Assessment and Modeling of Light Pollution in Al-Kut City Using RS and GIS

Abstract

Artificial lighting is often viewed as a symbol of modernity and one of civilization's greatest achievements. In fact, the level of development in some parts of the world is sometimes measured based on satellite imagery taken at night. However, nighttime lighting, once used sparingly, is now being misused due to advancements in light sources, both in production and operation. Poorly designed or excessively bright light sources have harmed the natural environment and human health. This impact is not limited to cities; it also extends to remote protected areas illuminated by artificial light diffused into the atmosphere. Furthermore, the overall harmful effect of artificial lighting on the natural environment is called light pollution, which is classified into two types: astronomical light pollution, which affects the quality of astronomical observations, and environmental light pollution, which affects the natural environment. This distinction is reflected in scientific research and studies, which typically fall into one of these two categories.

Light pollution is one of the fastest growing types of environmental pollution, and its levels have increased significantly compared to natural nighttime lighting levels. Given the absence of local laws or regulations governing lighting or reducing light pollution in Iraq, this research aims to assess the state of light pollution and its environmental effects in the city of Kut. By modeling sky brightness using updraft radiation measured from artificial sources by global platforms, along with field monitoring of light intensity values, the research relied on the optical analysis of platforms specializing in monitoring and tracking light pollution, namely (dark site finder, light pollution map (Light trends), Radiance Light Trend, World Atlas 2015 of Light Pollution, lightpollutionmap.app), which extend data from 2012-2026. These platforms revealed high light intensity values ​​in the center of Al-Kut city, and it was classified as a very light city within the category (<18.38 mag/arcsec2) for the Sky Quality Measurement (SQM) and category (9) for the Portl Light Pollution Scale, due to the excessive use of white light (LED), especially in commercial areas and traffic intersections. To verify the visual analysis of these platforms, (35) locations in the city of Kut were selected for field monitoring of light pollution levels. This also revealed a significant increase in artificial brightness values ​​in the study area. The highest light pollution value was recorded in Al-Hawra neighborhood, reaching (1288 LUX), as it is one of the commercial centers in the city of Kut. The intensive use of white light, in addition to street lighting, was reflected in the high light intensity values. The lowest light pollution value was recorded on the outer road (Kut-Hay), reaching (37 LUX). Light pollution values ​​in other locations varied significantly both spatially and temporally, depending on the urban neighborhoods and their land uses. This was demonstrated by RS technology through the Google Earth Engine platform and the analysis of DMSP-OLS nighttime lighting data for the period (2010-2025). To further this, ArcGIS 10.7 technology was employed to represent light pollution values ​​in the city of Kut using the Inverse Distance Weighing (IDW) method, which showed Nighttime lighting varies in intensity and range depending on land use within the city.

Therefore, the study recommends developing awareness strategies and programs to raise awareness of the dangers of light pollution from both an economic and environmental perspective. It also recommends reducing the use of LED and blue light panels, using only essential lighting, directing lights downwards, covering lamps to reduce nighttime sky brightness, and using low-pressure yellow sodium lamps to minimize light pollution and lower energy consumption.