Modelling visual complexity of landscapes

© 1991 Colina ThomsonIn the past, development projects such as transmission lines and other facilities have been constructed to meet the criterion of lowest cost. However, increasing community concern for the environment has led to changes in this attitude. In particular, concern over the visual impact of facilities such as transmission lines has led to the development of techniques to enable planners to assess the effect of these projects on the visual quality of the landscape. This study commences with a discussion of the techniques which have been developed to quantify the visual environment. The development of a computer-based method of analysis of the visual effect of transmission lines, devised by Hadrian et al (1988), is examined in detail. The importance of visual complexity of a landscape as a measure of the ability of the landscape to absorb changes is also examined. In general the study focuses on the development of a method for determining the visual complexity of a landscape scene from biophysical characteristics of the landscape. Two landscape areas were selected for the study which included three major landscape types of interest to transmission line planners. The landscaped scenes to be studied in each of these areas were photographed and their complexities as perceived by observers were determined. A series of measurements of biophysical data for the scenes was made using two methods which involved taking physical measurements directly from the photographs. Measurements for each scene were also taken from a Geographic Information System databases of the areas. These various biophysical measurements were then correlated with the perceived complexity and a number of models for the perceived complexity were developed. The best correlations were found to be those which related perceived visual complexity to landscape features recorded in the Geographic Information System database