最优尺度下新安江流域景观生态安全格局及其影响因素

新安江流域作为首个跨省生态补偿政策试点,其政策实施对于地区城市整体生态治理具有正向促进作用,分析新安江流域城市政策实施前、中、后期的景观生态风险时空演变趋势及驱动因素,可为该地区及同类区域生态治理及风险防范提供科学支撑。基于2000、2010、2020年三期土地利用遥感数据,寻求评价景观生态风险的最优尺度,分析其时空演变趋势,并借助地理探测器计算空间因子的影响程度。研究表明:研究区最优研究尺度为粒度70 m、幅度11 km;2000-2020年,研究区景观生态风险显著降低,较高以上风险区面积大幅缩减,生态风险呈显著的空间正相关性,且相关程度不断减弱,高值聚集区逐渐减少;研究区内土地利用强度与坡度对景观生态风险驱动效应最强,各因子交互探测时可显著提高解释能力。研究区各市景观生态风险空间差异显著,需加强对草地、水域景观整体性的维护,进一步加强新安江流域城市生态稳定性,同时应考虑地区用地结构及风险状况,针对性采取风险治理措施。

Landscape Ecological Security Pattern and Its Influencing Factors in Xin''an River Basin on the Optimal Scale

Xin''an River Basin is the first pilot area where cross-provincial ecological compensation policy is adopted, and the implementation of the policy has positively promoted the overall urban ecological governance in this region. By analyzing the spatio-temporal evolution of landscape ecological risks and its driving factors in the early, middle, and later periods of the policy implementation, we can provide scientific support for ecological governance and risk prevention in the region and similar regions. This paper seeks the optimal scale for evaluating the ecological risk of landscapes, analyzes its spatial and temporal evolution trends, and calculates the influence degree of spatial factors with the help of geoprobes based on the three-period remote sensing data of land use in the years 2000, 2010, and 2020. The optimal study scale in the study area is 70 m in granularity and 11 km in amplitude; From 2000 to 2020, the ecological risk of the landscape in the study area has been significantly decreased, with higher risk areas greatly reduced. The ecological risk shows a significant positive spatial correlation, with the degree of correlation diminishing, and the area of high aggregation is gradually shrinking. Land use intensity and slope have the strongest driving effect on landscape ecological risk in the study area, and the validity is significantly improved when the factors are detected interactively. There are significant spatial differences in landscape ecological risks among the cities in the study area, and it is necessary to strengthen the integrated maintenance of grassland and water landscape to further enhance the urban ecological stability of Xin''an River Basin, and at the same time, the risk management measures should be taken in a targeted manner in view of the regional land use structure and the risk situation.