Numerical study on regional climate change due to the rapid urbanization of greater Ho Chi Minh City's metropolitan area over the past 20 years

Abstract

This study examines climatic impact of urbanization on the variability of the urban heat island (UHI) effect over Greater Ho Chi Minh City metropolitan area (GHCM), since the late 1980s, using the dynamical downscaling with very high‐resolution regional climate model coupled to an urban canopy model (RCM/UCM). This is the first application of RCM/UCM to a city in developing countries in Southeast Asia in assessing the impacts of the past land‐use and anthropogenic heat release during the selected three periods (ca. 1989, 1999, and 2009). The main findings are as follows: First, agreement between simulated results (for case of ca. 2009 urban) and observation demonstrates that the RCM/UCM is able to reproduce the urban climate of GHCM. Second, the evolution of spatial distribution of UHI is closely associated with urban expansion. The increase in the surface air temperature was about 0.3 °C in the pre‐existing urbanized area and about 0.6 °C in newly urbanized area in the last 20 years. Main factor of these changes is conversion of agriculture or grassland into urban structure, which results in increase in sensible heating and decrease in latent heating. In addition, in the central GHCM, the urbanization impact was estimated at 0.31 °C, while the temperature increase was observed at 0.64 °C in the last 20 years. This suggests that the urbanization may contribute about half to the increase of surface air temperature in the central GHCM.

Characteristics of climate change and its relationship with land use/cover change in Yunnan Province, China

“…Because local urbanization was proved to have remarkable effects on regional climate change (e.g. Chen et al , ; Grawe et al , ; Doan and Kusaka, ), such close correlations between temperature and the NDVI at these two stations might be associated with their developments of urbanization. In contrast, the CC values between the NDVI and precipitation varied from −0.245 ( p > 0.1) to 0.221 ( p > 0.1), and none of the correlations was statistically significant (Figure ).…”

“…Because local urbanization was proved to have remarkable effects on regional climate change (e.g. Chen et al, 2011;Grawe et al, 2013;Doan and Kusaka, 2016), such close correlations between temperature and the NDVI at these two stations might be associated with their *The trend at the significance level of p = 0.05. **The trend at the significance level of p = 0.01. developments of urbanization.…”

Impact of future urbanization on temperature and thermal comfort index in a developing tropical city: Ho Chi Minh City

“…Two simulations based upon the current urban (CU) and future urban (FU) were conducted. Due to the rapid urbanization that could considerably change the urban land use in GHCM within even few years (Doan and Kusaka, 2015), the long-term, e.g. ten years, simulation with one certain CU is likely unrealistic in representing real climate of the region.…”

“…The region's total population has grown from 11.2 million in 1989 to 17.3 million in 2009. Rapid urbanization has induced regional climate change, especially the increase of UHI over urban areas (Tran et al, 2006;Luong, 2008aLuong, , 2008bDoan and Kusaka, 2015).…”

Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City

“…Meteorological data were used to evaluate the performance of the dynamic downscaled model, and the result of this validation is presented elsewhere. 15 …”