The long-term trends of PM10, O3 and NOx concentrations were analyzed using Holland model (without meteorological-adjusted) and MM-Regression model (with meteorological-adjusted) based on the data of ten EPA air quality stations from 1997 to 2006 in Kao-Ping area. The aim of this study was to determine the impact of meteorological factors on the trends of these pollutants in Kao-Ping. The annual variations (AV) of O3 was −0.496 % in Kaohsiung county, −0.200 in Pingtung county, and 0.277 % in Kaohsiung city, showing different characteristics in Kao-Pin area. On average, the annual variations (AV) influenced by meteorological factors were: PM10: 0.205 %, O3: −0.127 %, and NOx: 0.338 %. After being adjusted by meteorological factors, the seasonal variations (SV) were about 1, indicating little seasonal change. In Kao-Ping region, the influence by meteorological factors was 9.566 %, 8.026 % and 7.351 % in PM10, O3, NOx, respectively. In total, the average influence was 8.314% in Kao-Ping region, with 7.791% in Kaohsiung city (8.481% at Cianjin, the most influenced area), 9.439% in Kaohsiung County (10.368% at Linyuan, the most influenced area), and 7.110% in Pingtung County (7.516% at Chaojhou, the most influenced area). PM10 was influenced most by meteorological factors (PM10: 9.566 %, O3: 8.026 %, NOx: 7.351 %) in Kao-Ping area.. In Kao-Ping region, the contributions by individual meteorological factors were 70.78% in wind speed, 38.23% in total cloudiness, 36.56% in sunshine hour, 19.86% in temperature, 12.40% in atmospheric pressure, 5.96% in relative humidity and 1.27% in wind direction. The influences by the wind speed were 66.62 %, 72.35 % and 72.31 % on the concentrations of PM10, O3, NOx, respectively. Wind speed was the most important factor controlling concentration trends in Kao-Ping area.

The trends of PM10, O3, NOX and NMHC concentrations were analyzed by the Holland model (without meteorological-adjusted) and the MM-Regression model (with meteorological-adjusted) base on the data of eight EPA air quality stations from 1997 to 2006 in Kaohsiung. The aim of this study was to evaluate the influence of meteorological factors on the pollutants (PM10 and O3) trends. The trends of PM10 concentrations in Kaohsiung city analyzed without meteorological-adjusted were 7.18 % at Tzuo-Yin, 3.20 % at Chien-Chin and 9.72 % at Nan-Chie. After eliminating the meteorological factors, the percent of gradual trends were 1.91 % at Tzuo-Yin, 2.92 % at Chien-Chin and 2.02 % at Nan-Chie. The trends of O3 concentrations without meteorological-adjusted were 11.42 % at Tzuo-Yin, 20.92 % at Hsiung-Kong, 42.08 % at Chien-Chin and 13.69 % at Nan-Chie. The trends of PM10 concentrations in Kaohsiung County analyzed without meteorological-adjusted were 14.96 % at Lin-yuan and 3.24 % at Jen-wu. After meteorological factors eliminating, the trend was 3.15 % at Jen-wu but the trend was -2.53 % at Lin-yuan. Meteorological factor was a primary reason that influences the PM10 concentration in recent years. The trends of O3 in Kaohsiung County without meteorological-adjusted were 18.89 % at Da-liao, 4.40 % at Jen-wu, 35.16 % at Lin-yuan and 29.98 % at Mei-nung. After meteorological factors eliminating, the trends were 1.99 % at Da-liao, 2.23 % at Jen-wu, 1.16 % at Lin-yuan and -1.16 % at Mei-nung. The results show that the influence of meteorological factors for O3 trends was more sensitive in Kaohsiung county than in Kaohsiung city. The concentration of PM10 has no significant difference (64.8 ¡V 92.3 %) in Kaohsiung city. For the concentration of O3, the similarity (78 ¡V 100 %) was extensive in Kaohsiung city because O3 could diffuse easily. O3 episodes has no significant difference as PM10 episodes in Kaohsiung city. As above-mentioned, the results show that the contributions of ambient PM10 were individually but the contributions of ambient O3 were uniform extensively.