TOWARDS A WORLD HYDROLOGICAL CYCLE OBSERVING SYSTEM

There are considerable difficulties in assembling global hydrological data sets in near real time, data that might be used for deciding inve stment for sustainable water resources development and management, for environmental protection and for studying global change. Several reas ons exist for these difficulties, a new one is that many countries hav e recently been cutting back on hydrological networks and the services that operate them. This means that knowledge of the World's water res ources is getting worse when the global demand for water is accelerati ng. By way of contrast, meteorologists have ready access to large volu mes of global data, much of it in real time, principally through WMO's World Weather Watch (WWW). A World Hydrological Cycle Observing Syste m (WHYCOS) is proposed to facilitate access to global data and support hydrological services in need. A world-wide network of about 1000 sta tions is planned for the largest rivers, together with associated data bases and products to meet the needs of users. WHYCOS would start in Africa with a 100-station network and be expanded to other regions. It is a necessary tool for averting the coming water crisis and essentia l to the drive towards sustainable development.