The application of GIS viewable area analysis based on algorithm in landscape planning and design

To provide theoretical guidance for visual domain analysis in landscape planning of scenic spots, this study improves the traditional R2 algorithm, which is computationally intensive for complex terrains. By retaining its core framework and introducing linear interpolation for terrain data, the algorithm now uses a point-by-point scanning and equal-step line-of-sight segmentation strategy. Visibility is determined by considering both the previous point’s visibility and terrain structure. The improved algorithm was implemented and tested on high-performance computers using Geographic Information System (GIS) platforms such as ArcGIS, with real-world terrain data from scenic spots. Results show significantly improved efficiency, with execution times of 3.21, 2.50, and 1.80 s for mountainous, hilly, and plain terrains, respectively. The visual field shape is more circular, with a highest roundness of 103, lowest deviation of 1.3, and highest jaggedness of 41. Compared with other algorithms, it yields larger viewable areas and more accurate spatial visibility. Based on the viewable area analysis in Huashan, a new viewpoint with a visibility value of 0.82 was added to the design, offering scientific and effective support for scenic spot layout planning.