Follow Us

Changes in Water Availability

Water figHow can we better understand and predict precipitation variability and changes, and how do changes in land surface and hydrology influence past and future changes in water availability and security? These questions focus on the exploitation of improved data sets of precipitation, soil moisture, evapotranspiration, and related variables such as water storage and sea surface salinity expected in the coming five years to close the water budget over land and provide improved information for products related to water availability and quality for decision makers and for initializing climate predictions from seasons to years ahead. The improvements will come from ongoing and planned satellite missions as well as greater use of in situ observations; their evaluation and analysis to document mean, variability, patterns, extremes and probability density functions; their use to confront models in new ways and to improve our understanding of atmospheric and land surface processes that in turn feed into improved simulations of precipitation; and new techniques of data assimilation and forecasts that can lead to improved predictions of the hydrological cycle across scales, from catchments to regional to global, including hydrogeological aspects of ground water recharge. In particular need of attention is the use of realistic land surf ace complexity with all anthropogenic effects taken into account, instead of a fictitious natural environment. This encompasses all aspects of global change, including water management, land use change, and urbanization. The ecosystem response to climate variability and responsive vegetation must be included, as must cryospheric changes such as permafrost thawing and changes in mountain glaciers. These results should all lead to improved understanding and prediction of precipitation and water variability, enhance the evaluation of the vulnerability of water systems, especially to extremes, which are vital for considerations of water security and can be used to increase resilience through good management and governance."... read the white paper


Challenges and Opportunities in Water Cycle Research: WCRP Contributions by Kevin E. Trenberth and Ghassem R. Asrar, Surveys in Geophysics, (2014) 35:515-532, DOI 10.1007/s10712-012-9214-y


WCRP Strategy for Workshop for Global Water: Resource Systems, 5-7 June 2013, Saskatoon, CANADA 

WCRP Stategy Workshop on Observations and Prediction of Precipitation, 27-28 June 2013, Fort Collins, CO USA 

Trending Now: Water, 7th GEWEX International Scientific Conference, 14-17 July 2014, The Hague, The Netherlands