Review of climate change impacts on reservoir hydrology and long-term basin-wide water resources management

Abstract

Global climate change is known to trigger local and regional hydrologic variations like changes in precipitation patterns, increased surface temperatures and more frequent floods and droughts. Apt and efficient water management is extremely important as climate change can considerably affect the water supply-demand balance. Focusing on reservoirs and their management, the vulnerability to floods and droughts, effect on the energy production, ability to cope with the agricultural and drinking water demand and impact on ecological flow are needed to be reconsidered under climate change scenarios. The objective of this paper is to review and identify the impacts of climate change on reservoir hydrology, discuss about the related uncertainties and conclude and recommend the ways of adapting to the change focusing on future climate prediction scenarios such as baseline scenarios and climate change impact on estimation of streamflow using rainfall-runoff based hydrological models, reservoir studies using water balance based hydrological models, with further emphasis on reservoir hydrology and adaptation methods. Previous studies have highlighted the severity of climate change impacts and the importance of conducting further research on this area. In the case of reservoir operation, emphasis is on the consequent need of closer attention by the planners and reservoir operators as a major requirement. Variations in precipitation patterns affect the hydropower generation since the streamflow varies with the rainfall and also those variations act as a reason for aggravated floods and droughts. Changes in the evaporation volumes both from soil and reservoir surfaces with increased temperature and changes in the demand affect the irrigation and drinking water supplies considerably. Focusing on above, an approach based on reservoir operation and water balance was discussed in the study in an attempt to identify the ways of adapting to the identified adverse impacts of the impending climate change and based on the research findings, it is recommended to stress more on the ways of reducing climate change impacts in future studies.