Can you see green? Assessing the visibility of urban forests in cities

Integrated effects of urban morphology on birdsong loudness and visibility of green areas

“…Green areas therefore are significant for quality of life and have high social and economic values (Anderson and Cordell, 1988;De Hollander and Staatsen, 2003;Kirkpatrick et al, 2012). In terms of natural view, green areas have often been studied from the perspectives of visibility (Yang et al, 2009), aesthetics, recreation (Lange et al, 2008), safety and preference (Jorgensen et al, 2002) in urban life.…”

Assessing visual green effects of individual urban trees using airborne Lidar data

“…Establishing regression models of tree green visibility using Lidar-extracted indices Yang et al (2009) proved that specific structural and positional parameters, such as total number of viewable trees/shrubs (NTS) and average height of viewable trees/shrubs normalized by their distances to the photographer (AHT), strongly correlated with Green View. However, no quantitative model has been proposed to estimate tree green visibility using structural variables.…”

“…Therefore, composite variables proposed using "Distance" and other variables were required for better regression models. Yang et al (2009) indicated that such parameters as Average height of viewable trees/shrubs normalized by their distances to the photographer (AHT) were correlated with tree green visibility. Inspired by previous research, several composite variables were designed.…”

“…These studies proved the positive correlation between people's preference towards local landscape design and the presence of greenery. However, most studies to calculate the visual effect of urban trees have been qualitative and subjective (Yang et al, 2009). The widely used research approach for greenery assessment involves the use of photographs and videos.…”

“…Remote sensing images can provide large-scale study with reliable data sources and some landscape metrics are commonly used for landscape pattern analysis. Nevertheless, Yang et al (2009) pointed out that currently used metrics to quantify the structure of urban trees, such as canopy cover (Scott et al, 1998), leaf area index (Xiao et al, 2000), total leaf biomass (Nowak and Crane, 2002), leaf area density (Kenney, 2000), and green plot ratio (Ong, 2003), were not suitable for simulating visual effects of urban trees. Different tree species have a diversity of spatial structures.…”