Location Analysis of Potential Planting Space for Urban Forests in Austin, TX

Summary
    The U.S. Census Bureau has named the Austin area one of the fastest growing metropolitan areas in America, growing in population by almost 30% from 2010 to 2019 (U.S. Census Bureau, 2020). As Austin continues growing, its ecological footprint will also grow with it, presenting its city planners and policymakers with an opportunity to work towards lowering both the city's carbon emissions and its urban heat island score, while also ensuring environmental equity to all of its residents. One way to efficiently address all three of these issues is to increase the amount of urban forests within the city. Tree Planting Location Services (TPLS) was commissioned by Alan Halter and the City of Austin Urban Forestry Program to update the existing community tree priority areas map by finding all of the available space within Austin's city limits that could be used for planting new trees as of 2021. TPLS conducted this research by using GIS to remove the currently existing canopy, impervious cover, surface water, and other areas that cannot be used for planting, leaving behind only the areas that could potentially be used for tree planting.

Purpose
  The resulting map will be used in conjunction with demographic data and urban heat island scores associated with each census tract in Austin to help city planners and policymakers understand which parts of Austin are of highest priority for planting new trees. This map will contribute to Austin's Urban Forest Plan released in 2013, and eventually it will be used to help to alleviate some of the environmental injustice happening in Austin while also lowering both carbon emissions and urban heat island scores around the city.

Methods
  The data that we needed to complete this project was given to us by the client, and it included all of the impervious cover, existing canopy, surface water, and other unplantable areas in Austin. We started by transforming the layers into vectors, and then clipping the layers to our study area, which was the full watershed regulation area of Austin. Next, we merged all the unplantable data together and ran the less than tool to find only the plantable space. The output was not exactly what we needed as it still had the surface water as part of the plantable space, so we used raster calculator, set null, and reclassify to remove the surface water. This gave us a layer with only the pervious areas that could possibly be planted with new trees.

Conclusion
    Our final product was a map that showed all of the potential planting space within Austin. We also made a few other maps that show the urban heat island scores of each census tract in Austin, and the distribution of people living in poverty and people of color (POC) in each census tract so that they can be compared to the potential planting space map. The areas with high urban heat island scores, high numbers of POC and people living in poverty that also overlap with areas that have a lot of potential planting space should be made top priority for planting new trees. Our results show that East Austin is of highest priority for planting new urban forests due to the lack of trees currently in that area as well as the high number of people living in poverty and people of color living in that same area. Our final map of possible planting space will help guide city planners as they strive to make Austin a better place for all.