completely flood extensive low-lying or estuarine areas) or two-dimensional 

 effects (e.g., flow divergence or convergence) cause tsunami runup elevations 

 to differ from elevations at the shoreline. It is recommended that inundation 

 limits for these areas be determined using a numerical model developed at the 

 US Army Engineer Waterways Experiment Station (Houston and Butler 1979). This 

 model is capable of handling land flooding for bays, harbors, developed areas 

 such as cities, large low-lying areas, sand-dune protected areas, and other 

 areas where there are topographical, roughness, or coastline variations. There 

 are also locations at river mouths where the formation of a bore will affect 

 the runup elevations. This problem can be efficiently treated using the 

 method of characteristics. 



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