Maximum Fluid Forces in the Tsunami Runup Zone

The analytic and numeric models of the fully nonlinear shallow-water theory are used to compute the temporal and spatial variations of water depth and flow velocity of tsunami runup on a uniformly sloping beach, from which the momentum flux is evaluated. The momentum flux is proportional to the drag force for a surface-piercing stationary object of the unit breadth being placed vertically over the flow depth. The envelope of the extreme momentum flux in the runup/rundown process is established. The actual force acting on a specific object must be computed with its appropriate drag coefficient.