势呈现出截然不同的走向。在耕地非农化压力较大的地区,耕地非农化经历了从制度驱动向发展推动的阶段,经济增长的倒"U"型轨迹明显,经济增长与耕地非农化之间的关系逐渐脱钩。在耕地非农化压力居中或较小的地区,产业发展滞后,土地比较收益较低,耕地的社会保障作用、生态作用对耕地非农化的影响较大,从而增加了部分省份的耕地非农化压力。

SPATIO-TEMPORAL PATTERN OF CHINESE FARMLAND CONVERSION PRESSURE

The regional differences in socioeconomic and resource endowments lead to significant spatial heterogeneity of farmland conversion.It is the basis for optimizing the allocation of land resources to carry out non-agricultural pressure measurement and reveal its spatio-temporal evolution pattern.In this paper,the evaluation index system of farmland non-agricultural pressure is constructed from four aspects of economic factors,social factors,industrial structure and resource endowment.The entropy method is used to calculate the weight of each index,and then calculate the farmland non-agricultural pressure in China from 1990 to 2014.Then based on this,the spatio-temporal pattern of farmland non-agricultural pressure is analyzed.The results show:(1) From the point of view of the spatial,the spatial distribution of farmland non-agricultural pressure shows a clear gradient,which shows a decreasing trend from east to west in general.(2)From the trend of time,the change of farmland non-agricultural pressure in different provinces show diversified trend.In eastern China,the pressure of farmland in Shandong,Zhejiang and Jiangsu were on the rise,while the pressure of Shanghai and Fujian gradually became stable.The pressure index of Guangdong showed a downward trend.The non-agricultural pressure index in the central regions,Henan,Hebei,Shanxi and Jiangxi stabilized,and Shaanxi,Hubei,Sichuan and Chongqing were on the rise.The non-agricultural pressure of cultivated land in the three western provinces (Yunnan,Tibet and Xinjiang) showed a consistent downward trend.(3)From the combination of spatio-temporal patterns,the changing trend of farmland non-agricultural pressure shows a different trend.In the areas with larger non-agricultural pressure,the non-agriculturalization of farmland experienced a stage from the system-driven to the development-impetus.The U-shaped trajectory of economic growth was obvious.The relationship between economic growth and farmland non-agriculturalization was gradually decoupled.Conversely the areas with less pressure,the development of the industry is lagging behind,and land comparative income is low.Then the social security function and the ecological effect of farmland have great impact on the nonagriculturalization of farmland,thus affecting the non-agricultural change of farmland in some provinces.