新疆生态脆弱性时空演变特征及其对干旱的响应
Spatiotemporal evolution of ecological vulnerability in Xinjiang and its response to drought
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摘要: 随着全球气候变暖,干旱对生态系统结构和功能构成了巨大威胁,剖析生态系统脆弱性时空演变特征及其对干旱的响应,对于实现区域高质量可持续发展至关重要。该文以新疆为研究区,基于生态敏感性-生态恢复力-生态压力度(ecological sensitivity-ecological recovery-ecological pressure,SRP)模型构建生态脆弱性评价指标体系,结合局部空间自相关、变异系数、Slope趋势分析和Hurst指数等方法,评价2000—2020年生态系统脆弱性并预测未来变化趋势,利用标准化降水蒸散指数(standardized precipitation evapotranspiration index,SPEI)探究干旱对生态脆弱性的影响。结果表明: ①新疆地区整体生态脆弱性较高,脆弱性空间分布存在明显的地域差异及空间聚集性特征; SPEI值以年均0.093 9的速率呈下降趋势,区域干旱化加重趋势明显; ②干旱与生态脆弱性呈负相关的面积占比54.1%,即随着区域水分条件改善,大部分地区生态脆弱性降低; ③生态脆弱性的稳定分布区域面积占比77.8%,以重度和极度脆弱区为主,未来新疆大部分地区(61.3%)生态脆弱性呈降低趋势,生态环境质量得到改善。研究结果有利于深化对新疆生态系统脆弱性状况及其驱动机制的认识,为提高区域生态系统对环境变化的适应能力提供科学参考和决策依据。Abstract: Global warming has exacerbated drought conditions, posing a significant threat to ecosystem structures and functions. Analyzing the spatiotemporal evolution of ecological vulnerability and its response to drought plays a significant role in achieving regional high-quality and sustainable development. With Xinjiang as the study area, this study constructed an assessment index system for ecological vulnerability based on the ecological sensitivity-resilience-pressure (SRP) model. Using methods like local spatial autocorrelation, coefficient of variation, slope trend analysis, and Hurst exponent, this study assessed the ecological vulnerability in Xinjiang from 2000 to 2020, followed by future trend prediction. Moreover, this study explored the impacts of drought on ecological vulnerability using the standardized precipitation evapotranspiration index (SPEI). The results indicate that the overall ecological vulnerability was relatively high in Xinjiang, with its spatial distribution characterized by significant regional differences and spatial aggregation. The SPEI value showed a downward trend at an average annual rate of 0.093 9, suggesting a significant worsening trend of regional aridification. The area featuring a negative correlation between drought and ecological vulnerability represented 54.1 %, indicating that ecological vulnerability in most areas decreased with improved regional moisture conditions. The stable distribution area of ecological vulnerability constituted 77.8 %, dominated by severely and extremely vulnerable areas. In the future, the majority of Xinjiang (61.3 %) is projected to witness decreased ecological vulnerability and enhanced ecological quality. Overall, the results of this study deepen the understanding of the status and driving mechanism of ecological vulnerability in Xinjiang, providing a scientific reference and decision-making basis for enhancing the adaptability of regional ecosystems to environmental changes.
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