Assessment of landscape silhouette value in urban forests based on structural diversity indices

Abstract

Urban forests form an important component of the urban environment. They make a significant contribution to landscape silhouettes due to species diversity and the differences observed within forest communities such as tree composition, size and form. Visual effects such as these are referred as aesthetic value. Therein, quantitative assessments of targeted forest structures that will optimize aesthetic values are vital during urban forest planning. However, the silhouette effect, which is an important component of aesthetic value, has not been extensively studied to date. This study aims to reveal the relationship between forest structure, the visual quality of tree composition and the different forms and sizes that create the silhouette effect. To this end, virtual landscapes of different structures were created using computer-assisted images. The forest structure was characterized by a Form Mingling Index (FMI) and Height Dominance Index (HDI). A Pearson correlation was applied in order to find the relationship between the landscape silhouette values through a perceptual test as well as the FMI and HDI. The results of the analyses showed that there was a strong positive relationship between the FMI and HDI (r = 0.78, r = 0.75, P \ 0.01, respectively) and landscape silhouette values. The combined effect of FMI ? HDI was found to have the highest relationship with landscape silhouette values (r = 0.80, P \ 0.01). In conclusion, FMI and HDI offer a rapid, cost-effective method which can be used by managers to assess the silhouette value of an urban forest landscape.

Effects of Design Proportion and Distribution of Color in Urban and Suburban Green Space Planning to Visual Aesthetics Quality

“…On the one hand, Müderrisoglu and others pointed out that the visual form of trees has a positive and strong correlation to the aesthetic quality of the landscape [40]. Within natural grown forest stands, people tend to prefer a mixed silhouette of trees when studying a landscape visual perception [16]. Diversification of canopy shape can promote the aesthetic quality of landscape.…”

“…Findings from this study can be used to support public authorities and urban planners to effectively design and manage urban spaces to meet dwellers' needs.Visual aesthetic quality (VAQ) is an index to potentially rate USG [9][10][11] and use by decision makers to design and install landscapes that link people and nature [12,13] and best express people's preferences for landscapes. Most VAQ research comes from landscape studies on agriculture [14], architecture [15], and rural forestry applications [16]. Thus, testing the application of VAQ models into UGS provides another land use to explore the application in built environments.Vegetation imparts aesthetics through color, texture, and form [17].…”

Evaluating the Landscape and Ecological Aspects of Urban Planning in Byblos: A Multi-Faceted Approach to Assessing Urban Forests

“…The indexes used are the form mingling index (FMI), which describes the diversity of the form of neighbor trees compared to the reference tree, and the height dominance index (HDI), which is useful for describing the dominance of the height of the reference tree compared to the eight closest neighboring trees. These indexes were calculated based on eight neighboring trees that were the closest to the reference tree, instead of four neighboring trees, due to the long streets and the abundance of trees [31,32].…”

“…On the perceptual testing level, the landscape sceneries were evaluated through visual representation so we could determine the silhouette value of the landscape [32]. Landscape sceneries were shown to volunteers to assess their aesthetic quality.…”