Bird eye analysis of skyline views from an elevated recreation trail—The case of the Fu Forest Trail, Fuzhou, China

Abstract

The Fu Forest Trail in the Chinese city of Fuzhou, completed in 2018, is a new pedestrian recreational system in an urban mountain forest area. Construction of the walkway was guided by identification of key sightlines between the mountains and the city. These sightlines controlled the interaction with the skylines around the walkway, building height, volume and density, and while also assisting with coordinated development of mountain forest area and surrounding urban areas. In the present study, a three-dimensional (3D) city model of the urban area with Fu Forest Trail was developed based on Geographic Information System (GIS). Combined with the principle of the real vision of human eyes, we obtained six skylines correspond to three observation areas from viewpoints along the forest trail. At the same time, the three indicators on the skyline aesthetic evaluation of silhouette complexity, layering equilibrium degree, and fractal dimension have been evaluated. Analysis led to the identification of several problems in the skyline around Fu Forest Trail: the outline is too flat, the proportion of layers is unbalanced, and there is a lack of satisfactory fluctuations and influential high-rise buildings. During the past 20 years, high-intensity development of real estate projects had resulted in a disproportionate share of excessively high, very large, and homogeneous residential buildings around the mountainous area. Buildings almost fully surround the mountain, which also explains the latter problem. We suggest that the government takes zonal control measures to restrict the development of the surrounding mountains in different gradients according to the distance from the mountains. Our findings can provide support for further study and governmental decision-making, while also providing inspiration for similar projects in China and elsewhere.