This layer shows the mean water turbidity over the selected period, computed as the Normalized Difference Turbidity Index (NDTI) from ESA/Copernicus Sentinel-2 Surface Reflectance imagery (COPERNICUS/S2_SR_HARMONIZED) at 10 m native resolution. NDTI is the normalized difference between the red (B4) and green (B3) bands and is computed only over water pixels, with clouds and shadows masked. Higher values indicate more turbid water (more suspended particles); lower values indicate clearer water.
The layer maps the mean water turbidity over the selected period using the Normalized Difference Turbidity Index (NDTI) derived from Sentinel-2 optical imagery. Each Sentinel-2 scene in the interval is masked to retain only water pixels (Scene Classification Layer class 6), with clouds, cloud shadows and defective pixels removed. NDTI is then averaged pixel by pixel across the period to produce the annual mean composite.
| Code | Provider | Resolution | Year |
|---|---|---|---|
| WRD_S2XXX_99 | ESA/Copernicus | 10 m | selected period |
Method: NDTI = (B4 − B3) / (B4 + B3), where B4 is the red band (665 nm) and B3 the green band (560 nm); the index is computed per scene on water pixels and the temporal mean over the selected date range is returned. Reference: Lacaux et al. (2007), Remote Sensing of Environment, 106, 66-74.