Is eThekwini metropolitan municipality (EMM) experiencing light pollution?: A remote sensing analysis of nighttime data of EMM, South Africa

Abstract

Nighttime light remote (NTL) sensing has improved the approaches taken in studying natural and social sciences. NTLs on the Earth surface can be utilised to study huma-related studies such as urbanisation, population, and light pollution. In most cases, NTL application studies are common in fast developing and developed countries such as China and United State of America while African countries are still left behind in taking part in these studies. The study aimed at assessing the effectiveness of NTL data and the extent of light pollution in urban areas of South Africa. This study explores the use of NTL data in studying light pollution in eThekwini Metropolitan Municipality, South Africa. The study quantified and assessed light pollution and its sources in the Municipality using spatial analyst tools such as reclassification and supervised images classification (Maximum likelihood) algorithm. The classes of light pollution were classified ranging from very low to very high light pollution. With land use land cover (LULC) classes representing main sources of light pollution. The study discovered that light pollution is mainly found in and around the city centre of the municipality where main economic and human activities take place. This is where mainly the built-up and commercial LULC classes were observed to be located. The correlation analysis between light pollution and LULC classes revealed strong correlation between high and very high light pollution classes and these LULC classes. These are the areas making use of artificial light at night leading to light pollution in the Municipality.