WMO Strategic Priority: WIGOS and WIS, Polar and High Mountain Regions, Capacity Development
Status: Ongoing
Funding: Contributions by participating countries
Implementation in: Canada, Denmark, Finland, Iceland, Norway, Russian Federation, Sweden, USA
Project Partners: WMO

The Arctic-HYCOS project aims to collect and share hydrological data and information for the Arctic basin to enable better climate research and predictions in the Northern Hemisphere. The project serves as a vital platform for the regular collection and free exchange of Arctic hydrological data from all participating nations. The available real-time and historical data is intended to allow researchers to:

  1. evaluate freshwater flux to the Arctic Ocean & Seas,
  2. monitor changes and enhance understanding of the hydrological regime of the Arctic region, and
  3. estimate flows in ungauged regions and develop models for enhanced hydrological prediction in the Arctic.


The map interface below displays the Arctic-HYCOS Basic Network of Hydrological Stations (BNHS) created from a selection of existing stations from the national hydrological networks in the Arctic basin. The stations can be filtered at the bottom of the map.

Each station on the map interface has a pop-up menu providing essential station’s metadata as well as a link to a webpage with the station's real-time and/or historical time series data available through the WMO Hydrological Observing System (WHOS). For each time series, any available time period of interest can be selected, plotted and downloaded in OGC NetCDF (CF conventions)OGC WaterML 2.0 or CUAHSI WaterML 1.0 formats. The time series metadata are harmonized by means of the WHOS Hydrological Ontology providing semantic interoperability among heterogeneous information sources. 


Find out more on the WHOS Community site.


Project Steering Committee Meeting Minutes

  • Freshwater Ice and Water Temperature: Manuals, Standard Practices and Standard Operating Procedures – Annotated Bibliography
  • Freshwater Ice and Water Temperature: Manuals, Standard Practices and Standard Operating Procedures – Summary

The definitions below relate to attributes of the Arctic-HYCOS data and information for each station.

Basic Network of Hydrological Stations

The Arctic-HYCOS Basic Network of Hydrological Stations (BNHS) station list was created from a selection of existing stations from the national hydrological networks in the Arctic basin. There are two sub-networks - Network A is all stations in the Arctic-HYCOS database, and Network B includes only those stations that represent flow-to-ocean.

Hydrological Regime (Network A)

Stations suited to study changes in the Arctic hydrological regime (covering the entire land mass draining into the Arctic Ocean and northern seas).

  • At least one station per watershed in the land mass draining into the Arctic Ocean and northern seas;
  • Stations are chosen to represent a variety of characteristics of hydrological regimes within the permafrost zone (e.g. varying drainage basin sizes).

Flow-to-ocean (Network B)

Stations that are the most downstream monitoring stations on rivers flowing to the Arctic Ocean and northern seas. These stations can be used to estimate total freshwater Flux to the Arctic.

  • Restricted to stations with a drainage area >5000 km2 (if drainage areas are smaller than this, suitable upstream stations are selected in their place).
  • This is a subset of the Hydrological regime stations in Network A.


Drainage area

The drainage area of a basin or catchment representing the area of land upstream from the hydrometric gauge where topography causes falling precipitation to collect in the same creeks, streams, rivers, lakes, and reservoirs, the outflow for which is at the gauge location. The Arctic-HYCOS database includes the gross drainage area and the effective drainage area for each gauge, in km2 .

The Drainage_shapefile variable indicates whether a vector shapefile for the total drainage area corresponding to the hydrometric station is available (1) or not (0) from the operating country/institute.



This attribute is intended to identify whether the basins represented by hydrometric stations have “significant” regulation or diversions in the upstream river system. This designation reflects only the physical structures within the waterways upstream of the site; it does not reflect the land use within the basin.

Regulated (1): Basins with structures providing significant flow regulation, based on the host country’s standards. The definition for “significant regulation” may vary by country, as defined in the metadata field “regulation_definition”. If no standard is available, “regulated” is defined as basins with structures controlling more than 5% of the basin area.

No Significant Regulation (0): If there are no significant regulation structures upstream from the station, or diversions within the river system, based on the country’s definition. This generally represents “natural” flow conditions, but not necessarily “pristine” basin conditions.

  Definition for a "regulated" station in each country
Canada Over 5% of the estimated drainage area affected by regulatory structures.
Norway More than 2% regulated catchment area.



Land Use Change

Significant land use changes that result in changes to the flow regime. A “significant” amount of land use change in a basin is defined as a modification of over 10% of the surface area of the station’s drainage area (Environment Canada, 1999).

Land use change:
1: if there has been significant land use  change in the basin;

0: if there is no significant change.


Project Steering Committee Chair and Members

Canada Flad



Environment and Climate Change Canada, Water Survey of Canada

Project Steering Committee Secretariat

Mr Jeffrey Karn

National Hydrological Services, Environment and Climate Change Canada
Toronto, Canada


Finland flag



Dr. Jari Uusikivi

Finnish Environment Institute (SYKE)
Helsinki, Finland


Iceland flag



Dr. Jorunn Hardardóttir

Icelandic Meteorological Office
Reykjavik, Iceland


Norway flag



Dr. Hege Hisdal

Norwegian Water Resources and Energy Directorate (NVE)
Oslo, Norway 


Russian Flag

 Russian Federation


Prof. Valery Vuglinsky

State Hydrological Institute of Roshydromet
St. Petersburg, Russia


Sweden Flag



Dr. David Gustafsson

Swedish Meteorological and Hydrological Institute (SMHI)
Norrkoping, Sweden


Us flag

 United States of America


Mr. Jeff Conaway

U.S. Geological Survey (USGS)
Anchorage, Alaska



Global Runoff Data Centre


Mr. Ulrich Looser

Global Runoff Data Centre (GRDC)
Federal Institute of Hydrology (BfG)
Koblenz, Germany