Monitoring artificial light pollution in Iran

Light pollution is generally referred to as an unplanned increase in artificial lighting and the result is a change in light levels. Population growth and the rapid expansion of urbanization and industrialization can be a factor in increasing light pollution in Iran. Therefore, monitoring night light changes and determining areas with high light pollution is essential and can provide a new approach for environmental planners to use it to manage light pollution at the national and provincial levels. There are several tools for evaluating changes in night light, including operational linear satellite scanning data related to the Meteorological Defense Satellite Program (DMSP / OLS). These data not only help assess the severity of light pollution, but can also be used as a tool for pollution risk management and risk zoning. This study tries to analyze the spatial-temporal pattern of artificial light and light pollution in Iran between 1996 and 2013 by processing DMSP / OLS data and detects critical sources of light pollution. Night light data were used in six time periods (1996, 2001, 2004, 2006, 2011 and2013).  The changes in night light and the intensity of light pollution on a national scale evaluated. Besides the relationship between the relative population density changes in each province and its effect on the changes in night light were analyzed in this research. The results show an increase in night light as well as conversion of low-brightness areas with high-brightness areas during study periods across the country. In addition, the provinces of Tehran and Alborz were identified as the provinces with the highest levels of light pollution in the country, and followed by Khuzestan, Isfahan, Bushehr and Fars. Increasing relative density and unbalanced distribution of population, migration and its intensification between 1996 and 2011 are the main factors in the increase light pollution in the country and also the concentration of maximum light pollution in some provinces.