Creating an Interactive Urban Tree Map of Gibraltar

Abstract

The environmental benefits from urban forests on urban populations, has grown substantially due to the rise of pollution levels within urban areas. Digital mapping of trees has become another measure by Governments and city planners to assess, reduce and mitigate the carbon footprint of urban areas. Gibraltar’s tightly built up old town, contains an active urban forest of wild and landscaped tree planted areas, creating micro-habitats for wildlife and contributing to its urban environment. Despite this, there has been only partial data collected and mapping of Gibraltar’s urban trees, without any assessment of the environmental benefits that each tree provides, individually and collectively.

This study combines different methodologies to create an interactive web-based urban tree map. Individual urban tree characteristics data were collected, using the following tree data collecting equipment, standards and methods: photographing each tree; measuring each tree’s diameter at breast height (DBH); and calculating tree heights using LiDAR data. The i-Tree software application was used to analyse each tree’s environmental benefits. Collected data was stored within Oracle’s high-performance relational database management system. The Python module, Folium, was applied to create the interactive web-based mapping application, using the JavaScript library, Leaflet. Lastly, an online survey was created via SurveyMonkey, to gather user-feedback on the web-map’s usability. This case-study is intended to provide a useful guide to those wanting to develop effective interactive web-based mapping applications for urban forestry, to determine its environmental benefits.