WATer and Global CHange


Globally, the supply of freshwater far exceeds human requirements. However, it has been estimated that by the end of the 21st century these requirements begin to approach the total available water. Regionally, however, the water demand for agriculture, and domestic and industrial use is approaching, or already exceeds the supply, particularly in Southwestern USA, North Africa and Southeastern Asia. In many of these regions ground water storages are used in unsustainable ways in order to support the current water demand. This will certainly get worse with increasing population and societies changing water demands, a situation exacerbated by the need to maintain river flows for ecological and human services.
In addition WATCH will provide new insights into the inter-relationships between water, climate change, and the anthropogenic pressures upon global water systems. A global overview of the exposure of society to deteriorating water quality brought on by global-scale changes in climate, population, land use, and human activities will be obtained, leading into the development of a first model of global water quality indicators in which CESR plays a decisive role.
The aim of this new water quality sub-model is to determine chemical fluxes in different pathways which will allow a combination of water quantity with water quality analyses. The simulated key water quality variables have been chosen to indicate the suitability of water for various purposes: household, industrial and agricultural use, as well as for the overall health of the aquatic ecosystem. Thus, the variables in the first phase will include:

  • total dissolved solids (TDS),
  • biochemical oxygen demand (BOD),
  • total coliform bacteria (TC),
  • water temperature (TW), and
  • dissolved oxygen.

In close cooperation with the SCENES project, necessary point source and diffuse loading information was prepared as input data for the in-stream water quality modelling within WATCH.

Funding agency


Project duration

February 2007 − January 2011

Project management

Joseph Alcamo
Frank Voß

Project staff

Ellen Kynast