Child pages
  • Product Sheet: Surface Soil Moisture

Surface Soil Moisture (SSM) & Soil Water Index (SWI)


Decadal soil Water Index based Dryness Index at 2nd decade July 2014 (Source: GeoVille/TU Vienna)




Component products

Land Cover


  • N/A



  • Environmental monitoring – Natural Hazard Risk Analysis
  • Logistics planning and operations – Facility siting, pipeline routing and roads development
  • Logistics planning and operations – Support to surveying crews for planning surveys and H&S

Geo-information requirements

  • Detailed land cover information
  • Terrain information
  • Lithology, geology and structural properties of the near surface


This product provides surface soil water information based on a decadal (10-day average) Index data derived from radar imagery. The Surface Soil Moisture indicator represents the degree of saturation of the topmost soil layer (< 5 cm) and is given in percent, ranging from 0% (dry) to 100% (wet). The Soil Water Index represents the soil moisture content in the first 1 meter of the soil in relative units ranging between wilting level (0) to field capacity (100). The algorithm uses an infiltration model describing the relation between surface soil moisture and profile soil moisture as a function of time.

The products are based on a time series of ERS-1 & ERS-2 radar data from 1992-2006 and MetOp ASCAT radar data from 2007-present. Future continuation is ensured by Sentinel-1.

Soil moisture is crucial for all biological life on land and influences the energy, water and carbon fluxes at the land surface. Further, it influences hydrological and agricultural processes, runoff generation, drought development and impacts on the climate system. Thus, soil moisture is a crucial parameter for a large number of applications including flood prediction and identification of wet areas.

This product delivers PDF maps or raster digital files that delineate and identify:

  • SSM: Relative surface soil water content in percent for the first five centimetres of the soil profile
  • SWI: Relative soil water content in percent for the first meter of the soil profile

Known restrictions / limitations

Currently the SWI is only developed for Africa. Furthermore, extremely dry and wet areas (including densely vegetated areas) cannot be monitored and must be masked within the product.

Lifecycle stage and demand











All lifecycle stages:

  • Soil water information can support modelling to predict flooding and feed into an environmental assessment.

Pre-licensing & Exploration:

  • Soil water information to account for in logistics planning, seismic surveying, site selection and development


  • Soil water information to excavate through soft ground and manage logistics

Geographic coverage and demand

Demand and coverage is for SSM and SWI global.


OTM:065 Floodplain mapping  

OTM:072 Monitoring flash floods

OTM:074 Estimating ground bearing capacity

OTM:079 Identification of archaeological or burial sites


HC:1104 Identify soft and hard ground as areas of potentially poor source and receiver coupling

HC:1210 Identify soft ground to reduce environmental impacts

HC:2502 Identification of problem soils

HC:4303 Understand extent of lakes and wet areas for hazard assessment

HC:2502 Identification of problem soils


Input data sources

Radar: LR

Spatial resolution and coverage

Spatial resolution:

SSM: 1 km and 10 km

SWI: 10 km

Minimum Mapping Unit (MMU)

N/A (the product is directly based on the input data; the smallest unit is one pixel)

Accuracy / constraints

Thematic accuracy: All products are from 3rd parties and delivered as is accordance with the official documentation and validation of the respective products.

Spatial accuracy: 0.5 x pixel size

Accuracy assessment approach & quality control measures


Frequency / timeliness

Observation frequency: Daily, 1 km: 2004 – Apr. 2012; 10 km: Jan.2007– present/operational

Timeliness of deliverable: Near real time product. Both products are available at the same day as the input data (radar) are available.


Freely available from:

FP7 Project – Geoland2

The European Earth Observation Programme – COPERNICUS

Delivery / output format

Data type:

  • Raster formats

File format:

  • GeoTiff (standard - any other OGC standard file formats)


 Download product sheet.


Lead Author:GeoVille
Peer Reviewer:Hatfield Consultants


Maria Lemper, Jan Miltizer

Document Title:

Surface Soil Moisture (SSM) & Soil Water Index (SWI)

# of Pages:



Internal – Project consortium and science partners


External – ESA


This page has no comments.