AIR QUALITY MODELING: EFFECT OF LAND USE DATABASE USING REMOTE SENSING DATA

AIR QUALITY MODELING: EFFECT OF LAND USE DATABASE USING REMOTE SENSING DATA

In addition to meteorological inputs, land use and emission factor database are also required for simulation of the BiogenicEmission Inventory System (BEIS). The resolution of land use database in the Taiwan BEIS (TBEIS) can be up to 1 km2 and thisdatabase consists of vegetation species and their spatial distribution in Taiwan with a total land area of approx 36000 km2. Theprevious Taiwanese land use database was established in 1995, but since then Taiwan has gone through cultural, ecological andseismic changes for more than a decade. As a result, the area and distribution of current land use types needed revision. To completethis revision accurately, recent satellite remote sensing data were used in this research.In the updated land use database, the new forested area had increased by 2400 km2, grass land had increased by 1790 km2,paddy fields had increased by 2,100 km2 and dry agriculture land had decreased by 1830 km2. There was a net increase of 4460 km2in vegetation area, which equates to about 16% of the total vegetation land area of Taiwan. Simulation of the TBEIS-2 rendered toan increase of 28,000 ton/yr in total BVOCs (6.6%), in which other VOCs (OVOC) increased by 17,000 ton/yr (12.1%) andisoprene increased by 10,000 ton/yr (7.9%). The biogenic emissions obtained by the use of TBEIS-2 with the new land use databaseare utilized to simulate air quality by the Taiwan Air Quality Monitoring (TAQM). Results indicated that concentrations of ozoneand other photochemical pollutants raised in some areas of Taiwan. In the simulation conducted in May 2003, the greatest ozoneconcentration difference occurred in southern Taiwan and central Taiwan with an increase of 3 ~ 7 ppb in these districts.