基于空间距离指数的青藏高原生态敏感性综合评价及时空演变分析

生态敏感性是生态系统对外界压力的适应性及遭受破坏的恢复力，开展生态敏感性评价是识别区域生态环境问题的有效手段之一。根据青藏高原的区域特性和主要生态环境问题，在定量构建土地荒漠化敏感性、水土流失敏感性、滑坡灾害敏感性和冻融侵蚀敏感性的基础上，通过空间距离指数法对青藏高原生态敏感性进行综合评价，并采用空间自相关分析和生态敏感性变化模式分析，探讨其时空演变特征和保护管理区划。结果表明：（1）青藏高原综合生态敏感性由西北向东南递减，极度和重度敏感区主要集中在西北部和高大山脉区，不敏感区主要集中在东南部；（2）2000-2018年间青藏高原综合生态敏感性指数值从1.49上升到1.51，表明该区域生态敏感性逐步下降，生态环境改善明显；（3）青藏高原生态敏感性存在显著的空间正相关，低-低聚集网格数量波动上升，从2000年的7277增至2018年7357，表明青藏高原部分地区的生态环境仍存在着一定恶化的风险；（4）根据区域生态敏感性变化模式分析，将青藏高原划分为严格保护区、生态退化区、潜在治理区、生态改善区和综合发展区五个区域，并提出了相应保护与管理对策。研究结果可以为青藏高原生态保护和可持续发展提供参考，从而有效推动保护管理措施的制定。

Comprehensive evaluation and spatio-temporal variations of ecological sensitivity on the Qinghai-Tibet Plateau based on spatial distance index

Ecological sensitivity refers to the adaptability of an ecosystem to external pressure or interference and the corresponding resilience after devastation, and it is one of effective approaches to identify ecological and environmental problems. According to the regional characteristics and the main ecological problems on the Qinghai-Tibet Plateau (QTP), the ecological sensitivity was comprehensively evaluated in this study, by using a spatial distance index system based on land desertification sensitivity, soil erosion sensitivity, landslide sensitivity, and freeze-thaw erosion sensitivity. Moreover, the spatio-temporal variations of ecological sensitivity and conservation regionalization schemes were discussed through spatial autocorrelation and ecological sensitivity change pattern analysis. The results showed that:(1) the comprehensive ecological sensitivity on the QTP decreased from northwest to southeast, and the extremely and severely sensitive areas were mainly concentrated in the northwest and high mountain regions, while the insensitive areas were mainly distributed in the southeast. (2) From 2000 to 2018, the average value of comprehensive ecological sensitivity index on the QTP increased from 1.49 to 1.51, suggesting that the ecological sensitivity gradually decreased and the environment improved significantly. (3) The ecological sensitivity of the QTP had a significantly positive spatial correlation, and the number of low-low (L-L) aggregation grids fluctuated from 7277 in 2000 to 7357 in 2018, indicating that the ecological conditions of the QTP contained a certain risk of deterioration. (4) Based on the analysis of regionally ecological sensitivity change patterns, the QTP could be divided into five categories:strict protection region, ecological degradation region, potential conservation region, ecological improvement region and integrated development region, and the corresponding conservation regionalization schemes were suggested. These results could provide a reference for ecological protection and sustainable development on the QTP, thus effectively promoting the formulation of conservation and management measures.