Short-Term Sentinel-2 Spectral Signature Characterization for Suspended Sediment Assessment in Low-Turbidity Shatt Al-Hilla River, Iraq

Monitoring Suspended Sediment Concentration (SSC) is vital for water resource management, yet traditional methods face logistical challenges. This study evaluates Sentinel-2 imagery's efficiency in monitoring low-turbidity rivers, specifically Shatt Al-Hilla, Iraq. The methodology synchronized in-situ sampling from 30 inspection points (ranging from 8.9 to 20 mg/L) with Sentinel-2 data on February 1, 2026. A comprehensive analysis was conducted using SNAP software to correlate field SSC with the related spectral bands and indices. The analytical and statistical results revealed that a second-degree polynomial model using the red/green ratio and NDTI index provided the strongest statistical correlation, achieving an R² of 95.46% and 94.68% with a low RMSE of 0.51 and 0.56 mg/L, respectively. These results underscore remote sensing's ability to predict the suspended sediment concentrations in the river, distinguish between organic and mineral sediments with the aid of the other indices, and highlight Sentinel-2's effectiveness as a precise, data-driven alternative for monitoring water quality in low-turbidity environments, overcoming the limitations of traditional field-based assessments.