COMPARISON AND EVALUATION OF AIR POLLUTION DISPERSION MODELS AERMOD AND ISCST-3 DURING PRE-MONSOON MONTH OVER RANCHI
Accurate representation of air pollutant dispersion is essential for environmental management and planning purposes. In the present study, two state-of-art air pollution dispersion models, namely AERMOD and ISCST-3 are implemented during the pre-monsoon period of 2010 at Ranchi. AERMOD model is equipped with comprehensive atmospheric boundary layer processes and the other model is based on Gaussian Plume Dispersion concepts only. The purpose of the study is to understand the dispersion of air pollutants such as SO2, NOX and PM10 at Ranchi and additionally the model inter-comparison. The AERMOD model derived boundary layer parameters are validated with the available micro-meteorological tower based in-site measurements and upper air measurements at Ranchi during 1-7 April 2010. The results indicate that boundary layer process which influence the dispersion of the pollutants are better represented in AERMOD model. Spatial distribution of the above-mentioned air pollutants is estimated using AERMOD and ISCST-3 over Ranchi. Dispersion patterns are compared with the windroses. Validation of the concentration distribution of air pollutants of these models are done and found that AERMOD is performing better than ISCST-3. This study advocates that for all air pollution assessment studies it is better to use AERMOD to that of ISCST-3.
RAHUL BOADH, SATYANARAYANA A N V AND RAMA KRISHNA T V B P S