Climate Change: A Growing Challenge for Water Management in Developing Countries

Abstract

Water managers today are faced with the daunting task of evolving management strategies and policies in the face of not only the large uncertainty associated with the climate change impacts but also, to some extent, a sense of perplexity and confusion that the issue of climate change seems to have created because of conflicting views, opinions and even scientific projections on the impending regional water situations. Such a sense of confusion is particularly pronounced in the developing countries, where the capacity to understand the different issues of climate change as it affects the water systems is extremely limited among water managers. They are aware that they must cope with abnormal situations more frequently than they used to, that the future is not likely to be similar to the past and that therefore they need guidance from the scientific community in dealing with the evolving situation. Even a small part of the huge amount of scientific work dealing with impacts on water availability, water demands, water quality and frequencies and magnitudes of floods and droughts has, however, not yet found its way into policy interventions and decision making. Impact studies relevant to water resources management address situations of decreasing water supply and simultaneous increase in water demands. Downscaled projections of temperature, precipitation, windspeed, relative humidity and net radiation are typically used for assessing the future irrigation (and other) water demands; projections of streamflow, obtained either directly by downscaling or through use of a hydrologic model, are used in assessing impacts on the water supply and water quality. The ensemble approach that uses climate simulations from a large number of models for several future scenarios is commonly used to address the model and scenario uncertainties. Use of hydrologic models in impact studies in river basins brings along an additional source of uncertainty due to the usually large number of parameters calibrated based on limited historical data, and assumed stationarity over the future period. Such uncertainties at all levels of impact assessment— from climate models to emission scenarios, downscaling and hydrologic models—seem to discourage the water managers from using the results of climate impact studies. Additionally, the impacts and adaptive responses are generally provided for a far-distant time Water Resour Manage (2013) 27:953–954 DOI 10.1007/s11269-012-0223-x