Urban Heat Island associated with Land Use/Land Cover and climate variations in Melbourne, Australia

• Published in: Sustainable cities and society 2021-06, Vol.69, p.102861, Article 102861
• Main Authors: Mohammad Harmay, Nurul Syahira, Kim, Daeun, Choi, Minha
• Format: Article
• Language: English
• Subjects: Australia; Climate change; Community Land Model; Land Use/Land Cover; Urban Heat Island
• ISSN: 2210-6707; 2210-6715
• DOI: 10.1016/j.scs.2021.102861

•When the urban and built-up area increased by +14.93 % in 2014, UHI intensity (ΔT) increased by ∼1.20 ± 0.20 °C.•The LCI of urban and built-up area was higher in 2014 compared to 2001.•UHI altered the surface energy balance resulted in higher Qh and lower Qle.•UHI was driven by convection reduction, surface evaporative cooling, and heat storage release during multiple hydroclimatic events.•The UHI component attributions were also linked with precipitation and background temperature in Melbourne. Urbanization is known as one of the most prominent global problems that alter the atmosphere and land surface properties. The intensity of Urban Heat Island (UHI) associated with surface temperature and component attributes were assessed using the Community Land Model (CLM). The variations of UHI with Land Use/Land Cover (LULC) and climate variations were also investigated to provide a link among urbanization, surface energy balance interactions, and extreme hydroclimatic events which are drought (‘big dry’ and ‘angry summer’) and heavy rainfall (‘big wet’) in Melbourne, Australia. Generally, UHI demonstrated a uniform increasing trend with an ∼1.20 ± 0.20 °C increment, along with urbanization expansion of +14.93 % from 2001 to 2014. Furthermore, urban area showed positive contribution to UHI based on Land Contribution Index (LCI). High surface temperatures also resulted in higher sensible heat flux (Qh) and lower latent heat flux (Qle). During the multiple extreme climate events, the UHI biophysical drivers were majorly related to the convection reduction during ‘big dry’ (2001−2009), surface evaporative cooling during ‘big wet’ (2010−2011), and heat storage release during ‘angry summer’ (2012–2013). Overall, this analysis demonstrated correlation of UHI intensity and its component attributes with urban expansion, which was associated with LULC and climate variations in Melbourne.