Sampling site
The sampling site was located at the meteorological station in
the area of Mae Hia Research Center, Chiang Mai University, Muang
District, Chiang Mai Province, Thailand. This station was located at
98 550 54.300 E and 18 450 40.300 N. Its elevation was 334 m above
sea level. The sampling site has been classified by the Acid
Deposition Monitoring Network in East Asia (2000) criteria as
a rural site, ever since the year 2000. However, due to the rapid rate of development of the city of Chiang Mai over the past 10 years, this
study site should therefore be classified as a sub-urban area. The
land use profile of the sampling site is shown in Fig. 1. The impor-
tant sources of anthropogenic emissions around the sampling sites
are Chiang Mai International Airport (3 km east), various specific
tourist attractions (the Night Safari and the Royal Gardens) (2.5 km
southwest), Chiang Mai City (6 km northeast) and an industrial
estate (25 km southeast).