Reflectance spectroscopy using visible and near-infrared (vis-NIR) spectra can help classify and map soils based on their weathering and formation processes. By analyzing soil samples and profiles, researchers found that vis-NIR spectral data can distinguish soil types based on their physical, chemical, and mineral properties. They used Principal Component Analysis and clustering algorithms to group soil samples and profiles according to their weathering levels and formation processes. The study showed that vis-NIR reflectance spectroscopy is a valuable tool for soil survey and classification, allowing for the identification of different soil classes and variations in clay and iron oxide content within soil profiles.