Utilizing Remotely Sensed Observations to Estimate the Urban Heat Island Effect at a Local Scale: Case Study of a University Campus

Abstract

The urban heat island (UHI) effect has become a significant focus of research in today’s era of climate change, and a key consideration for the next generation of urban planning focused on green and livable cities. UHI has traditionally been measured using in situ data and ground-based measurements. However, with the increased availability of satellite-based thermal observations of the Earth, remotely sensed observations are increasingly being utilized to estimate surface urban heat island (SUHI), using land surface temperature (LST) as a critical indicator, due to its spatial coverage. In this study, we estimated LST based on Landsat-8 observations to demonstrate the relationship between LST and the characteristics of the land use and land cover on the campus of King Abdulaziz University (KAU), Jeddah, Saudi Arabia. We found a consistent variation of between 7 and 9 degrees Celsius for LST across campus, spanning all summer and winter seasons between 2014 and 2019. The LST correlates strongly with both green vegetation and built-up land cover, with a slightly stronger correlation with the latter. The relationship between LST and green vegetation has a notable seasonality, with higher correlation in the summer seasons compared to the winter seasons. Our study also found an overall increase in LST between 2014 and 2019, due to intentional changes in the built-up land cover, for example from the conversion of natural green surfaces to artificial surfaces. The findings of this study highlight the utility of the remotely sensed observation of LST to assess the SUHI phenomenon and can be used to inform future planning aimed at securing green and livable urban areas in the face of a changing climate.

Remotely Sensed Derived Land Surface Temperature (LST) as a Proxy for Air Temperature and Thermal Comfort at a Small Geographical Scale

“…Similarly, the impacts of the composition of different types of land cover on SUHI have been examined in the cases of Austin and San Antonio, Texas [48] and Portland, Oregon [49]. Recently, [50] estimated patterns of LST over King Abdulaziz University campus (Jeddah, Saudi Arabia), demonstrating the potential of Landsat-derived LST estimates to map long-term changes of the UHI phenomenon at a geographical scale of a university campus.…”

“…We estimate LST using Landsat-8 observations and compare LST's derived spatial patterns against in situ climatological measurements and thermal comfort. The objectives of this study are as follows: (1) to validate the methodology presented in [50] to map the extent and spatial patterns of LST in the case study of KAU campus and the surrounding residential neighborhoods; (2) to evaluate the relationship between LST and climatological in situ measurements; (3) to evaluate the association between T air , LST and PET (as an indicator of thermal comfort); (4) to evaluate the relation of T air , LST and PET to LULC; (5) to demonstrate the impact of different types of land cover and land use on micro-climate variations.…”

“…Similar to [50], we converted the raw reflectance value in Band 10 (B10) of each scene into a TOA spectral radiance (radiance measured by the sensor). We extracted the radiance "multiplicative" and the radiance "add" rescaling factors from the metadata of each scene using this expression: TOA (L) = (ML * DN) + AL.…”

Role of Urban Greening Strategies for Environmental Sustainability—A Review and Assessment in the Context of Saudi Arabian Megacities

“…For example, Jeddah has grown beyond the capacity of its infrastructure. Other cities, including Riyadh and Dammam, have also experienced significant growth in the urban population over the last few decades [34,66]. In developed countries, the roles of GSs have been well documented due to their contribution to urban environmental sustainability and the well-being of urban dwellers.…”

A Proposed Planning Concept for Public Open Space Provision in Saudi Arabia: A Study of Three Saudi Cities

“…A larger open space will provide positive experiences to a wide variety of users [ 25 ], including children, adults, and older people [ 26 ]. Furthermore, larger open spaces play an important role in cities by fostering biodiversity [ 27 ] and mitigating high temperatures [ 28 ].…”