Introduction

In a town like Madison, NJ with mostly residential and business areas, it is important to consider heat severity for the health of residents, vegetation, and all organisms. An ongoing issue in our town is that Madison has plans to increase certain heat severity vulnerability factors by buying the forest on the campus of Drew University and possibly using this land for more residential buildings. This map shows severe heat islands in the Borough of Madison and how tree height relates to them. The lower density and height of trees relates to more heat severity. Compromising the integrity of the dense and tall forest on Drew University would in turn increase severe heat islands in our town.

Data

The heat severity dataset layer of this map was created by The Trust for Public Land. It was calculated using data of recorded thermal readings and using Python coding. Tree height data was collected by Madison ERI by accounting tree density and height throughout the municipal lines. 

Results

The darkest green coloration on this map lies on the campus of Drew University. The most polluted heat severity shown in red and orange primarily roots itself on Main Street of Madison which is the most business district section of the town. When the total borough is broken into properties, 667 of them are at the severe risk level. As temperatures have increased over the years and urbanization continues we can expect an increase in the amount of heat severity. By eliminating forest area, heat severity will spread even further. 

The likelihood of severe heat wave which is defined as 3+ days of the relative severe temperature for a given year has significantly increased over the past 30 years. 30 Years ago it was 23% likelihood of severe heat wave and this year it is 52%. It is expected in 30 years from now this increases to 86%. There are a number of factors that influence this increase, but preserving tree coverage land can lessen the properties that lie in severe heat islands. 

Conclusion

Heat severity is an increasing issue as urbanization evolves. Understanding the natural protection of tree density and height is crucial as land is stripped of its vegetation and industrialized. Forest area typically have an average temperature of 3*F lower than urban areas. Keeping areas with high tree density and height can slow the rate of increased heat severity.

Figure 1: Madison Borough Heat Severity and Tree Height (the darker red/orange indicates area with high temperatures, the green indicates tree height, the darker the green the taller the tree in that area).

About the Data

The layer provided from TPL,  shows heat severity data for every pixel in U.S. cities, using Landsat 8 imagery from 2021. It reveals areas with extreme heat, a leading cause of weather-related deaths, particularly affecting vulnerable populations. The scale rates severity from 1 to 5, aiding cities in planning mitigation strategies. Note, it’s static between yearly updates and doesn’t consider daily fluctuations or air temperature.