Abstract:

As the premise and foundation of high-quality development, the construction of ecological security pattern can not only alert potential major ecological environmental problems, but also help maintain the health and stability of the ecosystem. In this paper, Gansu section of the Yellow River basin was taken as the study region, and the ecological sources were identified and classified by using morphological spatial pattern analysis (MSPA) and combining the ecological quality assessment based on the InVEST model and the spatial distribution of ecological services. Moreover, by integrating geographic and socio-economic factors to build a resistance surface, the ecological corridors were extracted based on random walk theory, and the key ecological security pattern elements such as pinch points and barrier points were identified according to circuit theory. On this basis, combined with the territorial spatial planning of Gansu Province, the ecological security pattern of the study region was comprehensively constructed. The results showed that the ecological sources were mainly distributed in the southern and eastern edges of the study region, unevenly distributed and fragmented, with a total area of 1.08×10⁴ km². Among them, the area of core ecological sources was 2.45×10³ km². There were 257 ecological corridors, with a total length of 6.06×10³ km, including 22 key terrestrial ecological corridors with a length of 50.7 km and 40 key river ecological corridors with a length of 494 km. The study region contained 109 pinch points and 37 primary ecological barriers, with an area of 206 km² and 1.59×10³ km², respectively. Furthermore, the ecological security pattern of “one axis, two cores and multiple areas” had been constructed comprehensively. The “one axis” was the axis of ecological protection, restoration and ecological construction. The south and north of this axis undertook important tasks of ecological security maintenance and ecological construction under the premise of ecological protection and restoration. The “two cores” were the two ecological protection core areas located in the Weihe River and Taohe River basins, which required priority given to ecological protection. The “multiple areas” were Gannan water conservation area, Datong River and Zhuanglang River ecological restoration area, Longdong ecological restoration area and Longxi ecological construction area. This study combined MSPA and InVEST models for ecological sources identification, which complemented each other in terms of analysis mechanism and identification process, and to simulate population migration and dispersal based on circuit theory, significantly improving the accuracy of identification of ecological sources and corridors. The study can provide references for territory development, ecological protection and ecological security maintenance of the Gansu section of the Yellow River basin.

Key words: ecological security pattern, morphological spatial pattern analysis, ecosystem service, circuit theory, habitat quality

摘要：

作为高质量发展的前提和基础，生态安全格局构建不仅能够警示潜在重大生态环境问题，而且有利于维护生态系统的健康稳定。以黄河流域甘肃段为研究区，采用形态学空间格局分析（MSPA）方法，融合基于InVEST模型的生境质量评估及生态服务功能空间分布，识别生态源地并进行分级。综合自然地理与社会经济因素构建阻力面，依据随机游走理论提取生态廊道，基于电路模型辨识生态夹点、障碍点等关键生态节点，并在此基础上结合甘肃省国土空间规划，构建研究区生态安全格局。结果表明：生态源地主要分布于研究区南部和东部边缘，空间分布不均且破碎化，总面积1.08×10⁴ km²，其中核心生态源地2.45×10³ km²；识别生态廊道257条，总长度6.06×10³ km，其中关键陆地生态廊道22条，长度50.7 km，关键河流生态廊道40条，长度494 km；识别生态夹点109处，面积206 km²，识别一级生态障碍点37处，面积1.59×10³ km²。综合构建了“一轴、两核、多区”的生态安全格局，“一轴”为生态保护、修复与生态建设轴，该轴以南、以北分别承担重要的生态安全维护任务、生态保护与修复前提下的生态建设任务。“两核”分别为渭河与洮河流域的两个生态保护核心区，需要优先进行生态保护。“多区”分别为甘南水源涵养区，大通河、庄浪河生态修复区，陇东生态修复区，陇西生态建设区。本研究将MSPA与InVEST模型相结合进行源地识别，在分析机制与识别过程上互为补充，并基于电路理论模拟种群迁徙与扩散，显著提高了源地与廊道识别的准确性，可以为黄河流域甘肃段国土空间开发、生态保护及生态安全维护提供参考。

关键词: 生态安全格局, 形态学空间格局分析, 生态系统服务, 电路理论, 生境质量