Linking Climate Change to Urban Water Infrastructure Design: Recent Advances and Shortcomings in Downscaling Methods

Climate models have been extensively used for assessing the climate change impacts. However, due to the current limitations on detailed physical modelling and computational capability, outputs from these models are provided at resolutions that are too coarse and not suitable for impact studies. Hence, different downscaling methods have been proposed for linking the coarse-scale climate change projections to extreme hydrologic processes at the required space and time scales. Of particular importance for urban infrastructure design are those procedures dealing with the linkage of the large-scale climate variability to the historical observations of the precipitation and temperature extreme processes at a location of interest. If this linkage could be established, then the projected change of climate conditions given by climate models could be used to predict the resulting changes of the precipitation and temperature characteristics at the given local site. Therefore, the main focus of the present paper is to provide an overview of recent advances and shortcomings in the downscaling of extreme rainfall and temperature processes from both theoretical and practical viewpoints. In particular, another focus of this paper is on the development of a technical guide to provide some guidance to water professionals in Canada on how to consider the climate change information in the design of urban water infrastructures.