Products · Water
Surface Water and Wetland Monitoring
Four decades of water extent for any lake, wetland or reservoir, with a six-month outlook.
Self-service platform in the ARASAT Hub
Overview
How much water is in this wetland today, how has it changed since 1984, and where is it heading?
A satellite platform that measures open-water extent for wetlands, lakes, reservoirs and dams on every satellite pass, reconstructs the record back to 1984 from harmonised Landsat and Sentinel-2 archives, adds radar, vegetation, water-quality and climate context layers, and forecasts water-surface area up to six months ahead. Delivered as a multi-tenant web application for any area of interest in the world.
- 1984 to present
- Archive depth
- 6 months, 14-day steps
- Forecast horizon
- 8 indices, temperature, ET, soil moisture, terrain
- Context layers
- Any area of interest worldwide
- Coverage
System architecture
Schematic of the main components, from inputs to delivered outputs.
Inputs
- Landsat 5–9 archive
- Sentinel-2
- Sentinel-1 radar
- MODIS, reanalysis and climate data
- User areas of interest
Processing
- Optical water detection
- Radar water detection
- Cloud and shadow masking
- Spectral indices and thermal layers
Analytics
- Water-area time series
- Radar–optical calibration
- Six-month forecast with intervals
Outputs
- Interactive 2D and 3D maps
- Reports, CSV and GeoTIFF
- REST API
- Team and quota management
How it works
Pipeline and maturity of each stage
- 01
Area-of-interest selection
OperationalPredefined regions or user-uploaded polygons in common GIS formats, with metadata-only discovery of optical and radar acquisition dates and per-scene cloud cover.
- 02
Optical water extent
OperationalA single surface-reflectance rule applied identically to Sentinel-2 and harmonised Landsat 5, 7, 8 and 9 produces one consistent water series from 1984 to the present, with cloud and shadow masking.
- 03
Radar water extent
OperationalSentinel-1 backscatter with incidence-angle normalisation, speckle filtering, dual thresholds for open water and wet surfaces, and per-region calibration against clear optical scenes, so water is mapped through cloud and at night.
- 04
Context layers
OperationalEight spectral indices including chlorophyll and algal-bloom indicators, land-surface temperature, evapotranspiration, soil moisture and a 30 m elevation model, served as map tiles.
- 05
Time series and history
OperationalProgressive back-fill of monthly water area for every year since 1984, in hectares and as a percentage of the region, charted and exportable.
- 06
Six-month forecast
OperationalA gradient-boosted model trained across all monitored regions predicts water area in 14-day steps up to six months ahead, validated chronologically against a seasonal baseline and delivered with prediction intervals.
- 07
Maps, reports and exports
OperationalInteractive 2D and 3D viewer with swipe comparison, measurement and pixel inspection; cloud-optimised tiles; PDF reports, map images, CSV and GeoTIFF downloads.
- 08
Accounts, teams and quotas
OperationalMulti-tenant access with plans, team members, per-region processing allowances and an administrator view, behind a documented REST API.
Data used
- Sentinel-1 GRD
- Sentinel-2 surface reflectance
- Landsat 5, 7, 8 and 9
- Landsat thermal
- MODIS evapotranspiration
- ERA5-Land soil moisture
- SRTM 30 m DEM
- Gridded climate data
Methods and models
- Harmonised optical water index rule
- SAR thresholding with angle normalisation and speckle filtering
- Radar–optical threshold calibration
- Spectral indices
- Gradient-boosted multi-horizon forecasting
- Cloud-optimised GeoTIFF tiling
Outputs
- Water extent maps per acquisition, optical and radar
- Water area time series, 1984 to present
- Six-month water-area forecast with confidence band
- Index, temperature, evapotranspiration, soil-moisture and terrain layers
- PDF reports, CSV, GeoTIFF and map exports
Who it is for
- Environmental agencies and wetland conservation
- Water authorities and reservoir operators
- Researchers and NGOs
- Drought and water-security monitoring
More in Water
All water products- Water quality indicatorsHub platform
- Evaporation and water budgetProcessing service
- Soil moistureHub platform
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