Analysis of Land Surface Temperature Variations due to Fire at Oil Terminal, Jaipur, India

Thermal pollution, also called heat pollution, occurs when heat released into water or air produces undesirable effects and it can occur as a sudden, acute event that may result from natural events or from human-induced events (Botkin and Keller, 1995). Present study has been carried out in wake of a recent fire catastrophe that occurred at petroleum products storage terminal at Sitapura, Jaipur, India on October 29, 2009. Daily land surface temperature (LST) product of MODIS/Aqua remote sensing satellite has been analyzed to identify zones affected due to the fire event. During the fire event predominant wind direction was NNW/NW and maximum impacted area for thermal pollution was towards SE/SSE direction of the terminal. Area falling within South and East directions of the terminal was divided into 9 directions at an interval of 10o which were further divided into zones based on their distance from the terminal. In order to compare LST values of different dates, LST was normalized using an identified unaffected base area. Normalized mean LST (NLST) values were calculated for all the zones for dates one week prior to the incidence and up to 5 days after the incidence. It was observed that for the week prior to the incidence NLST values for different zones varied up to 50% more than average values, but these values increased to up to 249% after the incidence. Thus maps indicating zones affected by the fire were developed by identifying zones where variations was more than 50%. The study concludes that wind direction has profound effect on thermal pollution of such fire and the thermal pollution was found to be extending beyond 42 km from the place of fire.