基于供需视角的黄河流域甘肃段生态安全格局识别与优化

利用多源空间数据,计算生态系统服务的高值区,识别生态源地,在计算土地利用程度、地均GDP和人口密度确定生态系统高需求区的基础上,通过夜间灯光数据修正生态阻力面系数,利用最小累积阻力模型提取源地与高需求区之间的生态廊道,以此构建并优化区域生态安全格局。结果表明：(1)黄河流域甘肃段生态源地总面积4.59×10⁴ km²,占研究区总面积的32.1%,集中分布于甘南和陇东中部地区。(2)生态系统服务高需求区总面积2.18×10⁴ km²,占研究区总面积的15.2%,主要集中于陇中及陇东的城市建成区,生态系统服务供应和需求空间匹配度差。(3)生态廊道总长度2908.3 km,整体格局上形成了东西向与南北向两大主要廊道轴线。生态廊道的识别中重点考虑了生态需求空间,提出了基于"两带-三区"的流域生态安全格局优化建议。

Ecological safety pattern identification and optimization based on the ecological supply and demand in Gansu section of the Yellow River Basin

The ecological protection and high-quality development of the Yellow River Basin has been determined as a major national strategy. Ecological security pattern is considered as one of the three strategic patterns of land and space development and protection, which refers to the overall health, sustainability and perfect ecological functions of the ecosystem. Scientific understanding and evaluation of regional ecological risks and construction of ecological security pattern are conducive to comprehensively improving the level of regional ecological security. At present, for the construction of ecosystem security pattern at home and abroad, a relatively perfect pattern construction model with "source identification, resistance surface construction, corridor extraction and determination of security pattern" as the basic framework has been formed for research. In this paper, InVEST (Integrate Valuation of Ecosystem Service and Tradeoffs Tool), ArcGIS and other software are used to select four indicators that can represent the main ecological contradictions in Gansu section of the Yellow River Basin, including water conservation volume, carbon fixation and oxygen release volume, soil conservation volume and ecological and environmental quality. The index importance method is used to extract the ecological source, as well as the land use degree, population density and land average GDP to identify the spatial pattern of ecosystem service demand. Finally, the MCR (Minimum Cumulative Resistance) model is used to extract the ecological corridors between the source areas and between the source areas and the high-demand areas, thereby identifying and constructing the regionally ecological security pattern. The results show that:(1) the total area of ecological source in Gansu section of the Yellow River Basin is 4.59×10⁴ km², accounting for 32.1% of the total area of the research area, mainly distributed in the central, southern and western Gansu Province. (2) The total area of high demand area for ecosystem services is 2.18×10⁴ km², accounting for 15.2% of the total area of the research area, mainly distributed in the urban built-up areas of the central and eastern Gansu Province, with poor spatial matching between ecosystem service supply and demand. (3) The total length of the ecological corridor is 2908.3 km. From the overall pattern, it forms two main corridor axes in east-west and north-south directions. In this research, the ecological demand space is taken into account in the identification of ecological corridors, and more attention is paid to the areas with high demand and low service, and then the optimization suggestions of watershed ecological security pattern based on "two belts-three areas" are put forward, hoping to provide scientific reference for establishing watershed ecological comprehensive management mechanism and promoting watershed protection, governance and high-quality development.