岷江流域生态安全格局评价与优化——基于最小累积阻力模型和重力模型

生态安全格局评价是维护生物多样性、改善环境质量的重要途径,对维持区域持续发展具有重要意义。以岷江流域为研究区,综合运用土地利用和归一化植被指数（NDVI）等数据,基于生态系统服务对岷江流域进行生态重要性分析,将生态极重要区识别为生态源地,采用最小累积阻力（MCR）模型中成本路径法提取潜在廊道,结合重力模型提取重要廊道和重要节点,从而实现对研究区生态安全格局的刻画,进而对岷江流域生态安全格局评价并提出优化建议。研究结果表明：（1）岷江流域安全等级总体较好,较高生态安全和高生态安全的面积占研究区面积的55.02%。（2）从空间上看,研究区内重要生态源地面积为818.32km²,破碎化严重,集中分布在岷江流域上游林地区;廊道共190条,总长度为19633.96km,其中重要廊道41条,呈半环状分布于上游和下游段;生态节点共117个,集中分布在上游段南部-西南部。（3）参考生态阻力和廊道节点空间分布特征,划分岷江流域"四区两带"生态安全格局并提出分区管控措施和相关建议。以期研究结果和调控路径可对完善岷江流域生态安全格局、保护生物多样性和增强水土保持有一定的借鉴意义。

Evaluation of ecological security pattern and optimization suggestions in Minjiang River Basin based on MCR model and gravity model

Assessing ecological security pattern is an important approach to conserve biodiversity and improve environment and is of significance to maintain regionally sustainable development. This study takes the Minjiang River Basin as the study area. Based on the method of ecosystem services, the study makes a comprehensive use of such data as land use and NDVI for the purpose of analyzing the ecological importance of the Minjiang River Basin. According to the analysis results, the ecologically important area is recognized as the ecological source. It adopts the cost path method in MCR model to extract potential corridors, combined with the gravity model to extract important corridors and important nodes to evaluate and optimize the ecological security pattern of Minjiang River Basin. The results show that (1) the overall safety level of the Minjiang River Basin is relatively good, and the area of higher ecological safety and high ecological safety accounts for 55.02% of the study area. (2) Spatially, the importantly ecological source covers an area of 818.32 km² and is severely fragmented, which concentrated in the forest area in the upper reaches of the Minjiang River Basin. There are 190 corridors with a total length of 19633.96 km, including 41 important corridors, which are distributed in a semi-ring of the upper and lower reaches; there are 117 ecological nodes, which are concentrated in the south and southwest of the upper reaches. (3) Considering the spatial distribution characteristics of ecological resistance and corridor nodes, the ecological security pattern of four zones and two belts in the Minjiang River Basin is designated and the zoning control measures and restoration recommendations are proposed. The results of the study and the regulatory pathways contribute to improving the ecological security pattern, protecting biodiversity and enhancing soil and water conservation in the Minjiang River Basin.