文摘
Flood hazard modeling is an important task for decision making in the flood management aiming at preventing human and material losses. There is therefore a pressing need for reliable predictive tools in order to identify flood-prone areas. Recently, with the increase in cheap computational power, most studies in this context use one- or two-dimensional (1-D, 2-D) deterministic hydraulic models, which provide estimates of the flood extent and depth with satisfactory accuracy at reduced time. These models, however, capture only a relatively small fraction of the active processes by simulating flood without consideration of morphological change, while 2-D/3-D hydro-morphodynamic solutions are more realistic by considering the influences of channel and floodplain morphologies to simulate inundation flow. This research seeks to assess the suitability of a landscape evolution model (LEM) to simulate adequately the hydraulics of flood events in a real case scenario. We opted to use the 2-D model cellular automaton evolutionary slope and river (CAESAR) which is originally a LEM that has recently undergone a real evolution by integrating the hydrodynamic flow routing algorithm LISFLOOD-FP (LF). CAESAR-LISFLOOD (CAESAR-LF) is a reduced-complexity and depth-integrated 2-D storage cell model that simulates flow and sediment transport in response to hydrological inputs. The area is an urban reach of the river Bouregreg (Morocco) having a large and swampy floodplain with complex topography. Performance of the reduced-complexity model CAESAR-LF in flood mapping is investigated and benchmarked against the one-dimensional (1-D) hydraulic model Hydrologic Engineering Center River Analysis System (HEC-RAS). Combined climate and hydrologic modeling were used to generate input flow data for hydraulic models. The results from both approaches agree well and show a relative good consistency in estimating flood extent and magnitude. Some differences occur, but these can easily be explained as a result of unavoidable differences in concepts and implementation.
