APPLICATION OF CALINE 4 MODEL TO PREDICT PM2.5 CONCENTRATION IN MEGACITY DELHI

Abstract

The current trends in urban development, including growth of road transport, increasing energy demand and rising house hold consumption causes severe damage to urban environment, health and quality of life in cities. Rapid increase of the vehicle population in mega cities has results in the poor environmental quality and human health. Ambient concentrations of air pollutants at major traffic intersections are exceeding the National Ambient Air Quality Standards (NAAQS) in Delhi. The people are exposed to higher pollution levels which causes health problems i.e. respiratory diseases. Hence, an attempt was made using CALINE 4 model to estimate fine particulate matter (PM2.5) concentrations at roadways of Madhuban chowk, Janpat, Punjabi Bagh, Karol Bagh, Uttam nagar, Laxmi nagar in Delhi. Traffic analysis of roadways was conducted on hourly basis and traffic volume is found in units of vol./hr. Peak flows of traffic were recorded between 10:00AM to 12.00 Noon at Madhuban Chowk, 11:00 AM to 13.00 Noon at Janpat, 11:00 AM to 13.00 Noon and 17:00 eve to 19.00 eve at Punjabi Bagh, 16:00 noon to 17.00 Eve at Karol Bagh 15:00 noon to 17.00 eve at Uttam Nagar, 17:00 eve to 19.00 eve at Laxmi nagar. Concentraton of PM2.5 is measured for every minute time interval. Measured PM2.5 with EPAM HAZ-5000 was ranged from 889 μg/m3 to 399 μg/m3 at Madhuban Chowk, 842 μg/m3 to 102 μg/m3 at Janpat, 267 μg/m3 to 7 μg/m3 at Punjabi Bagh, 410 μg/m3 to 21 μg/m3 at Karol Bagh, 520 μg/m3 to 11 μg/m3 at Uttam Nagar, 514 μg/m3 to 25 μg/m3 at Laxmi Nagar. Hourly average measured PM2.5 ranged between 680 μg/m3 to 432 μg/m3 at Madhuban Chowk, 372 μg/m3 to 150 μg/m3 at Janpat, 142 μg/m3 to 26 μg/m3 at Punjabi Bagh, 111 μg/m3 to 57 μg/m3 at Karol Bagh, 217 μg/m3 to 38 μg/m3 at Uttam Nagar, 173 μg/m3 to 81 μg/m3 at Laxmi Nagar. Estimated PM2.5 concentrations using CALINE 4 hourly average ranged from from 680.8 μg/m3 to 432.7 μg/m3 at Madhuban Chowk, 379.4 μg/m3 to 155.4 μg/m3 at Janpat, 170.8 μg/m3 to 41.3 μg/m3 at Punjabi Bagh, 120.7 μg/m3 to 61.4 μg/m3 at Karol Bagh, 226.6 μg/m3 to 42.7 μg/m3 at Uttam Nagar, 192.1 μg/m3 to 82.2 μg/m3 at Laxmi Nagar. Maximum concentrations were observed in evening time than in morning or afternoon time. The estimated concentrations of PM2.5were compared with measured concentrations of PM2.5.The eight hourly average of observed and predicted values are 625 μg/m3 and 625.8 μg/m3 at Madhuban Chowk, 254.44 μg/m3 and 264.48 μg/m3 at Janpat, 90.11 μg/m3 and 114.56 μg/m3 at Punjabi Bagh, 91.37 μg/m3 and 98.63 μg/m3 at Karol bagh, 86.67 μg/m3 and 92.72 μg/m3 at Uttam Nagar, 124.44 μg/m3 and 131.37 μg/m3 at Laxmi Nagar. The comparison is done using Normalized Mean Square Error (NMSE), Fractional Bias (FB), and Geometric Mean Bias (GMB) and the results of NMSE, FB and GMB were found to be within prescribed limits as NMSE value is less than 0.50, FB value is from -0.5 to +0.5, and GMB varies between 0.75 to 1.25. Hence, CALINE 4 model is a useful tool to estimate the particulate matter concentrations near roadways in the city like Delhi.