Authors: Michelle Dornath-Mohr*, University of Alabama in Huntsville, Leiqiu Hu, University of Alabama in Huntsville
Topics: Remote Sensing, Rural Geography, Urban Geography
Keywords: UHI, rural biome, cultivation, landcover, vegetation, anthropogenic modification
Session Type: Paper
Presentation File: No File Uploaded
Urban heat islands (UHI) are widely documented, anthropogenically induced modifications of regional climate, whose magnitude is defined as the difference between the urban temperature and a rural reference temperature. Current literature typically treats varied rural areas as equal representatives of the rural reference temperature when determining UHI magnitude. However, ignoring the effects of anthropogenic modification of the rural biome can cause a biased estimate of UHI magnitude. In this paper we assess the influence of anthropogenic activities in rural biomes on UHI magnitude. Using the Chicago UHI as a case study, we use multi-year land surface temperature data (LST) over a typical growing season (April – October) to examine the response of LST to natural and cultivated landcovers. Our results show that agriculture activities, when compared with natural vegetation, alter daytime LST throughout the growing season. Landcovers with natural vegetation such as forests and wetlands generally provide cooler reference temperatures than cultivated crops. The major difference we found is that before emergence and maturation of crops the LST is higher over cultivated areas than over urban areas while naturally vegetated areas have lower LST than urban areas. However, following crop maturation both cultivated areas and natural vegetation are cooler than urban areas. We also observe that annual temperature variations due to natural events, such as heat waves and droughts, affect the overall UHI signature. This better understanding of temperature variation across the rural biome will provide insight about the true signal of human-induced temperature changes and improve global UHI studies.