重庆市江津区土地资源承载力时空差异研究

针对重庆市江津区脆弱的生态环境本底和土地利用特点,从承载强度、承载效益、承载潜力3方面构建评价指标体系,对江津区2007～2016年土地资源承载力进行综合评价,并引入障碍度模型得出各乡镇土地资源承载力障碍因素。结果表明:(1)2007～2016年期间,江津区的土地资源承载力整体呈现出上升趋势,但上升幅度较小,土地资源承载力仍然偏低,各乡镇土地资源承载状态均未达到良好状态,仍需采取各种措施不断提升土地资源承载力,土地资源承载力的区域差距近年有所减小,空间上呈现出南高北低的空间格局;(2)各子系统对承载力的贡献大小不一,承载强度贡献最大,承载潜力次之,承载效益贡献最小,承载效益是提高土地资源承载力的关键;(3)江津区土地资源承载力的主要障碍因素是单位建设用地产出、林地占比、人均生态用地、环保投资指数、人均耕地面积、水域占比、水土流失率、未利用地占比、单位农用地产出,各乡镇障碍因素差别较大;(4)障碍因素不同的区域,应采取不同的措施提升土地资源承载力。主要城区和工业园区所在地应适当控制人口数量,严格限制农用地转为建设用地;生态环境脆弱地区应大力实施耕地休耕和退耕还林政策,促进农民生计方式转变;经济发展受生态保护限制的地区应转变经济发展方式和土地利用方式。

Temporal and Spatial Difference of Land Resource Carrying Capacity of Jangjin District in Chongqing

In view of the fragile ecological environment and land use characteristics of Jiangjin district in Chongqing, the evaluation index system is established from three aspects: carrying strength, carrying efficiency and carrying potential. The comprehensive evaluation method is used to evaluate the land resource carrying capacity of Jiangjin from 2007 to 2016, and the obstruction model is used to analyse obstacle factors of land resource carrying capacity in each township. The results show that: (1) During 2007 to 2016, the land resource carrying capacity of Jiangjin shows an overall upward trend, but the increase rate is small. The carrying capacity is still low, and none of townships has got a good state. Various measures are needed to continuously improve the land resource carrying capacity. The regional gap of the carrying capacity has decreased in recent years, which presents a spatial pattern of higher in the south and lower in the north. (2) The contribution of each subsystem varies. Carrying strength contributes the most, and then carrying potential. Carrying efficiency contributes the least, so carrying efficiency is the key to improve carrying capacity. (3) The main obstacle factors of land resource carrying capacity in Jiangjin are fixed asset investment density, unit construction land output, forest land proportion, per capita ecological land area, environment protection investment index, and per capita arable land area. The obstacle factors of each township are quite different. (4) Different measures should be taken in areas with different obstacle factors. The major urban areas and industrial parks should appropriately control population and strictly limit the conversion of agricultural land into construction land. The fragile ecological areas should vigorously implement the policies of arable land fallow and conversion of cropland to forest to promote the transformation of farmers’ livelihoods. Areas where economic development are restricted by ecological protection should transform the economic development mode and land use patterns.