基于MCR模型与蚁群算法的洮河流域生态安全格局构建

Construction of Ecological Security Pattern of Tao River BasinBased on MCR Model and ant Colony Algorithm

生态安全格局的构建是保障地区生态安全的根本措施,是促进地区经济可持续发展的关键。洮河流域作为黄河上游重要的生态功能区,具有涵养水源、保持水土和生态安全屏障等重要生态功能,对黄河流域生态保护和高质量发展意义重大。受自然和人为因素双重影响,其生态环境脆弱敏感。关于该区域生态环境保护与修复的研究还不够全面,故选择洮河流域为研究区。基于洮河流域的生态特征,将生态系统服务重要性、生态敏感性和景观连通性的评价结果叠加分析,进行生态源地识别;采用最小累积阻力模型与蚁群算法并结合核密度分析方法,识别生态廊道空间范围;采用水文分析法识别生态节点,构建洮河流域生态安全格局。结果表明,(1)洮河流域的生态系统服务重要与极重要区域面积之和约为3.124×10^(4)km^(2),约占研究区面积的69.02%,说明洮河流域生态系统服务价值较高;洮河流域生态敏感性主要以一般敏感和中等敏感为主,总面积约为2.753×10^(4)km^(2),约占研究区总面积的60.81%。(2)景观连通性极重要与重要区域面积为2.022×10^(4)km^(2),约占研究区总面积比例高达44.67%,表明区域景观连通性整体水平较高,但空间分布上不均衡。(3)构建出面积2.174×10^(4)km^(2)的37个生态源地;长度2.649×103km、面积6.671×103km2的49条生态廊道;38个生态节点的点线面网状结构的生态安全格局。研究结果以期为洮河流域生态环境治理与恢复以及区域可持续发展规划提供相关依据。

Construction of ecological security pattern is the key measure of ensuring regional ecological security and promoting the local social and economic sustainable development.As the most significant ecological functional region in the upper reaches of the Yellow River,the Taohe River Basin provides the substantial ecological service functions,e.g.water source protection,soil and water conservation,and ecological sheltering function,which have a tremendous contribution for ecological conservation and high-quality development of the Yellow River Basin.However,there is a lack of understanding of the ecological security pattern in the Taohe River Basin,which was extremely fragile and sensitive under the double stresses of climate change and human activities.Therefore,the ecological source area was identified through overlay analyses of ecosystem services importance,ecological sensitivity,and landscape connectivity;meanwhile,the spatial range of ecological corridor was withdrawn by the Minimum Cumulative Resistance(MCR)model and ant colony algorithm in combination with kernel density estimation.In addition,ecological nodes were identified by the hydrological analysis method.The results showed that(1)important and extremely important regions of ecological services in the Taohe River basin covered 3.124×10^(4)km^(2),accounting for 69.02%of the total area,suggesting high ecological service value;and the ecological sensitivity was dominated by the average and medium levels,covering 2.753×10^(4)km^(2)which accounted for 60.81%.(2)the area of important and extremely important regions of landscape connectivity was 2.022×10^(4)km^(2)accounting for 44.67%,suggesting high landscape connectivity but low evenness in a spatial pattern.(3)The 37 ecological source regions with an area of 2.174×10^(4)km^(2),49 ecological corridors with a length of 2.649×10^(3)km and an area of 6.671×10^(3)km^(2),and 38 ecological nodes were identified.The region-corridor-node structure constructed an ecological security pattern in the Taohe River Basin.The results will provide the basis for ecological governance and restoration,and local sustainable development of the Taohe River Basin.