山水资源型城市景观生态风险评价及生态安全格局构建——以张家界市为例

区域生态安全是现代城市健康发展的重要内容,科学认识与评价区域生态风险与构建生态安全格局,有利于综合提升区域生态安全水平。以张家界市2019年高分二号遥感解译数据为基础,使用GIS空间分析与Fragstats软件构建景观生态风险指数,对景观生态风险空间分布特征进行分析;利用最小累积阻力模型(MCR),以9个自然保护地为生态源地,以景观生态风险指数、植被覆盖度、高程、坡度、与道路距离、与水域距离构建阻力面,识别生态廊道与生态节点,构建生态安全格局并提出生态安全保护策略。结果表明：(1)研究区景观生态风险空间差异明显,生态风险呈现“中部、四周低,高值区总体沿澧水水系呈条带状延伸”的空间分布规律;(2)低、较低、中、较高、高生态风险分别占比21.59%、41.79%、22.57%、12.08%、1.98%,其中较低生态风险占比最高,高生态风险占比最低,各区县高生态风险压力排序为：永定区>慈利县>桑植县>武陵源区;(3)研究共识别出生态廊道24条,生态节点47个,生态廊道累积长达872.35km,生态廊道与生态节点分别呈现“三横四纵”、“中多西少,南多北少”的空间分布特征;(4...

Landscape ecological risk assessment and ecological security pattern construction in landscape resource-based city: A case study of Zhangjiajie City

Regional ecological security is an important part of the healthy development of modern cities. 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. Based on the remote sensing interpretation data onto Gaofen-2 of Zhangjiajie City in 2019, this paper used GIS spatial analysis and Fragstats software to construct landscape ecological risk index, and analyzed the spatial distribution characteristics of landscape ecological risk. And the minimum cumulative resistance model is used to construct resistance surface. At the same time, in order to intuitively reflect the magnitude of resistance encountered during species migration, this paper uses 9 natural protected areas as ecological sources, and selects six resistance factors including landscape ecological index, vegetation coverage, elevation, slope, distance from roads, and distance from waters calculate the resistance value. Combining the ecological source area and the minimum cumulative resistance value, Then we identified ecological corridors and ecological nodes, and finally built an ecological security pattern and proposed ecological security protection strategies. This paper takes Zhangjiajie city as an example to verify the function and effectiveness of the method. The results show that:(1) there are obviously spatial differences in landscape ecological risk in the study area, and the ecological risk presents a spatial distribution pattern of "the middle and surrounding areas are low, and the high value area generally extends along the Lishui River in a strip"; (2) Low, relatively low, medium, relatively high, and high ecological risks area account for 21.59%, 41.79%, 22.57%, 12.08%, and 1.98%, respectively, among which the relatively low ecological risk area account for the highest proportion and the high ecological risk area account for the lowest proportion. The order of high ecological risk area pressure is:Yongding District > Cili County > Sangzhi County > Wulingyuan District; (3) The research identifies 24 ecological corridors and 47 ecological nodes. The cumulative length of ecological corridors is 872.35 km. And the spatial distribution characteristics of ecological corridors and ecological nodes are "three horizontal and four vertical" and "they are mainly distributed in the central and southern regions, and relatively few in the western and northern regions"; (4) The study area has formed an ecological security pattern consisting of 9 ecological sources, 47 ecological nodes, 24 ecological corridors and 3 ecological safety areas. On this basis, the protection strategy of ecological security is proposed to provide scientific guidance for the ecological environment construction of Zhangjiajie city.