Urban Heat Islands and Water Quality: A Remote Sensing-Based Literature Review

Urban Heat Island (UHI) is a phenomenon in which urban areas experience a higher temperature than more rural areas along an urbanization gradient. Streams draining urban land can experience higher temperatures due to factors such as increased input of stormwater runoff that has been warmed by hot pavement and lessening vegetation cover, which can have many negative effects on the health of the riparian ecosystem. Research into the UHI effect has increased exponentially in the last 20 years, particularly using geospatial technology and satellite observations. The objective of this review is to analyze the current literature on the UHI effect and understand its impact on water quality of urban waterways by synthesizing all the published articles emphasizing the use of remote sensing technology. Articles were synthesized and categorized to understand the data and satellite imagery used (sensor types), research methodology, geographical distribution, and primary research questions. Many studies emphasized the role of water bodies as a heat sink in urban environments and how blue infrastructure can be implemented to mitigate harm or discomfort to humans due to the heat island, but literature exploring the impact of this usage on the riparian ecosystem is sparse. This review aims to offer a data-backed view of this knowledge gap and explore opportunities for future research on this topic.