By Sarang Pramode | 3/14/23
How Important Are Trees? Really?
Urban trees are essential to the sustainability and livability of our cities. They provide numerous benefits to both residents and the environment, making them an important aspect of city planning and design. However, accurately measuring and analyzing the impact of urban trees can be a challenging task.
Have you ever wondered how much tree coverage your city has? Have you ever tried to quantify the impact of those trees on your community? Well let me tell you, it’s no simple task.
First of all, measuring tree coverage can be tricky. Sure, you could go out with a pair of binoculars and try to count every leaf, but that’s not exactly practical. Plus, you might miss some trees hiding behind buildings or blending in with other vegetation. And even if you do manage to get an accurate tree count, what does that even mean? How do you quantify the impact of those trees on the environment or the community?
But there’s hope! Thanks to new technologies like LiDAR, we can now create detailed 3D models of the urban canopy and quantify the impact of trees in a more accurate and efficient way. But even with these new tools, it’s not a simple task.
LiDAR, or Light Detection and Ranging, is a remote sensing method that uses laser pulses to measure the distance to an object and create a 3D point cloud. This technology has the potential to revolutionize our understanding of urban trees, providing a detailed and accurate view of the tree canopy in our cities.
Quantifying The Urban Canopy with TerraVide
New York City seeks to produce a digital simulation of each street tree in NYC and quantify its local shading benefits, study the distribution of these benefits in the city, and develop tools to inform more equitable and effective future tree planting strategies.
The ability to classify and quantify tree shading is essential for making equitable tree planting decisions and reducing the urban heat island effect. Urban heat islands are caused by the concentration of heat-absorbing surfaces such as pavement and buildings, which can lead to higher temperatures in urban areas. Trees provide shade and cool the air, helping to counteract the urban heat island effect. You can view a map of temperature variations in the city here
In this series of articles, we present the capabilities of TerraVide, which is a package to process LiDAR data and assess local shading impact of trees. We have built a toolkit to classify unstructured point cloud data obtained from LiDAR scans conducted by city governments. We have implemented TerraVide as part of TreeFolio version 2 which is a collaboration between The Design Across Scales Lab at Cornell AAP and the Urban Tech Hub at Cornell Tech. The toolkit uses unsupervised learning techniques to label vegetation, ground, and building points in an unlabeled dataset and provides useful information for making equitable tree planting decisions and analyzing the impact of trees as infrastructure in a neighborhood. By using 3D coordinates in the state plane, the toolkit is able to discreetly identify trees in the dataset and quantify usable tree shade over various times of the year. It has been optimized for high CPU performance and can efficiently utilize hardware with a large number of compute resources, making it ideal for applications that require computationally intensive tasks and can classify a large area quickly with high accuracy. The results can be used to provide classification labels to raw LiDAR point clouds and extract valuable shading metrics and tree characteristics to reduce urban heat islands.
Check out our articles on medium for a walkthrough of our process – Read More
Advised by Dr. Anthony Townsend (Urbanist in Residence, Urban Tech Hub)