EGU21-9400, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The brokering framework empowering WMO Hydrological Observing System (WHOS)

Enrico Boldrini1, Paolo Mazzetti1, Fabrizio Papeschi1, Roberto Roncella1, Mattia Santoro1, Massimiliano Olivieri1, Stefano Nativi2, Silvano Pecora3, Igor Chernov4, and Claudio Caponi4
Enrico Boldrini et al.
  • 1National Research Council of Italy (CNR), Institute on Atmospheric Pollution Research (IIA), Sesto Fiorentino (FI), Italy (
  • 2European Commission, DG Joint Research Centre (JRC), Ispra (VA), Italy (
  • 3Po River Basin Authority, Parma (PR), Italy (
  • 4World Meteorological Organization, Geneve, Swiss (

The WMO Commission of Hydrology (CHy) is realizing the WMO Hydrological Observing System (WHOS), a software (and human) framework with the aim of improving sharing of hydrological data and knowledge worldwide.

National Hydrological Services (NHS) are already sharing on the web (both archived and near real time) data collected in each country, using disparate publication services. WHOS is leveraging the Discovery and Access Broker (DAB) technology developed and operated in its cloud infrastructure by CNR-IIA to realize WHOS-broker, a key component of WHOS architecture. WHOS-broker is in charge of harmonizing the available and heterogeneous metadata, data and services making the already published information more accessible to scientists (e.g. modelers), decision makers and general public worldwide. 

WHOS-broker supports many service interfaces and API that hydrological application builders already can leverage, example given OGC SOS, OGC CSW, OGC WMS, ESRI Feature Service, CUAHSI WaterOneFlow, DAB REST API, USGS RDB, OAI-PMH/WIGOS, THREDDS. New API and service protocols are continuously added to support new applications, being WHOS-broker a modular and flexible framework with the aim of enabling interoperability and assuring it as the standards will change/evolve through time. 

Three target programmes have already benefited from WHOS:

  • La Plata river basin: hydro and meteo data from Argentina, Bolivia, Brazil, Paraguay, Uruguay are harmonized and shared by WHOS-broker to the benefit of different applications, one of them is the Plata Basin Hydrometeorological Forecasting and Early Warning System (PROHMSAT-Plata model, developed by HRC), based on CUAHSI WaterOneFlow and experts from the five countries.
  • Arctic-HYCOS: hydro data from Canada, Finland, Greenland, Iceland, Norway, Russia, United States are harmonized and shared by WHOS-broker to the benefit of different applications, one of them is the WMO HydroHub Arctic portal, based on ESRI technologies.
  • Dominican Republic: hydro and meteo data of Dominican Republic published by different originators is being harmonized by WHOS-broker to the benefit of different applications, one of them is the Met data explorer application developed by BYU based on THREDDS catalog service.

The three programmes should act as a driving force for more to follow, by demonstrating possible applications that can be built on top of WHOS.

The public launch of WHOS official homepage at WMO is expected by mid 2021, will include:

  • A dedicated web portal based on Water Data Explorer application developed by BYU
  • Results from the three programs
  • Detailed information on how to access WHOS data by using one of the many WHOS-broker service interfaces
  • An online training course for data providers interested in WHOS
  • The WHOS Hydro Ontology, leveraged by WHOS-broker in order to both semantically augment user queries and harmonize results (e.g. in case of synonyms of the same concept in different languages).

How to cite: Boldrini, E., Mazzetti, P., Papeschi, F., Roncella, R., Santoro, M., Olivieri, M., Nativi, S., Pecora, S., Chernov, I., and Caponi, C.: The brokering framework empowering WMO Hydrological Observing System (WHOS), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9400,, 2021.

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