Tuesday, April 14, 2009
Climate change and water management
Hydroelectric generation in Québec, both from very large existing and foreseen power plants, represents an important economic activity. From the perspective of both economics and Quebeckers' energy security, it is clearly important to determine the impacts of climate change on the currently installed generation capacity. This must also be borne in mind when planning future facilities, since the time constants of climate change correspond closely with the planning horizon for large hydroelectricity stations. We recognize the uncertainty related to the impacts of climate change on water resources, partly because of the inappropriate scale at which global climate projections are available. However, in recent years, we have made important progress in downscaling climate projections to a resolution compatible with hydrological studies. We have gained confidence that the analysis of climate change impacts are becoming relevant and should be considered in water management practices and the design of future hydraulic structures.
The Regional Climate Models (RCMs) were developed and improved as a potential tool to provide climate projections at the watershed scale. These model's main advantage is that they are constructed with balanced land and atmosphere water and energy budgets, and includes feedbacks between the surface and the atmosphere. Many of our analyses have provided information on the Canadian RCM's level of confidence and on its limitations for use in hydrological studies of climate change. Even though the approach has uncertainties, it was found to provide useful information and hence should be considered seriously by water resource managers. One of the keys is to make use of more than a single regional climate projection (use an ensemble), thus allowing for the evaluation of the climate change signal and its associated level of confidence; this will provide more trustworthy climate change information. Such an approach is already applied at Hydro-Québec in the long-term planning of its water resources for hydroelectric generation over the Québec territory. The organisation has opted for an adaptation strategy as a means to avoid abrupt and costly changes as climate begins its evolution towards important changes.
The talk will first introduce the science of climate modelling. Our validation of the simulated climate data will be explained and finally, water management applications using simulated climate data will be presented.
Dr. Daniel Caya is senior Research Scientist, Head of Climate Simulations Team (CST) at the Ouranos Consortium, and Adjunct Professor at the Centre ESCER, UQÀM. He is in charge of generating the national climate-change projections to be used for Impacts and Adaptation studies in Canada. He received his PhD while developing the prototype of the Canadian Regional Climate Model (CRCM) and produced the first multi-month simulations with the model. He is member of the CRCM Network since day one, and hence possesses a strong overall expertise in regional climate modelling. He played a key role in the rapid evolution from the prototype version of CRCM to its operational form. From 1997 to 2001, his full time was dedicated to the CRCM Network in which he was deputy leader. He joined the Ouranos Consortium in August 2001 to plan and develop the national regional climate-change projection programme, and lead the Ouranos CST (10 people). He was heavily involved in the training of most of the Canadian Highly Qualified Personnel in regional climate modelling. Daniel Caya was contributing author in the Working Group 1 (The Physical Science Basis of Climate Change) of the IPCC fourth assessment report.