Contents lists available at ScienceDirect Urban Climate journal homepage: www.elsevier.com/locate/uclim Analyzing trend in artificial light pollution pattern in India using NTL sensor's data Pavan Kumar a , Sufia Rehman a , Haroon Sajjad a , Bismay Ranjan Tripathy b , Meenu Rani c, ⁎ , Sourabh Singh c a Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, India b National Centre for Earth Science Studies, Thiruvananthapuram, Kerala, India c Centre for Land and Water Resource Management, G.B. Pant National Institute of Himalayan Environment & Sustainable Development, Koshi, Uttarakhand, India ARTICLE INFO Keywords: Night time satellite data DMSP-OLS Inter- calibration Light pollution Regression ABSTRACT Exponential growth of population and the resultant rapid rate of urbanization and in- dustrialization in India have significantly transformed its nighttime light environment. The study makes an attempt to analyze the spatio-temporal pattern of light pollution and its causative actors in a fast-developing economy. We utilized nighttime light data from 1993 to 2013 and calibrated through linear regression. Ten patches of major changes from the whole study area were selected to assess the intensity of light pollution at regional scale. Spatial analysis of light pollution in selected patches revealed that New Delhi, Telangana, Maharashtra, Karnataka and Uttar Pradesh experienced increase in very high light pollution intensity. West Bengal, Gujarat and Tamil Nadu witnessed a remarkable change from low to high light pollution. Urban ex- pansion, industrial development and air pollution are main drivers for increasing light pollution. Strong correlation was found between light pollution and digital numbers (DN) values at regional scale. The maps generated through Defense Meteorological Satellite Program Operational Line Scanner Night Time Light data not only helped in assessing the intensity of light pollution but also identified its causative actors.The results of study can effectively be utilized for setting priorities of environmental protection in different geographical regions at various scales. 1. Introduction Large scale urbanization has led to land use modification, built up expansion and increasing concentration of economic activities which has significant impact on inducing environmental problems. Light pollution generally refers to increase in imprudent artificial lightening and resultant changes due to undirected light levels (Lo, 2002). It generally refers to the unprecedent and unobstructed use of artificial lightning. Several scholars have examined light pollution implications on human, plants, wildlife and on other forms of life (Gauthreaux Jr et al., 2006; Longcore and Rich, 2006;Klem Jr, 2007;Polak et al., 2011). Although, this light pollution has severe implications for human health and environment yet nascent scientific attempts for assessing outdoor light pollution are still lacking. The very common effect of light pollution could be visualized in most of the metropolises where the sky looks as though it has been bared of stars leaving behind a vacant haze. Now a days, most of the civilization lives under inter connecting domes of refracted, reflected and scattering rays from over cities, flooded highways and industrial units. Most of the people living in the cities around the https://doi.org/10.1016/j.uclim.2018.12.005 Received 11 January 2018; Received in revised form 3 September 2018; Accepted 12 December 2018 ⁎ Corresponding author. E-mail address: meenurani06@gmail.com (M. Rani). Urban Climate 27 (2019) 272–283 2212-0955/ © 2018 Elsevier B.V. All rights reserved. T