The hydraulic characteristics of flow through channels are an important component of fish habitat. Salmonids have evolved in stream systems in which water velocity and flow depth vary spatially within the watershed and temporally on a daily, seasonal, and annual basis. Flow requirements vary during different phases of the freshwater life cycle of salmonids: free passage is necessary during migr...

A numerical model is developed to simulate waves generated by high-speed vessels traveling at subcritical, transcritical and supercritical speeds in shallow water over water of varying depth. The waves in the far field are assumed to be weakly dispersive with wavelengths much longer than the water depth. The vertical profile of the flow field is obtained from a second-order Taylor series expans...

Subducting slabs carry water into the mantle and are a major gateway in the global geochemical water cycle. Fluid transport and release can be constrained with seismological data. Here we use joint active-source/local-earthquake seismic tomography to derive unprecedented constraints on multi-stage fluid release from subducting slow-spread oceanic lithosphere. We image the low P-wave velocity cr...

It is common in shallow seismic studies for the compressional-wave velocity in unconsolidated sediments to increase by a factor of four or more at the transition from dry or partial water saturation to full saturation. Under these conditions, conventional NMO velocity analysis fails and leads to large depth and layer thickness estimates if the Dix equation is assumed valid. Prestack depth migra...

We derived added mass and damping coefficients of a vertical floating circular cylinder due to surge motion in calm water of finite depth. This is done by deriving the velocity potential for the cylinder by considering two regions, namely, interior region and exterior region. The velocity potentials for these two regions are obtained by the method of separation of variables. The continuity of t...

A set of model equations for water wave propagation is derived by piecewise integration of the primitive equations of motion through N arbitrary layers. Within each layer, an independent velocity profile is determined. Depth-averaged and ‘‘extended’’ versions of the multi-layer model are presented and compared. With N separate velocity profiles, matched at the interfaces of the layers, the resu...

different construction materials with different roughness used to make circular weirs highly affect surface roughness and, in turn, flow hydraulics passing over these structures.  in the present research, numerous experiments under different hydraulic conditions were performed on a physical model to study the effects of roughness on flow hydraulics over a circular weir. the flow hydraulics incl...

abstract:dam construction providebenefits to local communities including hydropower generation and flood protection, but also harmsfish species by altering physical habitat andproviding pollution during the construction process. evaluating river reaches habitat suitability level mayknow how the habitat and which extentaffected by dams. this study used a systems analysis approach to preliminaril...