Selection of interpolation technique for spatial distribution of prominent pollutant in a traffic induced polluted area

Urbanisation has led to an increase in air pollution by the addition of various pollutants from industrial emissions, automobile exhaust, etc. Air quality index gives an indication of quality of the ambient air. By identifying the prominent pollutant, the control strategies to reduce its emission can be taken. The prominent pollutant was identified by comparing the sub-index of pollutants in the area. A spatial distribution map of the prominent air pollutant concentration was prepared in GIS using five interpolation techniques - Universal Kriging, Ordinary Kriging, inverse distance weighting, spline regularised and spline tension. The selection of best technique is crucial as it determines the accuracy to which the spatial distribution of the pollutant is modelled. In this study, the prominent pollutant of the study area was found to be PM10. Ordinary Kriging and inverse distance weighing were identified as the best methods for mapping of PM10 concentration in Thiruvananthapuram corporation.