A Procedure for Assessing UHI Intensity in the Central Business District of Accra

Abstract

Aim: The study aims at developing a procedure or method for assessing Urban Heat Island (UHI) in the CBD.
 Study Design: Mobile traverse.
 Place and Duration of Study: The Scott Sutherland School, Robert Gordon University, Garthdee road, Aberdeen, between December 2018 and September 2019.
 Methodology: It entails a review of various UHI types and the methods for measuring them, thereby considering method(s) that would be highly suitable. Weather data measurements are taken by mobile traverse, with a sensor mounted at a level of 1.5 m above the ground. Reference data were recorded at a monitoring point outside Accra. In the study, the dynamics of the UHI intensities within the various local climate zones are analysed. Various analytical approaches are explored for further investigation into the trends in the climatic variations and possible impact of the morphological changes in the urban fabric. 
 Results: Recordings at: Anyaa-NIC, Kwashieman, Jubilee House, Supreme Court, Ministries, National Theatre, Advantage Place, Ridge Hospital and Electoral Commission showed negative deviations between −1 and −2°C from the city’s long-term average temperature. It was noticed that at Advantage Place, which is in open high-rise (LCZ4) development area, the presence of big trees showed lower UHI intensity in comparison with the intensities observed at Jubilee House and Novotel which both belong to the same local climate zone (LCZ).
 Conclusion: This study reveals the presence of UHI in Accra and highlights the importance of using the LCZ classification system. It also highlights the high impact of urbanization on the local climate of the city.