Spatio-temporal analysis of the relationship between urban heat island and air pollution concentration using satellited data and ground-based monitoring station | |
| Author | Nontawat Thongdee |
| Call Number | AIT Thesis no.EV-26-15 |
| Subject(s) | Urban heat island Air--Pollution--Data processing Air quality monitoring stations |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Rapid urbanization in Bangkok has intensified the Surface Urban Heat Island (SUHI) effect while compounding air quality challenges across its 50 districts, yet the spatio-temporal coupling between these two phenomena remains poorly characterized. This study integrates daytime Land Surface Temperature (LST) derived from Landsat 8/9 thermal infrared imagery with nighttime LST from the MODIS MOD11A2 product, downscaled from 1 km to 100 m via a Random Forest regression model, and ground-level concentrations of PM2.5, PM10, NO2, CO, and O3 from Pollution Control Department and Bangkok Metropolitan Administration monitoring stations for the period 2020 – 2024; ground records were quality controlled through station completeness screening, z-score outlier removal, and Inverse Distance Weighting gap-filling before Pearson and Spearman correlation analyses were applied to quantify UHI–pollutant associations by season and diurnal period. Daytime results reveal a consistent land zone thermal hierarchy in which dense urban and bare/paved surfaces reached 44 – 46°C in summer, water bodies provided the strongest cooling effect (SUHI ≈ −5°C relative to the agricultural fringe) but thermally inverted at night to become the warmest zone (nighttime SUHI peaking at +2.4°C) due to high thermal inertia, and the dense urban core sustained daytime SUHI of +3.2°C in summer and +5.6°C during the monsoon, the latter amplified by enhanced evapotranspiration cooling in peripheral vegetated areas. Correlation analysis identified CO as having the strongest positive daytime association with SUHI (r = +0.82), while PM2.5 and PM10 were negatively correlated with daytime LST (r = −0.35 and −0.38, respectively), reflecting aerosol-induced solar attenuation; NO2 showed significant positive correlations with both LST and NDVI (r = +0.49), consistent with its photochemical coupling to O3 production, and inter-annual trends confirmed a marked rebound of combustion-derived pollutants from 2022 onward following the lifting of COVID-19 mobility restrictions. These findings collectively demonstrate that UHI and air pollution in Bangkok are intimately coupled across seasonal and diurnal timescales, providing empirical grounding for heat-resilient and low-emission urban development strategies such as expanding connected water bodies and green corridors for daytime cooling and implementing district-level emission controls during the dry season. |
| Year | 2026 |
| Type | Thesis |
| School | Faculty of Civil and Environmental Engineering (2026) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EEM) |
| Chairperson(s) | Ekbordin Winijkul |
| Examination Committee(s) | Xue, Wenchao; |
| Scholarship Donor(s) | Royal Thai Government Fellowship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2026 |
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