Landscape Visual Affordance Evaluation at a Regional Scale in National Parks: A Case Study of the Changhong Area in Qianjiangyuan National Park

National parks play a vital role in safeguarding natural scenery, maintaining ecological integrity, and preserving cultural heritage, while simultaneously offering valuable opportunities for recreation and education. Among the diverse resources provided by national parks, visual landscape resources hold particular significance due to their capacity to inspire, educate, and enhance aesthetic appreciation. However, assessing and managing these resources remain challenging, as they span both the physical attributes of the landscape and the human visual perception process. This study aims to develop a theoretical and practical framework for evaluating the “landscape visual affordance” of national parks. Grounded in ecological psychology’s affordance theory, the proposed approach integrates physical affordance and sensory affordance, encompassing both the objective physical attributes of the landscape and the subjective processes of human perception. Drawing on a multi-dimensional set of indicators, the research quantifies physical features—such as topography, land use, vegetation cover, and landscape structure—as well as sensory dimensions, including visibility, visual prominence, and viewing frequency. These elements are synthesized into a landscape visibility assessment model built upon the affordance theory framework. The results demonstrate that landscape visual affordance effectively identifies landscape patches with varying degrees of visual quality and importance within national parks and other protected areas. By providing robust support for management decisions—such as zoned protection, optimizing recreational facilities, and evaluating visitor carrying capacity—this model offers new insights and practical guidance for the sustainable planning and management of landscapes in national parks and other ecologically critical regions.