黄河流域城市群扩张的时空格局演化及情景模拟——以呼包鄂榆城市群为例

黄河流域城镇扩张对区域景观格局影响显著,城市群人口聚集与增长引发了流域“人-地”矛盾和“空间冲突”等一系列生态环境问题。基于土地利用数据和FLUS模型对2025年和2035年呼包鄂榆城市群城镇化与土地利用时空演化特征进行多情景模拟预测。结果表明：① 1990—2018年呼包鄂榆城市群整体发展水平较低,建设用地面积经历了“平稳增加-缓慢增加-急剧增加”的变化过程,区域总体以草地为主,其占土地总面积的50%以上,其次是未利用土地和耕地,林地和建设用地次之。② 城市群扩张最剧烈地区在空间上主要发生在呼和浩特市、包头市等城市主城区,且扩张模式以外延式扩张为主,扩张来源主要是耕地、草地等生态用地。③ 三种情景模拟发现,2025年和2035年区域土地利用变化的空间结构和特征差异明显。自然发展情景下,城市扩张不受约束,高速增长占据了大量生态用地;加入生态约束条件很好的控制了对草地和林地的占用;经济发展情景下,城市扩张将进一步占据更多的未利用土地和耕地。本研究通过城市群扩张时空格局演化及情景模拟分析,尝试为区域规划、城市空间规划和区域生态空间保护提供多角度、多情景和可选择的政策决策参考。

The evolution of spatio-temporal pattern and scenario simulation of urban agglomeration expansion in the Yellow River Basin: A case study in the Hohhot-Baotou-Ordos-Yulin Urban Agglomeration

The urban expansion in the Yellow River Basin has a significant impact on the regional landscape patterns. Moreover, the continuous gathering and growth of the population in urban agglomerations have caused “human-land” contradictions, “spatial conflicts”, and a series of ecological and environmental problems in the basin. Based on the land use data and FLUS (Future Land Use Simulation, FLUS) model, we conducted multi-scenario simulation of the urbanization and the spatio-temporal land use evolution characteristics of the Hohhot-Baotou-Ordos-Yulin Urban Agglomeration (HBOY Urban Agglomeration) in 2025 and 2035. The results show that: (1) The overall development level of the HBOY Urban Agglomeration is low from 1990 to 2018, and the area of construction lands experienced a process of “steady increase-slow increase-sharp increase”, with grassland dominating the region, accounting for more than 50% of the total land area, followed by unused land and arable land, forest land and construction land. (2) The most dramatic expansion of the urban agglomeration mainly occurred in the main urban areas of Hohhot, Baotou and other cities and towns, and was mainly the outlying expansion, which was caused by conversion of ecological land such as cropland and grassland. (3) The spatial structure and characteristics of future land use changes will be significantly different under three scenarios in 2025 and 2035. Under the natural development scenario, urban expansion is unconstrained, and and its rapid growth occupied a large amount of ecological land. With certain ecological constraints, the occupation of grassland and forest land was well controlled. Under the economic development scenario, urban expansion will further occupy more unused land and cultivated land. Through the analysis of spatial and temporal pattern evolution and scenario simulation of urban agglomeration expansion in the Yellow River Basin, the study attempts to provide multi-perspective, multi-scenario and multi-choice optional policy decision reference for regional planning, urban spatial planning and regional ecological space protection.