A geospatial indicator for assessing urban panoramic views

Abstract

We propose a general methodology for the visibility analysis of a selected landscape area, unit or set of features. Its initial field of application is in panoramic views of towns and cities, a dimension of landscape to which varied approaches have been made in recent years, both in iconographic studies and urban planning. The procedure is based on the calculation of visual exposure and includes two additional factors, namely the average vertical angle over the study area and the observation distance. The first is obtained from an extension to the visual exposure algorithm, and the second is evaluated through a weighting curve based on the ability to perceive details of the subject of interest. The result is an indicator we have called View Generation Potential (VGP), which assigns a value to each point in the territory on the basis of its capacity to produce panoramic views of the study area (town or city). The method is easy to use and sources can be readily accessed. VGP can provide useful information for decision-making in urban and land-use planning, which can be integrated into multi-criteria studies and enables the aesthetic and cultural qualities of the landscape of towns and their surrounding areas to be taken into consideration. It can also be used in the management of urban growth via the generation of land-use suitability maps, the treatment of free spaces and the creation of viewpoints.