A new chapter on image velocimetry has been added by the World Meteorological Organization to its Guide to Hydrological Practice, providing information to its members on the benefits of these innovative cost-effective methods for measuring rivers and streams.
“The inclusion of image velocimetry in the WMO Guide provides confidence and clarity on the use and applicability of these techniques,” the WMO said in a statement. “By adding this chapter, WMO signals to practitioners, institutions and decision-makers that these methods, after years of innovation, testing and collaboration across the global community, are no longer experimental, but part of the recognized hydrometric toolkit.”
Image velocimetry uses cameras and video analysis to estimate surface flow velocities in rivers and streams. Compared with traditional methods, it is safer, often more cost-effective, and applicable in situations where conventional instruments are difficult or risky to use. From flood monitoring to remote river gauging, they open up new opportunities to strengthen observations networks for modern hydrological services.
For managers and leaders in national meteorological and hydrological services, the inclusion of image velocimetry in the guidance can help overcome resistance or hesitancy towards emerging technologies, the WMO says, as it “shows that image-based approaches are ready for wider adoption and investment, delivering more data, safer operations, and stronger resilience in the face of water-related challenges”.
The WMO Guide to Hydrological Practice, Volume I: Hydrology – From Measurement to Hydrological Information (WMO-No. 168, 2025) can be viewed here.
In related news, the Woods Hole Oceanographic Institution (WHOI) is participating in a new research initiative aimed at enhancing the understanding of extreme weather, such as hurricanes, using ocean data. Read the full story here