Modelling impact of open rice-straw burning emission on ozone air quality in the Bangkok Metropolitan Region | |
| Author | Nguyen Lu Phuong |
| Call Number | AIT Thesis no.EV-06-21 |
| Subject(s) | Ozone Air--Pollution--Thailand--Bangkok Incineration--Thailand--Bangkok |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | In dry weather conditions in the Bangkok Metropolitan Region (BMR), rice straw remained in paddy fields after harvesting is burned. It releases large amounts of air pollution, which may cause serious effects on air quality and public health in BMR and neighboring areas. The aim of this study is to develop the emission database of open rice straw burning in BMR and to preliminarily assess the effects of the burning emission on 03 air quality using the modeling tool. The hotspots which represent rice straw burning activities were counted on the MODIS (Moderate resolution Imaging Spectroradiometer) imagery, which is available 2 times per days for Thailand territory The hot spots were counted for 3 years from January, 2003 to December, 2005 over BMR. The number hot spots counted in a month/day and the total rice plantation areas in BMR were the basis to calculate burned area in the harvested crop season. Emission factors of rice straw burning obtained from the previous studies at AIT were employed to obtain the total emission of ozone precursors in the interested period. The emission further distributed to the gridded BMR domain and time of the day using the information from land-use map and the common burning practice by the farmers in the area. The rice straw emission input data include VOCs (BTX, PAHs and Aldehydes), CO and NOx. An ozone episode occurred in March 24-26, 2004 which corresponds to typical summertime low hot pressure influence over Northern Thailand was selected for simulation. During this episode high levels of 03 were observed over the BMR which exceeded the Thailand National ozone Ambient Air Quality Standard of 100 ppb for a number of hours. A photochemical smog model system, MM5/CAMx, was used for the simulation. The anthropogenic emission data base in 1997 was obtained from Pollution Control Department and the biogenic emissions was determined based on the land use pattern were used in the base case scenario. Impacts of rice straw burning were assessed through 2 cases: the PCD emission database with daily average paddy field burning emission (case 1) and the PCD emission database with daily paddy field burning for the selected episode (case 2). Three statistical measures (Mean Normalized Bias Error), Mean Normalized Gross Error and Unpaired Peak Prediction Accuracy, recommended by USEPA, were used to assess the performance of the model system for the base case, which suggest further improvement of the emission database is required to get better agreement with the monitoring results. When rice straw burning emission was included in case 1 and case 2 there were no significant difference in 03 spatial and temporal distribution as compared to the base scenario except for the Rangsit station (Pathumthani province) which showed higher ozone levels. There was also some inconsistency between the wind direction (both observed and simulated) and direction of 03 plume. Further analysis of pressure fields in the upper atmosphere is necessary to give a more detail explanation of the air mass flow. Effects of boundary conditions were found strong on the East of domain. The simulation should be made with the boundary conditions produced by larger scale models and the domain should be further extended to the East to improve the simulation results |
| Year | 2006 |
| 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 ;Shipin, Oleg ;Vanisa Surapipith |
| Scholarship Donor(s) | Electricity of Vietnam Fellowship ; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2006 |