Stakeholders and user communities
SoMMet engaged with stakeholder and user communities across metrology, environmental research, Earth observation, agriculture and water management. The project developed methods, tools and guidance to support traceable, comparable and harmonised soil moisture measurements across spatial scales.
Stakeholder Advisory Committee
During the project, the SoMMet Stakeholder Advisory Committee brought together external expertise from meteorological services, Earth-observation organisations, research institutions, universities and industry. The committee provided perspectives on user needs, potential applications and routes for the uptake of the project's results.
For data-protection reasons, individual contact details are not published.
The participating organisations are listed below in alphabetical order:
- ICWRGC, International - International Centre for Water Resources and Global Change (UNESCO and Bundesanstalt für Gewässerkunde (BfG), German Federal Institute of Hydrology)
- KU, Denmark - University of Copenhagen, Department of Geosciences and Natural Resource Management
- NIBIO, Norway - Norwegian Institute of Bioeconomy Research, Division of Environment and Natural Resources
- NMBU, Norway - Norwegian University of Life Sciences, Faculty of Science and Technology
- Manufacturers and developers of point-scale soil moisture sensors and CRNS systems
Soil moisture instrumentation and calibration services
SoMMet's results are relevant to manufacturers and developers of point-scale soil moisture sensors and cosmic-ray neutron sensing (CRNS) systems, as well as to calibration laboratories and providers of related measurement services.
For point-scale measurements, the project established and compared primary reference methods for determining soil water and moisture content, developed portable transfer standards and implemented calibration facilities. Commercial point-scale sensors were tested against traceable reference values. The observed differences between individual instruments and sensor types demonstrated the practical importance of sensor-specific calibration and uncertainty evaluation.
For CRNS, commercially available detector types were characterised in neutron reference fields, and their neutron response functions and associated uncertainties were evaluated. SoMMet also assessed neutron-transport models and developed guidance for calibrating CRNS systems under outdoor conditions. These results provide manufacturers, calibration providers and users with a stronger technical basis for evaluating instrument performance and improving calibration and validation procedures. They can also support the future development of more comparable equipment and services.
Monitoring networks and environmental services
Meteorological and hydrological services, agrometeorological organisations, environmental monitoring networks and Earth-observation communities rely on soil moisture data obtained using different instruments and at different spatial scales.
SoMMet compared point-scale sensors, CRNS measurements and satellite products at three agricultural test field sites. The project examined how their sensing domains, uncertainties and responses to environmental conditions affect the comparability of their results. This work showed that soil properties, vegetation, land management and the spatial representativeness of observations must be considered when measurements obtained using different methods are interpreted and compared.
The project translated these findings into practical guidance for CRNS field calibration and for harmonising soil moisture datasets in terms of measurement units, temporal resolution, measurement depth and lateral scale. It also demonstrated proof-of-concept approaches for combining ground-based and satellite observations. The resulting methods and guides provide a basis for improved quality assurance, network design, dataset comparison and satellite-product validation. Their uptake can support more consistent soil moisture information for hydrological modelling, weather and climate services, and drought and flood assessment.
Agriculture and water management
Farmers, agronomists, irrigation advisers, water authorities and environmental managers use soil moisture information to assess water availability and changing conditions in soils and agricultural landscapes.
The SoMMet field campaigns compared measurements from point-scale sensors, CRNS systems, soil sampling and satellite observations at agricultural test sites. The results highlighted that different methods do not necessarily respond in the same way to irrigation, vegetation and spatial variability. Calibration, measurement uncertainty and spatial representativeness therefore need to be considered before the resulting data are used to support operational decisions.
The project’s calibration procedures, harmonisation workflow and data-fusion guidance can help users select and combine measurements appropriate to a particular field, catchment or management task. A proof-of-concept combination of CRNS and Sentinel-1 observations demonstrated the potential to produce spatial soil moisture information over areas relevant to irrigation districts and agricultural drought monitoring. In the longer term, more traceable and comparable measurements can contribute to irrigation planning, drought and flood assessment, and the sustainable management of soil and water resources. Achieving these benefits requires local validation and the integration of soil moisture observations into appropriate agronomic or hydrological decision-support systems.