Spectral Reflectance Curves of Waste at Landfill Sites in Vietnam

Abstract

With increasing amounts of waste being generated in developing countries, landfill capacity shortages are becoming apparent. As a result, there are concerns that the number of open dumping sites managing waste poorly and disposing of waste inappropriately will increase. These sites are not generally government-authorized, and their gas emissions and leachates are not managed at all. Moreover, identifying the locations of open dumping sites is not simple. In this study, we calculated spectral reflectances and recorded spectral reflectance curves of waste, soil, vegetation and leachate from measurements with a portable spectral radiometer in central and southern Vietnam, at landfill sites in Hue and Nha Trang. Even though waste in landfill and dumping sites is heterogeneous, being mixtures of various materials including plastic, paper and food waste, we confirmed that the spectral reflectance curves of waste presented in this study have consistent regularity regardless of measurement point and field of measurement; the spectral reflectance of waste gradually increases from 10% to 40% as the wavelength goes from 350 nm to 850 nm. The results suggest that using satellite data to develop techniques for identifying locations of open dumping sites will be worthwhile and signify that reflectance curves of waste obtained by on-site measurements will be useful as ground-truth data. The study also revealed that spectral reflectance curves of waste are similar to those of soil as the next challenge in detecting the locations of open dumping sites via satellite data.