Our Urban Forest StoryMap: How we Tell the Complete Story of our Tree Canopy

By NYC Parks Deputy Chief of Data Systems & Analytics Uma Bhandaram

WHAT IS THIS STORY AND WHY ARE WE TELLING IT?

Have you ever looked out your window and wondered about the trees you see? How has the tree canopy cover changed over time? Who takes care of these trees? What does the forest look like in another part of the City?

As Parkies, we are tremendously proud of the work we do to steward NYC’s urban forest. And as the Data Systems & Analytics team for the Environment and Planning division, we are data geeks and passionate about telling stories via numbers, maps, and other visualizations. When we realized that there was no one place on the internet that showcases the story of NYC Parks’ stewardship, management, and maintenance of the City’s trees, we set out to combine our two loves — trees and data — by creating “Our Urban Forest” StoryMap.

Though the public can find tree-related datasets on NYC’s Open Data Portal, telling a story using these datasets requires work. You would have to know where to look and what to do with the data once you found it. You would have to go through several steps to combine, relate, and visualize the data. This would require you to download data, relate tables by using unique identifiers, import into geographic information system software, visualize the data, and perform analysis.

We chose, instead, to tell the story ourselves and improve transparency and engagement between Parks and the public. By creating the “Our Urban Forest” StoryMap, we hope to educate and communicate about the importance of NYC’s urban forest and tree services provided by NYC Parks

This story represents a huge milestone — the first time that there is one location where the public can learn about NYC Parks trees — why they are important, where they grow, how they change over time, how they are cared for, and how the public can get involved.

This story is meant to be inspirational as much as it educational. We hope you will feel empowered to use the information and linked sources to connect with and advocate for the trees in your backyard, park, and across the City.

WHY DID WE CHOOSE ArcGIS StoryMap?

We weaved multiple different datasets on street trees, park trees, existing canopy, canopy change over time, and tree services. This is a complex story and cannot be adequately told through static maps, charts, etc. We needed a platform that would allow us to share maps, data, and other multimedia content in a narrative and dynamic way that would also be user-friendly. We wanted to share analytical information, illustrate spatial relationships, and provide data visualizations. And finally, we wanted to present the data in a way that users can contextualize and use to compare current state and changes across geographies and jurisdictions.

We chose ArcGIS StoryMaps for their ability to do all of this and more. StoryMaps are an effective and engaging way to tell a story in a digital format. And, their ability to host interactive content, link to external sources, configure pop-ups, and be shared publicly made it the perfect choice for our needs. Using StoryMaps allowed us to build a tool that is a one-stop shop for all things urban forest in NYC by linking to related resources, reports, tools, and other organizations working in the same space.

HOW DID WE TELL THE STORY?

Six of nine sections of the story are used to summarize data regarding trees, canopy, and tree services. Data is summarized at different scales — borough, council district, community board, neighborhood, and census tract. The tree canopy data is also summarized by jurisdiction — how much falls either on parkland and City right-of-way (ROW) or other lands.

For each summary in these sections, we created individual web maps on ArcGIS Online and inserted in the story. And for each web map, we created customized pop-ups that include comparative analysis. In total, we created 80+ web maps! We developed a custom-built basemap comprised of 20+ layers, each with unique symbology and levels of visibility, to provide an enhanced sense of place. To ensure optimal performance, we used ArcPro 2.0 to create a tile package and published to AGOL as a tile map. This caches all the images and ensures fast visualization.

In each web map, the user can see canopy polygons as they zoom in closer. The canopy polygon dataset is very large and is comprised almost 6 million rows! Using this data led to slow performance. To support faster drawing, we used the geoprocessing tool ‘Simplify Polygon’ to reduce the number of vertices which reduces file size and allows for faster rendering.

In the “Tree Canopy Change” section, a slider widget can be used to pan over aerial imagery and learn where there has been growth, loss, or no change in canopy between 2010–2017.

We maximized every functionality available to us to share analytics. In the tree services section, we wanted to provide data that is aggregated and summarized by geographies but also broken down by types, i.e., what types of Service Requests comprise the total received by this neighborhood? To do so, we configured the pop-up elements to have charts where users can see all of these stats.

HOW WILL WE UPDATE THE DATA?

Tree services data is from fiscal years 2021 and 2022. We will add data as each fiscal year ends so that users can compare data temporally as well as geographically. As new data becomes available, we will also update our analysis on tree canopy and change.

To continue adding data while retaining a user-friendly interface, we’ve decided to use StoryMaps collections when adding data in the future. Collections will allow us to group stories together and navigate cohesively. We will take each section of the current tool and turn it into its own story. As we get ready to add more data to Collection, it will get added as its own story.