Climatic Change Impact on Water Resources in a Systems Perspective

Global climate change related to natural and anthropogenic processes has been the topic of concern and interest world wide. Despite ongoing research efforts, the climate predictions cannot be rated any better than speculative or possible scenarios whose probability of occurrence is, at the present stage, impossible to assess. One of the most significant impacts of the ‘greenhouse effect’ is anticipated to be on water resources, including different elements of the hydrologic cycle, water supply and demand, regional vulnerability, and water quality. Thus, the impact of climate change appears to be an additional component on top of the large number of existing water-related problems. The existence of the greenhouse effect, the increase of greenhouse gas emissions, and the rise of corresponding concentrations are things that are certain. However, their impacts on hydrology and water management are highly uncertain. In the latter area, one needs information on much smaller spatial and temporal scales than those used in climate studies. The objective of the present paper is to analyze the climate change impact on water resources in a system's perspective, to discuss scientific gaps, and challenge scientific issues. The role of different scales and uncertainties, as well as the hydrological view of global circulation models are also discussed. Our preparedness for probable global (climate) change is reviewed in terms of assessment, planning, design and adaptation. Copyright Kluwer Academic Publishers 1997