Abstract:

The period from 2000 to 2020 was a period of rapid economic and social development in China, during which the uncontrolled expansion of ecological zones caused great damage. To achieve high quality and sustainable development, protection and restoration are required. Accurate identification of the spatial distribution of regional ecological vulnerability and its evolutionary pattern is an important premise and foundation for the precise implementation of ecological protection and restoration measures. Currently, there is a lack of research on the ecological vulnerability of plateau pastoral areas, and few studies have analyzed in detail the current ecological status and pressure faced by a particular region. The Sanjiangyuan region is an important ecological source and water-supply area in China. In order to investigate the spatial distribution and spatial-temporal evolution of ecological vulnerability in this area, this study, based on the model of “sensitivity-recovery-pressure”, selected 14 indicators that have an important influence on the ecology of the Sanjiangyuan region, and combined the principal component analysis method and geographic detector to analyze the ecological vulnerability of the area in 2000, 2010 and 2011, as well as the ecological stress of the area. Combined with principal component analysis and geodetector, we analyzed the ecological vulnerability of the region in 2000, 2010 and 2020, and revealed its driving mechanism. The results showed that (1) the ecological vulnerability of the Sanjiangyuan region is dominated by mild, moderate and severe vulnerability, with an average area share of 34.5%, 29.9% and 28.6% in the three periods, respectively; the spatial distribution of vulnerability is characterized by a pattern of “high in the north and low in the south”, with obvious regional differences. (2) From 2000 to 2020, the ecological sensitivity, resilience and vulnerability of the Sanjiangyuan region will show a trend of “rising first and falling later”; the ecological pressure degree is in a continuous upward trend with the economic and social development. (3) The spatial pattern of ecological vulnerability was relatively stable, with significant spatial clustering characteristics: the high-high clustering area was mainly distributed in the northern region, and the low-low clustering area was mainly distributed in the southern region with high vegetation coverage and high precipitation. (4) Annual precipitation, dryness, relative humidity, and NDVI were the main drivers of ecological vulnerability in the Sanjiangyuan region, with q-values of 0.811, 0.705, 0.614, and 0.574, respectively. Ecological vulnerability is the result of the integrated effects of multiple factors owing to the interaction between different factors. This study provides a basis for the selection of indicators for the assessment of ecological vulnerability in plateau pastoral areas, and a reference value for the identification of ecological protection areas in the Sanjiangyuan region.

Key words: ecological vulnerability, Sanjiangyuan region, SRP model, spatial and temporal distribution, drivers

摘要：

2000－2020年是中国经济社会快速发展的时期，这一时期对生态区的无序扩张造成了极大破坏，为实现高质量、可持续发展，需对其进行保护与修复。精准识别区域生态脆弱性的空间分布及其演变规律，是生态保护和恢复措施精确实施的重要前提和基础。当前对于高原牧区生态脆弱性的研究较为匮乏，并且较少能细致分析某一特定区域当前所处的生态状态和所面临的生态压力。三江源地区是中国重要的生态源地和水源供给地，为探究该地区生态脆弱性空间分布和时空演变规律，基于“敏感性-恢复力-压力度”模型，选取对三江源地区生态具有重要影响力的14个指标，结合主成分分析法和地理探测器，对该地区2000、2010和2020年生态脆弱性进行分析，并揭示其驱动机制。结果表明，1）三江源地区生态脆弱性以轻度、中度和重度为主，三期平均面积占比分别为34.5%、29.9%、28.6%；脆弱性在空间分布特征上表现为“北部高、南部低”的格局，有明显的区域差异性。2）从2000－2020年，三江源地区生态敏感性、恢复力和脆弱性呈“先上升、后下降”的趋势；生态压力度随着经济社会的发展处于持续上升趋势。3）生态脆弱性空间格局相对稳定，具有显著的空间集聚特征，高－高聚集区主要分布在北部地区，低－低聚集区主要分布在植被覆盖率高、降水量大的南部地区。4）年降水量、干燥度、相对湿度和NDVI等是三江源地区生态脆弱性的主要驱动因子，q值分别为0.811、0.705、0.614和0.574。由于不同因子之间具有交互作用，生态脆弱性是多因素综合作用的结果。该研究可为高原牧区生态脆弱性评估提供指标选取依据，并对三江源地区生态保护区域的识别提供参考价值。

关键词: 生态脆弱性, 三江源地区, SRP模型, 时空分布, 驱动因素