Indicators for World Water Assessment Programme


Human management of the terrestrial water cycle and its impact on freshwater resources is gaining explicit recognition in the debate on global environmental change and sustainable development (ICSU/WFEO 2004, Scholes and Hassan 2005, Vörösmarty et al. 2005b). As part of this concern is the growing recognition that in-country information resources -for both water quantity and quality - upon which water resource assessments have traditionally been based and which is targeted as part of the World Water Assessment Programme reporting procedures, have been in severe decline over the last two decades (IAHS 2001). In many parts of the developing world (e.g. Africa) the problem has been particularly acute. At the same time, state-of-the-art data sets from the Earth Systems Sciences, while an otherwise rich information resource, have been poorly harmonized and integrated with socioeconomic studies of water resources or assessments more generally (Vörösmarty 2002).

The UNH Water Systems Analysis Group has developed a compendium of Earth System and socio-economic databases describing the current state of global water resources, including associated human interactions and pressures. The group has integrated a wide array of satellite-derived and land-based monitoring products from around the world with regional and country-level socio-economic data. The Group has been committed to the wide dissemination of our data products, for example the global RivDIS data sets derived from the UNESCO Discharge of Selected Rivers of the World series, as well as regional applications for South America (R-HydroNET and LBA-HydroNET on behalf of UNESCO-ROSTLAC) and across the pan-Arctic (R-ArcticNET and Arctic-RIMS, the largest such data bases available worldwide).

Prior analysis at the global scale demonstrated the importance of such information resources (Vörösmarty et al. 2000) in more clearly articulating the scope of global water scarcity. Substantial increases in the previously-estimated number of people under water-related stress were estimated using high resolution geospatial data sets. A recent study in otherwise data poor Africa (Vörösmarty et al. 2005a) demonstrates the utility of such geospatial data sets in a wide range of indicator applications that are anticipated to be of value to WWDR-II as well. Methods have been developed based on hydrological modeling, observed hydrographic records and the topology of digital river networks to track the condition of renewable water resources under mean conditions, with respect to inter and intra-annual variability, for population exposure to severe drought, and for multiple water withdrawals in basins along mainstem rivers.

This digital archive presents a series of thematic data sets that are specifically intended to support, both quantitatively and visually, the forthcoming WWDR-II report. The accompanying tables lists these data sets, their key attributes, and references that should be cited in the use of this information. The users are welcome to contact the data developers at the University of New Hampshire ( for questions and comments.


ICSU/WFEO. 2004. Harnessing Science and Technology for Sustainable Development: Water, Sanitation and Human Settlements. Dialogue Paper by the Scientific and Technological Community to the Twelfth Session of the Commission on Sustainable Development (CSD12), 19 - 30 April 2004. The International Council for Science (ICSU) and the World Federation of Engineering Organisations (WFEO) as organizing partners of the Scientific and Technological Community.

IAHS (Ad Hoc Group on Global Water Data Sets.) 2001. Global water data: A Newly Endangered Species. Co-authored by C.J. Vörösmarty (lead), A. Askew, R. Barry, C. Birkett, P. Döll, W. Grabs, A. Hall, R. Jenne, L. Kitaev, J. Landwehr, M. Keeler, G. Leavesley, J. Schaake, K. Strzepek, S.S. Sundarvel, K. Takeuchi, and F. Webster. AGU Eos Transactions 82:5 54, 56, 58.

Scholes, R. and R. Hassan (Working Group Leaders). 2005. The Millennium Ecosystem Assessment, Volume 1: Conditions and Trends Working Group Report. Island Press. In press.

Vörösmarty, C.J., P. Green, J. Salisbury, and R. Lammers. 2000. Global water resources: Vulnerability from climate change and population growth. Science 289: 284-288.

Vörösmarty, C.J. 2002. Global water assessment and potential contributions from earth systems science. Aquatic Sciences 64: 328-351.

Vörösmarty, C.J., E.M. Douglas, P.A. Green, and C. Revenga. 2005a. Geospatial indicators of emerging water stress: An application to Africa. Ambio. In press.

Vörösmarty, C.J., C. Leveque, C. Revenga (Convening Lead Authors). 2005b. Chapter 7: Fresh Water. In: Millennium Ecosystem Assessment, Volume 1: Conditions and Trends Working Group Report. Island Press. In review