Abstract:In this research, a synthetic assessment system is developed in order to evaluate the eco-sustainability of roads and their spatial variability in a tourism area. A case study in Lijiang County, located in the northwest of Yunnan Province, is described. The tourism industry in this study area has developed rapidly in the past few years. The assessment employs tools such as landscape pattern metrics, total variation index, and stability coefficients. The study's results reveal that: (1) generally, the roads have helped to develop the tourism industry in Yulong County, and their impact on the environment is minimal; (2) there is significant spatial variability in eco-sustainability among roads; and (3) factors influencing road ecological sustainability include the intensity of tourist activities, the slope of the roads, the geological structure along the mountain roads, and the ecosystem sensitivity along the roads. The methodology has made major advances in five main areas. First, it considers both of the decisive factors of eco-sustainability in a tourism area-the development of a tourism industry, and its influence on ecosystems. These two form a coherent whole. Second, the methodology evaluates two aspects of road connectivity features: the internal rationale of road design and construction, and the external interference of geological hazards. The third highlight of this research is the establishment of a three-layer evaluation system of ecological effects, which includes the spheres of influence of an ecosystem, its pattern, and ecological factors. Fourth, the evaluation of road eco-sustainability in a tourism area would benefit by showing the spatial distinction of eco-sustainability of different roads. Fifth, the support vector machines model used in this paper could exclude the interference with the man-induced factor when defining weight for the category index. The keys to evaluate the eco-sustainability of the roads in a tourism area are the rational choice of indexes and the identification of thresholds. For instance, besides their tourism functions such as communication, they also perform many social and economic functions. In addition, the impacts of ecological factors such as the weather, soil, water, and creatures surrounding the roads should be considered as much as possible in the evaluation. But since some factors are difficult to quantify or statistics difficult to obtain, future research will focus on improving the evaluation indexes further. To this end, we should carry out experimental studies in order to identify more reasonable ecological thresholds. The ultimate purpose of our research is to provide references for road construction in the tourism area and for the protection of ecological integrity. Therefore, in constructing roads in the tourism area, we should first plan and design road levels in light of the development plan and trend of the tourist area and the tourist capacity of its roads. Next, in road planning and designing, we should consider the slope-elevation relationship and try to circumvent areas where geological disasters are likely to occur, thus improving road safety and comfort. Finally, we should follow the principle of giving priority to conservation and try not to let the roads run across ecologically sensitive areas. Meanwhile, we must consider restoring the disabled ecological functions and improving the habitat quality on the sides of existing roads, and propose measures for ecological restoration.