Performance evaluation of air pollution models for Delhi City

Abstract

In a rapidly developing country like India, the transport sector is growing rapidly and number of vehicles on Indian roads has increased from 0.3 million in 1951 to 37.2 million in 1997, ie, an increase of almost 124 times. This has led to overcrowded roads and a polluted environment. Total tonnes of emission per day in Delhi in terms of carbon monoxide, hydrocarbons, nitrogen oxides and suspended particulate matter ranges from 9,992 in 1986 to 27 800 in 2001. To predict the concentration of vehicular pollutants, various models have been developed and the most popular among them are the CALINE models and Finite Line Source models (GFLSM). However, the suitability of these models for Indian conditions needs to be thoroughly investigated before they are applied for prediction of pollutant concentration under Indian scenario. In this paper, various air quality models are reviewed to evaluate the performance of CALINE 4 and General Finite Line Source model in terms of carbon monoxide prediction. Eight selected locations in Delhi are identified for study. Prediction of carbon monoxide concentration is done for all the eight selected locations using both the models. The predicted concentration of carbon monoxide through CALINE- 4 ranges from a minimum value of 2415 ?g/m3 to a maximum value of 7015 ?g/m3 while through GFLSM it ranges from 2067 ?g/m 3 to 6033 ?g/m3 respectively. The comparison between predicted and observed concentration is done usingstatistical methods like regression analysis, significancetest and index of agreement to evaluate model performance.