1. Introduction
According to Article 6, Paragraphs 2 and 3 of the Air Pollution Control Act, those newly added or modified stationary pollution sources within Class 2 and Class 3 of air pollution prevention regions in which air pollutant emissions quantities reach a certain regulatory scale is required to perform modeling and simulation for their pollutant emissions quantities in order to verify that these quantities will not exceed allowable increment limits of air pollutant concentrations. As Article 8, Paragraph 2 stands, within a total quantity control zone that meets air quality standards, those newly installed or modified stationary pollution sources for which pollutant emissions quantities reach a certain scale is required to perform modeling and simulation for their pollutant emissions quantities in order to verify that these quantities will not exceed allowable increment limits within the zone. The scientific and technical knowledge and information that the development and application of air quality models need to accomplish their missions spread in all kinds of academic and advisory organizations, which result into the decentralization of resources, duplicate constructions, various qualities, and barriers of information. Taiwan Air Quality Modeling Center (TAQMC) actually is a policy and technique supporting organization with a combination of experts and data resources in the industry, the government and the academics. The tasks accomplished and relative productions are shown as follows according to the sequence of objectives for this year in the project plan.
2. Objectives for this year in the project plan
(1) Cooperate in the application and examination of air quality models to be approved.
(2) Assist the Environmental Protection Bureaus (EPB) of counties and cities in technical examinations and consultations of air quality modeling.
(3) Update and pronounce the relative data for the simulations of allowable increment limits of air pollution concentrations.
(4) Assess the benefits of air quality modeling related laws on the air quality improvement
(5) Maintain and update the TAQMC website and consultation service
(6) Evaluate the influence of new development programs on air quality using air quality models
(7) Analyze the feasibility of the application of the AERMOD model system in Taiwan
3. Execution results
The tasks accomplished in this project are shown as follows according to the sequence of objectives in the plan.
(1) Cooperate in the application and examination of air quality models to be approved
(a) The required documents and database for the application of models to be approved were approximately established, and published by the governing organization. Some database were updated this year and continuously maintained and examined. These data can be downloaded from the website.
(b) Until the end of December, 2009, EPA was assisted to review 51 environment impact assessment cases concerning air quality modeling.
(2) Assist the EPB of counties and cities in the technical examinations and consultations of air quality modeling
(a) The raw data during 2006-2007 in local governments, industrial bureau, and scientific industry park management bureau were reviewed to find out the implementation status of “allowable increment limits” strategy and give suggestions for amelioration. This year 59 cases were selected, among which 54 cases provided complete data and 4 cases from the same company were combined into one case. Therefore altogether 51 cases were reviewed.
(b) This project conducted three air quality model workshops: in the north region on November 19, in the central region on November 17, and in the south region on November 13. The total 78 participants include the executors in EPB of local governments, environmental engineering in advisory companies, and the academic researchers.
(3) Update and pronounce the relative data for the simulations regarding allowable increment limits
(a) With primary principle analysis, seven episodes were selected, including 2/8-2/17、4/10-4/19、4/30-5/4、5/7-5/11、9/12-9/16、10/22-10/26、12/11-12/15. The trajectories of O3 and PM10 emission sources were simulated using Gaussian Trajectory transfer-coefficient modeling system (GTx). Some power plants in Taiwan were selected as the emission sources of forward trajectory modeling to show the pollution area. The monitoring stations of EPA in seven air basins were selected as receptors in backward trajectory modeling. Some episodes for O3 and PM10 were suggested as official cases in priority sequence after analysis and discussion.
(b) NCEP/AVN global meteorological grid database of the six months in 2007 were established; besides, the meteorological fields were simulated for February, April, May, September, October, and December in 2007, as the initial conditions for air quality modeling. Moreover, the simulated meteorological parameters in all the selected episodes in 2007 were analyzed and evaluated with the observations.
(4) Assess the benefits of air quality modeling related laws on the air quality improvement.
(a) The basic structures of the laws related to air pollutant modeling and allowable increment limits in Taiwan are generally similar with those in the USA, including applicable areas, principles for input data to models, principles for the parameters in models and allowable increment limits.
(b) In reference to the questions on the air quality simulation related laws, our project consulted experts, researchers, environmental agencies, and advisory companies, and held forums to collect the opinions and suggestions on the laws. The rules of laws that should be modified include “air pollution prevention regions in municipalities, counties, and cities”, “Allowable increment limits of air pollutant concentrations” and “Simulation guidance for air quality models”.
(c) Based on the 85% control ratio of total emission quantity for NO2 corresponding to an regulatory emission scale of 40 ton/year, it is suggested that the regulatory emission scale of TSP should be adjusted from 15 to 3.5 ton/year, and that of SO2 from 60 to 15 ton/year, and that of NMHC from 30 to 10 ton/year.
(d) Based on the 75% control ratio of total emission quantity for the hourly average NO2 with the allowable increment limit as 8 ppb in the third restriction area, it is suggested that the allowable increment limit of yearly average NO2 should be adjusted from 2 to 0.3 ppb, and that of daily average TSP from 63 to 3.0 g/m3, and that of yearly average SO2 from 1 to 0.2 ppb, and that of daily average SO2 from 3 to 1.2 ppb, and that of hourly average SO2 from 8 to 5 ppb. Also, the allowable increment limit of PM10 should be added with the yearly average number as 0.5 g/m3 and hourly average number as 2.0 g/m3.
(5) Maintain and update the website of TAQMC and consultation service
(a) The TAQMC website provides not only the documents to read and download, but also advisory and discussion of questions on air quality models. Meanwhile, online data search and incorporate sources are also available. It provides adequate data and technical support for the local government and the staff in advisory companies. The main task this year is to update the website and maintain the functions.
(6) Evaluate the influence of new development programs on air quality by air quality models
(a) Our project accomplished the “Review guidelines on the offset of incremental air pollutant emissions in environmental impact assessment of new development program (draft version)”.
(b) The ratio of PSI > 100 in Taiwan and central air basin were collected and ozone indicators were calculated. With the emission inventory and meteorological data in 2007, four scenarios in the central air basin in 2011 and 2016 were simulated to calculate the allowable emission capabilities of NOx and VOCs.
(c) The environmental impact of Changpin Industrial Park was analyzed in two episodes during May 7-11 and from April 30 to May 4 in 2007.
(7) Analyze the feasibility of the application of AERMOD model system in Taiwan
(a) Our project inspected whether or not there is enough data to support the utilization of AERMOD and relative preprocessing sub-models in Taiwan, modified the codes before the meteorological simulations of AERMET to use in Taiwan, examined the compatibility of guidelines on Gaussian model and AERMOD, and wrote the substitute codes for AERMAP, as well as the first complicate terrain calculation in Taiwan.
