Spatial and Temporal Variations of Nitrogen Dioxide and Ozone Concentrations Assesment Using A Gis Based Geostatistical Approach in Balikesir, Turkey

Abstract

Urban air pollution are sourced manily from traffic, industry, and heating systems. Rapidly increasing population, unplanned urbanization and industrialization are the main contributors to urban air pollution in many countries. Nitrogen dioxide (NO2) and ozone (O-3) are the main pollutants that are formed from traffic, combustion related activities and photochemical smog processess. These pollutants have capable of causing adverse effects on human health and environment. Since NO2 is a typically traffic related pollutant emissions are generally highest in urban atmosphere rather than rural areas. Ground-level and tropospheric ozone is one of the most harmful air pollutants causing health problems, premature deaths, reduced agricultural crop yields, changes in ecosystem species composition and damage to physical infrastructure and cultural. In this study, we have used a combination of passive sampling and GIS techniques to characterise the intra-urban scale and rural temporal-spatial distribution of air quality based on NO2 and O-3 concentrations. The aim of this study is of locate sample points, characterize distribution patterns, perform the probability map, and map distributions of NO2 and O-3, by means of spatial information sciences providing useful information for decision-makers. Firstly, the data were compiled from 48 sampling sites by using passive sampling on10-17 March 2010 in winter and on 13-20 August 2010 in summer. Later, estimated pollutants levels at un-sampled locations were carried out with the Inverse Distance Weighted (IDW) method. Finally, location exceed the Turkish Air Quality Standard critical threshold value were determined in the Balikesir city area by use of geostatistical algorithms (Indicator kriging). The results of the passive sampling study show that the winter and summer average concentrations are 28.85 mu g/m(3) and 111.26 mu g/m(3) for O3; 22.65 and 13.56 mu g/m(3) for NO2 respectively. It is expected that where industrial activity is not excessively important, traffic and domestic heating system are the main source of NO2 and O-3 precursors. Moreover, results show that there are multiple hotspots for NO2 concentration and they are strongly correlated to the locations of traffic and domestic heating system in the Balikesir city area, using Indicator kriging (IK). Clearly close to roads, the major source of pollutants such as NO2, the concentrations of pollutants will be highest. In addition to emissions, meteorology plays a strong role in both the general and in the local meteorological environments. O-3 concentrations are higher in summer than in winter season, given the same traffic volume, due to the local meteorological parameters such as solar radiation, wind circulation. It was demonstrated that geostatistical tools are quite appropriate techniques for air quality management in a polluted city area like Balikesir.