Remote Sensing of Turbidity Patterns in Warri Coastal Waters

Turbidity is a critical optical parameter of coastal waters that influences light penetration, primary productivity, sediment transport, and the suitability of aquatic habitat for marine organisms. This study employs remote sensing techniques to map and monitor turbidity patterns in the coastal waters adjacent to Warri, Delta State, South South Nigeria, an area subject to intense petroleum industry activities, dredging, and urban runoff. Sentinel-2 multispectral imagery from 2021 to 2024 is processed to derive surface reflectance values in the red and near-infrared spectral bands, from which turbidity indices are computed using established empirical algorithms calibrated with in-situ nephelometric turbidity unit measurements. Spatial and temporal patterns in turbidity are analysed in relation to seasonal rainfall, dredging activity logs, and tidal phase data. Cloud-free image composites are produced for both dry and wet seasons to characterise seasonal variability. Field validation cruises are conducted concurrently with satellite overpasses to evaluate algorithm performance. Results are expected to demonstrate elevated turbidity near refinery outfalls and dredging corridors, with significant seasonal amplification during the rainy season. Long-term trend analysis reveals progressive turbidity increase over the study period. Findings are communicated to the Warri Port Authority and the Delta State Environmental Sanitation Authority to support evidence-based intervention planning. Keywords: turbidity remote sensing, Warri coastal waters, Sentinel-2, Delta State, water clarity monitoring