Reliability Issue in Projections of the Impacts of Climate Change and Other Changes on Water Resources

Dejan Dimkić1


1 Jaroslav Černi Institute for the Development of Water Resources, Water Planning and Climate Change Department, Jaroslava Černog 80, 11226 Pinosava – Belgrade; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it



Important hydrological changes, or generally water resources changes, are being observed in Serbia, as well as in many other parts of the world. Many national and international projects and studies address climate change and its impact on water resources. Some focus solely on the impact of climate change, while others also assess the impact of land use changes and/or changes in human use of water. Generally, the majority of the outcomes of these projects and studies tell us not only that the availability of water resources in Serbia will decrease, but that there may also be significant differences between catchments. Even within a single catchment, depending on the climate and hydrological models used, the differences between the results of the initial and other assumptions made, and the impacts assessed can be small but often significant. The reliability of the projections receives little or no consideration. This paper discusses this topic and attempts to provide some guidelines.

Keywords: Availability of water resources, climate change, hydrologic changes, land use, reliability, water demand.





The term "water resource" generally refers to a body of groundwater or surface water. In the present paper, unless indicated otherwise, the term applies to a surface stream – river. When speaking about river water, the paper primarily considers mean annual flows. In the 20th century, particularly the period 1950-1960, Serbia's rivers registered a negative trend. This led to a large number of projects, studies and papers over the past ten years, which address the problem and future expectations based on certain initial assumptions. The results reported in this paper neither overestimate or underestimate the importance of particular projects; it is just that data from these projects were available to the author of the paper.