Analysis of the Surface Urban Heat Island in Chicopee, Massachusetts,using Landsat-8 Analysis Ready Thermal Imagery
Honors Thesis
Rachel Corcoran-Adams
Department of Geography
Rachel Corcoran-Adams
Department of Geography
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Date: May 2019
Background: The Massachusetts Department of Conservation and Recreation (DCR) Greening the Gateway Cities Program (GGCP) is a UGP designed to increase tree canopy cover in environmental justice neighborhoods and thus, to reduce household utility costs for renter populations. This paper examines the association between urban tree canopy and its impact on, and future potential for, SUHI mitigation in the city of Chicopee. In order to examine the association between SUHI and locations occupied by marginalized communities, the paper also examines if SUHI hotspots, defined as locations of consistently high LST, are predominantly located in environmental justice zones within Chicopee. Summer-season Analysis Ready Landsat-8 thermal data (ARD) (2019) were used to identify trends in LST at pixel, block and neighborhood scales. |
Tree cover in Chicopee, MA (a) and within the Department of Conservation and Recreation planting zone (b)
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Data:
Source |
Date |
Spatial Resolution |
Temporal Resolution |
Use in Analysis |
DCR Chicopee Urban Forest Inventory |
2015-present |
N/A |
N/A |
Trend detection |
U.S. Landsat ARD |
June 14, 2019 |
30m |
16-day |
Trend detection |
MassGIS Environmental Justice Zones |
2010 |
N/A |
N/A |
Trend detection |
DCR Chicopee Planting Zone Trees Planted |
2015 |
N/A |
N/A |
Trend detection |
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Methods:
Statistics Analysis Minimum, maximum, and median LST values were extracted for each Environmental Justice zone. Environmental Justice zone 1 represents the census block with Minority and Income isolation, zone 2 represents areas with the highest concentration of low-income residents, zone 3 represents the area with highest concentration of minority, low-income, and English isolated residents, and lastly, zone 4 represents the area with the highest concentration of minority residents. The Chicopee Memorial State Park and Westover Airport were used as control sites. Chicopee Memorial State Park is a dense forest and the Westover Airport has a large area of concentrated impervious surface (Figure 4). In order to extract temperature values from these control areas, polygons were created around each area and the minimum, maximum and median values were extracted. Tree cover and LST Comparison In order to answer the question of whether or not urban tree cover planted through the GGCP in 2015 has mitigated the SUHI effect in Chicopee after 3-4 years, LST values were extracted from a planted area and an unplanted area. LST values in the locations with denser tree cover were cooler and locations with less forest cover were hotter were inputted into a spreadsheet. The planted location was chosen as an area with dense urban tree cover planted by the GGCP in a residential neighborhood. The unplanted location was chosen as a residential area lacking urban tree cover but similar in landscape as the planted location. This area also was chosen as a location with extensive impervious cover. A box-plot displaying the two locations was created in order to compare the LST values in both areas. Outcome: Sites within close proximity to impervious surfaces and with low tree canopy had higher LST values (e.g. 56.25 degrees Celsius), and areas with dense canopy cover had lower LST values (e.g. 34.8 degrees Celsius. Neighborhoods in a planted area tended to have lower LST values than neighborhoods that were not planted in (e.g. 19-degree Celsius difference in LST). This is likely due to homogenous local land-cover and canopy shading from DCR-planted trees. Furthermore, locations with increased building cover were more likely to have less canopy cover, thus leading to high LST values in surrounding neighborhoods. |
Box plot of Land Surface Temperature Values in a non-tree planted area versus a tree planted area of the Department of Conservation and Recreation planting zone
Zonal Land Surface Temperature (LST) statistics for Department of Conservation and Recreation Planting Zone
Zonal Land Surface Temperature (LST) statistics for Chicopee, Massachusetts
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I will be presenting this research at the American Association of Geographers' Meeting in 2021.