Sediment transportation index for coastal and port areas
A screening measure of where sediment is likely to move, settle or build up.
The sediment transportation index combines satellite observations of suspended sediment with wave and current data to show how sediment moves through coastal waters. It points to areas prone to siltation, scour and shoreline change. It supports early planning for ports, channels and coastal works.
Turbidity, waves, currents and tides
From open coast to a single harbour
Relative, not absolute, transport
Based on archive imagery
What is a sediment transportation index?
Sediment moves when waves and currents supply enough energy to lift grains and carry them. Fine sediment travels in suspension and clouds the water, which satellites can see as higher reflectance in the red and near-infrared bands. Coarser sand moves close to the bed and is inferred from wave and current strength.
An index brings these ideas together in a simple relative score. Satellite turbidity is converted to an estimate of suspended sediment concentration, then combined with modelled current speed and direction and wave energy. High values mark pathways and source areas, low values mark places where sediment tends to settle.
Over many seasons, the pattern shows sediment plumes from rivers and dredging, longshore drift along a beach, and accumulation in channels and basins.
The index is a screening tool. It does not give a tonnage per year, and satellites see only the surface layer. Quantified transport needs field sampling, current profiling and a calibrated numerical model. We use the index to focus those studies where they matter most.
How it works
Observe
Derive suspended sediment patterns from satellite imagery over many dates.
Combine
Add wave, current and tide data for the same period.
Compute
Calculate the relative index across the area.
Interpret
Identify source, pathway and deposition zones.
What you receive
Maps
a. Sediment index map
b. Turbidity maps by season
c. Transport direction indicators
Interpretation
a. Hotspots of siltation and scour
b. Recommendations for field validation
Where it is used
Port siltationPredict where basins and berths will fill with sediment.
Dredging planningFind sediment sources and plan disposal sites.
Intakes and outfallsCheck for sediment risk near cooling water intakes.
Coastal structuresUnderstand sand movement around breakwaters and groynes.
Reef and seagrass protectionTrack plumes that reduce light and smother habitat.
Beach managementLink erosion patterns to sediment supply and drift.
Frequently asked questions
Is this a measurement of sediment volume?
No. It is a relative index that shows where transport is stronger or weaker. Volumes need field data and a calibrated model.
Can satellites see sediment at depth?
No. They see the surface layer of the water column, so the index reflects suspended sediment near the surface and relies on models for the rest.
How does it relate to beach erosion history?
Erosion history shows where the shoreline moved. The sediment index helps explain why, by showing where material is going.
Does it work in clear water?
It is most informative in waters with measurable turbidity. In very clear water there is little suspended signal to track.
Where is sediment going near your site?
Tell us about the port, channel or coastline and we will outline a sediment screening study.
