基于BRT模型的合肥中心城区蓝绿空间时空演变及驱动因素研究

Spatiotemporal Dynamics and Driving Factors of Urban Blue-Green Space in Central Hefei Based on BRT Model

蓝绿空间是城市用地重要组成部分,探究高速城市化进程下蓝绿空间的时空演变及驱动因素,有助于揭示其演化规律,为相关研究及政策制定提供基础。以合肥为例,基于面积变化强度、土地转移矩阵、多阶邻接指数研究中心城区蓝绿空间的时空变化;采用增强回归树模型探讨影响城市蓝绿空间扩张的驱动因子。结果表明:(1)2000-2020年,合肥中心城区蓝绿空间总体规模增长了14.8%,呈现稳步增加的阶段性特征。(2)研究时段内合肥中心城区蓝绿空间扩张模式均以边缘式为主、邻接式为辅;新增蓝绿斑块沿大型自然蓝绿斑块集聚,蓝绿空间扩张由城市边缘转向内部。(3)自然要素因子对蓝绿空间扩张的影响(80.8%)大于社会经济因子(19.2%),其中高程(32.1%)、坡度(26.9%)、坡向(21.8%)、人口密度(13%)、第三产业增加值(6.2%)是主要驱动因子。研究探明了近20年来合肥中心城区蓝绿空间的时空演变特征及驱动因子,可为未来城市蓝绿空间规划管理及可持续发展提供支撑。

The blue-green space in Chinese cities is important for urban land use.Exploring the spatiotemporal dynamics and driving factors of blue-green spaces under rapid urbanization processes contributes to unveiling the evolutionary patterns of urban blue-green spaces,which provides a fundamental basis for related research and policy formulation.In this study,remote sensing imagery was used to calculate the extent of blue-green spaces from 2000 to 2020,and we analyzed the evolution using the in-tensity of area change,a land transfer matrix,the multi-order adjacency index,and a boosted regression tree model.This study revealed the spatiotemporal dynamics and driving factors of blue-green spaces in the central area of Hefei from 2000 to 2020,particularly:(1)Between 2000 and 2020,there was a 14.8%net increase in the total area of blue-green spaces in Hefei’s central area.(2)Blue-green spaces primarily showed fringe-type expansion and proximity-type expansion.Spatially,new blue-green patches tended to cluster around large pre-existing natural blue-green patches.Furthermore,the expansion of blue-green spaces shifted from the urban periphery to the urban interior.(3)Natural factors exerted a greater infl uence(80.8%)on the expansion of blue-green spaces than did socioeconomic factors(19.2%).DEM(32.1%),slope(26.9%),aspect(21.8%),population density(PD)(13%),and value-added by the tertiary industry(VATI)(6.2%)were identifi ed as the primary driving factors.The results contribute to understanding changes in urban blue-green spaces and the driving factors behind these changes,thereby providing support for future planning,protection,and sustainable development of urban blue-green spaces.