秦巴山区国土空间格局演变特征及驱动力分析

[目的] 科学认知秦巴山区城镇空间、农业空间和生态空间的时空演化过程与形成机理,是助力全国空间发展格局统筹协调和推动中西部崛起的关键,更是地区高质量转型发展的迫切需求。[方法] 基于空间转移矩阵、地形位分析和随机森林回归等方法,从"格局规模―地形位置"2个维度切入,研究2000—2020年间秦巴山区国土空间时空演化特征与驱动机制。[结果] (1)近20年秦巴山区城镇剧烈扩张、农业和生态空间持续缩减,占比58.33%的县区人口减少的同时城镇用地依然呈扩张态势,"人口总量―城镇规模"出现严重两极分化;(2)城镇、农业空间"上山爬坡"、生态空间"下谷"现象明显,新增城镇和农业空间平均上移1~2个地形位,下游丹江口水库坝体加高工程对山区整体国土空间分布梯度产生显著影响;(3)"农业空间―生态空间"动态调整置换是秦巴山区主导转换类型,财政支出的影响作用最为显著;农业空间是新增城镇的主要来源,同时秦巴山区城镇退化为农业、生态空间的规模显著;(4)国土开发政策、山地地形属性、交通区位条件和社会经济因素共同制约影响秦巴山区国土空间演化结果,各类型因素在不同转换方向上的作用强度和显著因子数量有明显差异。[结论] 推动新增城镇向重点开发区集中,科学引导农业和生态空间顺应地形梯度布局,慎重进行水利工程建设,整体谋划区域"三区三线"布局,将对秦巴山区国土空间格局优化起到积极影响。

Analysis on the Evolution Characteristics and Driving Forces of Territorial Space Pattern in the Qinling-Daba Mountain Area

[Objective] To scientifically understand the spatio-temporal evolution process and formation mechanism of urban space, agricultural space and ecological space in Qinling-Daba Mountain area is the key to promote the overall coordination of the national spatial development pattern and the rise of the central and western regions, and it is also an urgent need for high-quality transformation and development of the region. [Methods] Based on the methods of spatial transfer matrix, topographic location analysis and random forest regression, the spatial and temporal evolution characteristics and driving mechanism of Qinba Mountain region during 2000—2020 were studied from two dimensions of "pattern scale-topographic location". [Results] (1) In the past 20 years, the cities and towns in the Qinba Mountain area expanded dramatically, and the agricultural and ecological space continued to shrink. While the population of 58.33% of the counties decreased, the urban land was still expanding, and the "total population and urban size" showed a serious polarization. (2) The phenomenon was characterized by urban and agricultural space "climbing up the hills", while ecological space "descended into the valleys". The newly added urban and agricultural space was moved up 1 to 2 topographic positions on average. The dam elevation project of Danjiangkou Reservoir downstream had a significant impact on the overall spatial distribution gradient of the mountainous areas. (3) The dynamic adjustment and replacement of "agricultural space to ecological space" was the leading type of transformation in Qinba Mountain area, and the influence of fiscal expenditure was the most significant. Agricultural space was the main source of new towns, and the scale of urban degradation into agricultural and ecological space was significant in Qinba mountain area. (4) Land development policies, mountain terrain attributes, traffic location conditions and social and economic factors jointly restrict and affect the results of territorial spatial evolution in Qinba Mountain area, and there were obvious differences in the effect intensity and the number of significant factors of various types of factors in different conversion directions. [Conclusion] Promoting the concentration of new towns to the key development zones, scientifically guiding agricultural and ecological space to conform to the topographic gradient layout, carefully carrying out water conservancy project construction, and planning the overall regional layout of the "Three districs and Three lines" will have a positive impact on the optimization of territorial spatial pattern in Qinba Mountain area.