基于最优格网天水市景观脆弱性时空变化特征

[目的]科学评估高原与平原交错区域的景观脆弱性对区域生态调控具有重要意义。[方法]利用天水市数期土地利用/覆盖（LUCC）数据，构建基于景观指数的脆弱性评估模型，探究最优格网下区域景观脆弱性的时空分布格局，地域差异性及景观脆弱性变化情况。[结果]结果表明：天水市景观脆弱性分析最佳格网为4km，1990-2020年，天水市景观类型变化较为明显，主要景观类型以耕、林、草为主，建设用地面积增速最快，耕地面积转出较多，其余面积相互转换。景观脆弱性呈整体下降趋势，等级以较高，中等脆弱为主。脆弱等级面积转移以相邻等级为主，跨级转移较少，且转移面积较小。空间上呈显著的正相关性，局部空间自相关模式变化不大，空间分布稳定性较强。基于不同等级下的脆弱性特征，对天水市未来的环境所存在隐患及恢复生态环境的管理提出了对策建议。[结论] 通过天水市景观脆弱性的时空演变机制为未来生态治理策略和类似地区土地资源的高效使用提供科学的建议和方向。

Temporal and spatial variation characteristics of landscape vulnerability in Tianshui City based on the optimal grid

[Purpose] Scientific assessment of landscape vulnerability in the intertwined region of plateau and plain is of great significance for regional ecological regulation.[Method] Based on the land use/cover (LUCC) data of Tianshui City of several periods, a vulnerability assessment model based on landscape index was constructed to explore the spatial and temporal distribution pattern, regional differences and changes of landscape vulnerability under the optimal grid.[Results] The results show that the optimal grid for landscape vulnerability analysis in Tianshui City is 4km. From 1990 to 2020, in Tianshui City, the landscape type change is obvious, the main landscape type is dominated by ploughing, forest, grass. The fastest growth rate of the area of land for construction, the area of arable land is transferred out of the area of the more, and the rest of the area is converted to each other. The overall trend of landscape vulnerability is decreasing, with higher and medium fragility being the main levels. The area transfer of vulnerability level is mainly based on adjacent levels, with less cross level transfer and smaller transfer area. There is a significant positive correlation in space, with little change in local spatial autocorrelation patterns and strong stability in spatial distribution. Based on the vulnerability characteristics at different levels, countermeasures and suggestions are proposed for the management of potential environmental hazards and restoration of the ecological environment in Tianshui City in the future.[Conclusion] Through the spatiotemporal evolution mechanism of landscape vulnerability in Tianshui City, this paper provides scientific suggestions and directions for future ecological governance strategies and efficient use of land resources in similar areas.