A GIS-based Algorithm for Visual Exposure Computation: The West Lake in Hangzhou (China) as Example

Abstract

Visual perception is crucial in landscape experience. Therefore, visual landscape research is an important field of inquiry that needs further development and applications (NIJHUIS 2011), and visibility analysis is the basis for further research. There are many methods and applications of landscape visibility analysis that have been developed and applied in the past decades. The pioneering work of Llobera explores the concept of “visual exposure”. He defined the visual exposure (V-E) as a measure of the visible portion of whatever is the focus of the investigation, which is about the surface area covered on the retina (LLOBERA 2003). In this research, a newly developed V-E computation algorithm for complex environments has been developed, which enables the analysis of views from multiple viewpoints. The West-Lake, a UNESCO world heritage site in Hangzhou (China), is used as a case study to compute the V-Es’ value for viewpoints on routes beside and around the lake. Finally, the method’s accuracy and the algorithm’s adoption potential have been evaluated.