UTILISING VIIRS DNB NIGHTTIME LIGHT DATA TOGETHER WITH LANDSAT DAYTIME DATA TO ASSESS CHANGES IN LIGHT POLLUTION IN ETHEKWINI METROPOLITAN MUNICIPALITY (EMM)
- 1Department of Geography, Faculty of Natural and Agricultural Science, University of the Free State, Bloemfontein, South Africa
- 2Department of Geography, Faculty of Natural and Agricultural Science, University of the Free State, Phuthaditjhaba, South Africa
Keywords: Light pollution, NTL data, Night-time imagery, artificial light, VIIRS DNB, urban area
Abstract. Night-time light (NTL) data has become widely used in different studies, including urbanization and light pollution subjects. Some sources of NTL data have made the data freely available on online platforms, making it easy to study subjects that relate to the use of artificial light at night. African countries have not published much on the use of NTL data. Still, there has been a development in different countries in the continent, such as economic growth and the provision of new and improved infrastructure. These developments can be considered primary contributors to the increase in light pollution worldwide. This study aimed at using NTL data together with familiar daytime data to assess how light pollution has been changing in eThekwini Metropolitan Municipality and again assess the changes in the sources of light pollution through the assessment of Land-use Land-cover (LULC) change of the study area. NTL images were reclassified into five different classes of light pollution using the reclassification tool in ArcMap 10.7. Supervised classification was performed to assess the changes in LULC. The confusion/error matrix was done to verify the accuracy of these classifications. These showed that light pollution is increasing in eThekwini Metropolitan Municipality, with the increased built-up area also being witnessed. NTL data is becoming useful worldwide, and it is highly recommended for African countries also to do research using this data in their studies.