ABSTRACT
For floodplain mapping in riverine environments, statistical frequency analysis is performed on high river flows to obtain a set of design flow values corresponding to selected frequencies of occurrence, commonly interpreted in terms of return periods or annual exceedance probabilities (AEPs). For urban settings, the same statistical approach is used to develop precipitation intensity-duration-frequency estimates, which are then integrated with urban hydrological models to produce desired design flow values. The estimated design flows are then used in hydraulic models to generate flood extents and levels for the creation of flood inundation and other flood related maps and products. For coastal environments, design water levels are obtained through a suitable combination of various wave characteristics, wave run-up, and storm surge elevations and the estimates of desired design water levels corresponding to selected AEPs are obtained using conventional or joint frequency analysis approaches. Irrespective of floodplain setting, the design water levels, estimated based on historical observations and assuming a stationary climate, will not be representative of future conditions due to projected climate change and therefore appropriate provisions for climate change need to be considered. This paper focuses on climate adaptation of Canadian floodplain maps, by documenting available approaches for integrating climate change information with floodplain mapping. The outcome of the study is important to inform future land use planning and development and therefore to avoid potential damages that may occur due to future floods.
