Author(s): Van Thanh Van Nguyen
Linked Author(s):
Keywords: Extreme rainfall processes Downscaling methods Climate change impacts Urban infrastructure design Scale invariance method
Abstract: Extreme rainfalls of short time scales (from a few minutes to less than one day) are often required for the design of urban infrastructures. These data are often limited or unavailable at the location of interest while those for the daily scale are widely available. Hence, it is important to develop a modeling method that could describe accurately the statistical properties of the extreme rainfall processes over a wide range of time scales so that short-duration rainfalls can be estimated from those of longer durations. In addition, climate change has been recognized as having a profound impact on hydrologic processes for a local site or over an urban catchment area. Hence, global/regional climate models have been extensively used in climate change impact and adaptation studies. However, due to the current limitations on detailed physical modelling and computational capability, outputs from these climate models are provided at resolutions that are too coarse and not suitable for these impact studies. Consequently, downscaling methods are needed for linking these coarse-scale climate change projections to the historical observations of extreme hydrologic processes at a location of interest. Therefore, the main focus of this paper is to provide an overview of some recent advances and shortcomings in the modeling of extreme rainfall processes in the climate change context from both theoretical and practical viewpoints. More specifically, a scale-invariance (scaling) approach is introduced to establish the linkages between rainfall characteristics over the wide range of space and time scales. Results of an illustrative application using historical rainfall records from a network of 74 raingages located across Canada have indicated the feasibility and accuracy of the proposed scale-invariance downscaling method.
Year: 2025