The Chiangmai haze episode in March 2007 : cause investigation and exposure assessment | |
| Author | Ketsiri Leelasakultum |
| Call Number | AIT Thesis no.EV-09-09 |
| Subject(s) | Haze--Evaluation--Thailand--Chiang Mai Air--Pollution--Evaluation--Thailand--Chiang Mai Agricultural wastes--Environmental aspects--Thailand--Chiang Mai |
| Note | A thesis submitted in partial fulfillment of requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | In March 2007, there was a severe air pollution episode in Chiang Mai province, thus this study attempts to determine the main causes of the haze episode. Seasonal variations of emission sources (traffic, industries and biomass burning) were examined. The classification of meteorology governing over the northern region of Thailand during February-April was done by a newly developed scheme. The main emission source of the episode was biomass burning that included forest fire and agriculture residue burning. The most polluted pattern during haze episode period is pattern 2, characterized by hot low pressure cells covering the northern part of Thailand whereas a ridge covering the Eastern sea of China; clear sky, light wind, low mixing height and low humidity. This type of synoptic meteorology brings about subsidence and radiative inversion. Results from analysis of hotspots, synoptic patterns and backward trajectory for each day in March 2007 confirms that main causes of haze episodes are increasing of hotspot counts (both in local and upwind region) associated with the condition of pattern 2. The stepwise regression was performed to develop prediction models of PM10 for synoptic pattern 2. The regression equations have the coefficient of determination (R2) of 89 % with reasonable agreement between the predicted and observed PM10 levels. Therefore, the proposed forecasting procedure is recommended for warning system for Chiang Mai haze episode. Exposure risk assessment of the Chiang Mai community during March 2007 was done using a combined approach of ground based PM10 monitoring, satellite AOT data and GIS tools. The highest risk was observed on March 13, when the wind was mostly calm to weak and the prevalent wind direction was Westerly Southwest wind (WSW). Forest fire at upwind region was the main emission source which brought to high exposure risk areas on Central part of province. Thus, specific health care planning for this area should be planned for future haze episode. |
| Year | 2009 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Nguyen, Thi Kim Oanh; |
| Examination Committee(s) | Chongrak Polprasert;Thammarat Koottatep; |
| Scholarship Donor(s) | RTG Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2009 |