The Global Terrestrial Network – Hydrology (GTN-H) links existing networks and systems for integrated observations of the global water cycle.The network was established in 2001 as a "network of networks“ to support a range of climate and water resource objectives, building on existing networks and data centres, and producing value-added products through enhanced communications and shared development. The GTN-H is a joint project of the Global Climate Observing System (GCOS), the World Meteorological Organization / Climate and Water Department (WMO/CLW), and the Global Terrestrial Observing System (GTOS). The GTN-H website is a gateway to a great number of global observing systems for hydrological data. You can find descriptions and links to all network partners of GTN-H and the hydrological data products developed under the cooperation the network.

GTN-H Data Access

Updated February 2, 2011

Program Management

For over 65 years, the World Meteorological Organization (WMO) and its predecessor, the International Meteorological Organization, have supported National Hydrological Services, River Basin Authorities and other institutions responsible for water management in a wide range of activities which together form the Hydrology and Water Resources Programme of WMO (HWRP). The GTN-H network was established in 2001 as a 'network of networks' to support a range of climate and water resource objectives, building on existing networks and data centres, and producing value-added products through enhanced communications and shared development. The GTN-H is a joint project of the Global Climate Observing System (GCOS), the World Meteorological Organization/Climate and Water Department (WMO/CLW), and the Global Terrestrial Observing System (GTOS). The GTN-H aims at providing hydrological information for improved climate and weather prediction, detection and attribution of climate change, impact assessment of climate change, the assessment of freshwater sustainability, and better understanding of the global water cycle.

• GTN-H Network partners
• GTN-H & GEOSS
• Configuration of the Network

Objectives and Activities

Developing and improving the availability of hydrological data and information required to address global and regional climate, water resources and environmental issues is a prime objective of GTN-H.

Benefits include:

• improved weather and climate prediction
• hydrological characterization to detect climate change
• ability to predict the impacts of change
• an understanding of the global water cycle in an integrated context of weather, water and climate.
• Other benefits will be the improved assessment of freshwater availability and variability, and the greater understanding of large-scale hydrological processes.

Central to achieving these objectives is the development of global-scale data products. A major area of activity within GTN-H aims to develop and implement improved approaches and tools for data collection, access and management to support GTN-H objectives, and here GTN-H is a key partner in implementation of the Integrated Global Water Cycle Observation (IGWCO) theme of the IGOS partners.