Sun Mingyue, Liu Hongguang, Dang Yingsheng, Gong Ping, Li Pengfei, Fang Rui, Cao Huan, Li Xiang, Xia Hanji, Ye Fuhai, Guo Yong
College of Water Conservancy and Architectural Engineering, Shihezi University, Shihezi, Xinjiang Province, China.
Hydrology and Water Resources Management Center of the Second Division of Xinjiang Production and Construction Corps, Tiemenguan, Xinjiang Province, China.
PLoS One. 2025 May 7;20(5):e0321762. doi: 10.1371/journal.pone.0321762. eCollection 2025.
The rapid development of oasis desert cities adversely affects fragile ecosystems, preventing regional sustainable development. This study investigates the spatiotemporal evolution characteristics and potential quantitative relationship between oasis landscape structure (OLS) and the ecological risk index (ERI) and the trend in different development scenarios in Tiemenguan City, a typical oasis city in an arid zone in northwestern China, from 1990 to 2020. We calculated the ERI thresholds for different landscape types, classified ecological risk levels, and examined the factors influencing ecological risk. The normalized difference vegetation index (NDVI) thresholds were NDVI ≥ 30% for oases, 10% <NDVI < 30% for transition zones, and NDVI ≤ 10% for desert areas. Under government control, transitions from cropland, woodland, and grassland to built-up and unused land decreased by 20%, whereas conversions from unused land to cropland, woodland, and grassland increased by 30%. The results showed the following: (1) The oasis area expanded continuously from 175.5 km2 to 345.3 km2 during 30 years. The transition and desert zones decreased by 49.7% and 37.9%, respectively. The ERI decreased and was strongly correlated with the OLS. The thresholds of the ERI in the oasis zone-transition zone and the transition zone-desert zone were 0.08-0.085 and 0.111-0.118, respectively. (2) Socioeconomic factors, including infrastructure expansion, population density, and GDP, were dominant influences, contributing 64% to the ERI, whereas the influence of natural factors such as climate declined. (3) The low-ERI areas increased by 3.3% under government control, and the transition zones increased significantly, slowing the growth rate of the oasis zone. This study quantitatively evaluated the landscape types' ecological risk levels and analyzed the effects of dynamic migration on the landscape type stability. This paper provides a systematic research framework for ecological risk assessment of various landscape types in oasis desert cities and a scientific basis for ecological conservation and related research.
绿洲沙漠城市的快速发展对脆弱的生态系统产生不利影响，阻碍了区域可持续发展。本研究调查了中国西北干旱区典型绿洲城市铁门关市1990年至2020年绿洲景观结构（OLS）与生态风险指数（ERI）之间的时空演变特征、潜在定量关系以及不同发展情景下的趋势。我们计算了不同景观类型的ERI阈值，划分了生态风险等级，并研究了影响生态风险的因素。归一化植被指数（NDVI）阈值为：绿洲区NDVI≥30%，过渡区10%＜NDVI＜30%，沙漠区NDVI≤10%。在政府管控下，耕地、林地和草地向建设用地和未利用地的转变减少了20%，而未利用地向耕地、林地和草地的转变增加了30%。结果表明：（1）30年间绿洲面积从175.5平方公里持续扩大到345.3平方公里。过渡区和沙漠区分别减少了49.7%和37.9%。ERI降低且与OLS显著相关。绿洲区 - 过渡区以及过渡区 - 沙漠区的ERI阈值分别为0.08 - 0.085和0.111 - 0.118。（2）包括基础设施扩张、人口密度和国内生产总值在内的社会经济因素是主要影响因素，对ERI的贡献率为64%，而气候等自然因素的影响下降。（3）在政府管控下，低ERI区域增加了3.3%，过渡区显著增加，绿洲区的增长速度放缓。本研究定量评估了景观类型的生态风险等级，分析了动态迁移对景观类型稳定性的影响。本文为绿洲沙漠城市各种景观类型的生态风险评估提供了系统的研究框架，为生态保护及相关研究提供了科学依据。
