Automated Surface Water Body Extraction Using the Normalized Difference Water Index (NDWI) with an Interactive Thresholding Interface

Abstract The effective management and continuous monitoring of surface water resources are fundamental to environmental sustainability, climate science, and socio-economic stability. Remote sensing, powered by satellite technology, offers a powerful, scalable, and cost-effective methodology for mapping and monitoring the dynamics of water bodies over vast spatial and temporal scales. This paper presents a detailed computational methodology for the automated extraction of surface water from high-resolution multispectral satellite imagery, with a specific focus on data acquired by the Operational Land Imager (OLI) sensor aboard the Landsat 8 and 9 satellites.