Urbanisation and Urban Heat Island in a Mekong Delta City: From Monitoring to Dominant Factors: Fid-Bau Portal

Urbanisation and Urban Heat Island in a Mekong Delta City: From Monitoring to Dominant Factors

Diem, Phan Kieu / Diem, Nguyen Kieu / Nguyen, Can Trong / Diep, Nguyen Thi Hong

Urbanisation is an indispensable process along with socio-economic development. However, this is also the root of various challenges in urban areas from social to environmental and microclimate changes such as urban heat islands (UHI). This book chapter showcases a case study regarding rapid urbanisation, dynamic of surface urban heat island (SUHI), and controlling factors of UHI in Can Tho city—a regional newly developing city in the Vietnamese Mekong Delta since 2005. Using an integrated methodology framework of earth observation analyses and Analytic Hierarchy Process (AHP), we assessed the urbanisation trends based on urban density and annual growth rate (AGR). The deterioration of SUHI was analysed using land surface temperature (LST) retrieved from Landsat thermal infrared band. AHP is a social approach via expert interviews to identify the key elements and their contribution weights to UHI under the local conditions. It revealed that urban areas have continuously expanded outwards since 2005 towards the Western and main roads along the Bassac river. The AGR is about 0.73%/year over the period of 2005–2019. In particular, the city center has experienced a relatively high rate of urbanisation compared to other areas (i.e., 3.98–5.04% versus 0.5%/year). LST increased significantly and the growth of SUHI was more moderate in terms of intensity and spatial patterns. SUHI is frequently observed in industrial zones and densely populated areas. Urban sprawl was found to significantly stimulate the variations of SUHI intensity. Regarding to the driving factors of UHI, five (05) main factors including nature, society, infrastructure, policy and environment are found contributing to form of UHI at this specific area. In which, the natural factors including coverage ratio of vegetation and water surface are the most contributors to UHI. The key analytical factors from AHP are likely to be prioritised elements, which should be mainstreamed into urban planning to mitigate UHI towards a cooling city.