Monitoring the Trend of Nighttime Light Pollution (NLP) in the Chattogram District, Bangladesh, Using DMSP/OLS and VIIRS Data

Light pollution affects over two-thirds of the world’s population due to the significant increase in artificial light sources in urban areas. It is an environmental problem that requires attention to ensure a sustainable future. A study was conducted in the Chattogram district, the commercial capital, which is a rapidly growing port city in Bangladesh, to monitor the trend of light pollution over the last 30 years (1992–2021) using nighttime satellite data from the Operational Linescan System (DMSP/OLS) and visible near-infrared (VIIRS). The study applied higher-order multiple regression analysis, using 2012 as the reference year. The results indicated a substantial increase in light pollution, from 9.2% in 1992 to 24.3% in 2021, with most of the increase occurring in the south-west direction. The Chattogram Metropolitan area was the most affected, followed by surrounding regions. A positive correlation was found between built-up spaces and light pollution, which was highly significant in the metropolitan area (R² = 0.508), except for 1993. The study suggests that uncontrolled urban expansion, industrial growth, and excessive port illumination significantly contribute to the rise in light pollution. The report recommends controlling industrial and urban growth and regulating nighttime lighting to address this issue. This research can assist in environmental conservation planning and aid governmental and non-governmental organizations in evaluating light pollution zones and implementing nighttime environmental policies.