A Method of Evaluating Visual Accessibility to Urban Parks

Urban parks are essential open spaces for citizens. The accessibility is an important index to measure their perception of urban parks. However, most of the current studies are based on traffic accessibility (distance, time or cost) rather than the visual one. For this reason, visual accessibility is established in the areas around the urban parks, considering the ground elevation, building height, building orientation, distance to the parks, and views of the park. The concept of visual accessibility is put forward and the method is also developed to evaluate the visual accessibility including two-dimension visual accessibility (V2D) and three-dimension visual accessibility (V3D) in the areas around urban parks based on whether the sight line can reach the urban parks, the visual clarity and the exposure of the urban parks. Taking the Shaping Park in Chongqing as an example, this research calculates the visual accessibility within 1,000 meters around the park with the ArcGIS. The field survey shows that the calculation results with this method are consistent with the reality, suggesting that this method is feasible. Compared with V2D, V3D is more objective and accurate as it takes into account the building layout, height and orientation. Evaluating visual accessibility is a new idea in the study of comprehensive accessibility of urban parks, which is conducive to assessing the service efficiency of urban parks and provides a scientific basis for improving the rationality and fairness of urban parks.