Water Quality Monitoring Using the Google Earth Engine and Spectral Indices in Wadi Dayqah Dam

Abstract Wadi Dayqah Dam, located approximately 90 kilometres east of Muscat, is Oman’s largest storage facility, with capacity exceeding 100 million cubic metres. The dam was designed to secure freshwater supply, protection from flood events, and provide irrigation demands within the surrounding catchment since 2012. Conventional field-based assessments of reservoir water quality, although authoritative, are labour-intensive, costly and time-consuming. The present study employs a distinctive remote sensing approach, utilizing Google Earth Engine with the Normalised Difference Chlorophyll Index (NDCI), Normalised Difference Turbidity Index (NDTI) and Total Suspended Solids (TSS). Data collected between 2019 and 2024 reveal statistically significant declining trends in Wadi Dayqah’s NDTI, NDCI and TSS. The Findings highlight the methodology’s effectiveness for informed and adaptive management of freshwater resources at Wadi Dayqah Dams, as well as the preservation of downstream ecosystem services. Creating accessible dashboards and visualization platforms enhances public engagement in conservation, enables tracing the sources of pollution, and showcases data-driven insights appeal to a broader spectrum of stakeholders.