AIR POLLUTION FEATURES OF THE VALLEY-BASED TOWNS IN HUNGARY
Z. UTASI, J. MIKA,A. RÁZSI
ABSTRACT.- Air Pollution Features of the Valley-Based Towns in Hungary. There are 30 valley-based towns with >10,000 inhabitants in Hungary, filled by 1.023 million people i.e. 10 % of the population. Two criteria are used to define the valley-based town. They are: (i) Vertical difference between the lowest point in the town and the highest one around it should be >100 m. At the same time, (ii) the same difference on the opposite side should be >50 m. Air pollution data by the National Air Pollution Observation Network are used. Five contaminants were selected and analysed for 2007, 2010 and 2013. Due to a sharp reduction in the network, we could find data for a small part of the valley-based towns. Control towns with equal air-quality observations and similar cumulative number of inhabitants were also selected. The contaminants and the number of the settlements are: NO2 manual (14 valley-based vs. 2x14 control), NO2 automatic (8 vs. 8), SO2 automatic (7 vs. 2x6), PM10 automatic (8 vs. 2x7) and PM10 deposition manual (6 vs. 8). Average values, as well as high concentration episodes (>98%thresholds) are equally analysed and evaluated. The main conclusion is that there are so big differences between the years both in absolute values and relative sequence of valley-based and control groups that the analysed there years is not enough to make any final conclusion. For step-over frequencies, however valley-based towns have some advantage, possibly due to the valley-hill wind system.
Keywords: urban air-pollution, valley-circulation, NO2, SO2, PM10, Hungary.