College of Geography and Planning, Chengdu University of Technology, Chengdu, 610059, China.
College of Geography and Planning, Chengdu University of Technology, Chengdu, 610059, China.
J Environ Manage. 2024 Nov;370:122607. doi: 10.1016/j.jenvman.2024.122607. Epub 2024 Sep 20.
Urban expansion has the potentiality to disrupt ecosystems and form highly fragile urban landscapes. However, studies investigating the impact of different urban expansion patterns on the ecological environments are relatively limited. Taking the Yanhe river basin, a typical basin in a loess region, as a case study, we developed an ecological vulnerability assessment system as well as assessed the main drivers of ecological vulnerability for different time periods (1990, 2000, 2010 and 2018). Additionally, we classified each urban expansion region into three different patterns according to the landscape expansion index, and analyzed changes in the ecological vulnerability under these three diverse patterns. Finally, the Kruskal-Wallis rank sum test was applied to compare the factors for the different changes in ecological vulnerability across different urban expansion patterns. Our investigation also aimed to elucidate the impacts of different urban expansion patterns on ecological vulnerability and identify key physical-social-economic-climatic drivers. The results indicate that the ecological vulnerability index (EVI) of the study area is decreasing gradually from the peak value of 0.459 in 2000 to 0.383 in 2018. Habitat quality index is found to be the most influencing factor, followed by aridity index and building density (mean q of 0.53, 0.46, and 0.42, respectively). Our study also reveals that the outlying expansion areas have the greatest increase in EVI at 0.38, with edge and infill expansions at 0.31 and 0.27, respectively. It is also found that when the overall environment is improving, the outlying expansion areas have the smallest decrease in EVI. Initial ecological vulnerability and key drivers may explain this difference. Therefore, results of this study indicate that the ecological impacts of diverse urban expansion patterns are significantly different, among which outlying expansions should receive prioritized attention.
城市扩张有可能破坏生态系统并形成高度脆弱的城市景观。然而，研究不同城市扩张模式对生态环境影响的相对较少。本研究以黄土区典型流域延河流域为例，构建了生态脆弱性评价体系，并对不同时期（1990 年、2000 年、2010 年和 2018 年）的生态脆弱性的主要驱动因素进行了评估。此外，我们根据景观扩展指数将每个城市扩展区域分为三种不同的模式，并分析了这三种不同模式下生态脆弱性的变化。最后，应用 Kruskal-Wallis 秩和检验比较了不同城市扩张模式下生态脆弱性变化的因素。我们的研究旨在阐明不同城市扩张模式对生态脆弱性的影响，并确定关键的物理-社会-经济-气候驱动因素。研究结果表明，研究区的生态脆弱性指数（EVI）从 2000 年的峰值 0.459 逐渐降低到 2018 年的 0.383。栖息地质量指数被发现是最具影响力的因素，其次是干旱指数和建筑密度（均值 q 分别为 0.53、0.46 和 0.42）。我们的研究还揭示了，外围扩张区的 EVI 增加最大，为 0.38，边缘和填充扩张区分别为 0.31 和 0.27。此外，还发现，当整体环境改善时，外围扩张区的 EVI 下降幅度最小。初始生态脆弱性和关键驱动因素可以解释这种差异。因此，本研究结果表明，不同城市扩张模式对生态的影响存在显著差异，其中外围扩张应优先考虑。
