WHYCOS is a global programme developed in response to the scarcity, or even absence, of accurate data and information on freshwater resources in many parts of the world.  The programme addresses developing countries in particular, where it is difficult to access existing data due to the deterioration of observing networks or insufficient data management capabilities.

The ultimate objective of the WHYCOS programme is to promote and facilitate the collection, analysis, exchange, dissemination and use of water-related information by employing the most appropriate technologies that meet the needs of the countries involved and are economically sustainable and supported over the longer-term.


The Hydrological Cycle

WHYCOS is being developed in the form of independently implemented regional components, HYCOSs, which meet the priorities expressed by participating countries. The HYCOS components collectively form the building blocks for the WHYCOS programme, where hydrological and meteorological variables are captured and transmitted to national and regional databases to support the establishment and enhancement of global information systems.  These information systems supply reliable water-related data and information to planners, decision makers, scientists and the general public. WHYCOS has also been conceived as a vehicle for technology transfer, training and capacity-building.


The Hydrological Cycle
Picture modified after United States Geological Survey original)


WMO Secretariat, supported by the WHYCOS International Advisory Group, is ensuring that individual components are implemented in agreement with the global WHYCOS concept through the establishment of standards as outlined in WMO Technical Regulations, the Guide to Hydrological Practices and WHYCOS Guidelines.

By providing a framework of common guidelines and standards, WHYCOS enables the use of information from the regional HYCOSs for larger scale applications, such as research into the global hydrological cycle.

As a result of this work WHYCOS makes an important contribution to the work of other WMO and international scientific programmes which require water-related information. In particular it is a fundamental contributor to the development of the WMO Hydrological Observing System (WHOS), a simple web-based portal providing access to the near real-time streamflow data (both water level and discharge).