Dynamics of Sandwaves under Combined Wave - Current Forcing and Mine Burial Processes, and Instrumentation for Measuring Nearshore Morphologic Change and Hydrodynamic Forcing
نویسندگان
چکیده
Our long terms goals are to understand sediment transport processes, the relevant physical forcing processes and the resulting morphologic evolution of river mouths and tidal inlets and shoals. Specific goals include understanding bedform characteristics (ripple to sandwave and sandbar scale) in relation to wave-and current-forced mean and turbulent flow. OBJECTIVES 1. Measure the currents, hydrodynamic boundary layer processes, sediment-transport processes and bedform evolution in energetic ebb-tidal shoal environments, where nonlinear interactions between waves and tidal currents are critically important to the sediment transport and the morphological response to changing forcing conditions. 2. Determine the mechanism responsible for the burial of mine-like objects in regions of active bedforms. 3. Develop instrumentation to make essential measurements for the above objectives. This includes autonomous and manned survey vessels with a carrier phase GPS and Doppler profilers for resolution of near bed turbulence and flow. APPROACH In order to measure the processes responsible for inlet morphologic change we conducted repeat bathymetric and hydrographic surveys along with in-situ time series measurements of water velocity (waves and currents), sediment transport (both suspended load and bedload via bedforms migration) and bed elevation. In 2012, we focused on measurements in New River Inlet, NC as part of the first phase of the rivers and inlets (RIVET) DRI. Our approach to this project consisted of combined spatial shipboard and AUV surveys with in-situ measurements from seafloor mounted frames (quadpods). The spatial surveys were conducted with a small boat with an ADCP, and motorized kayak with sidescan, echosounder and post-processing kinetic (PPK) GPS system and a REMUS-100 AUV with an ADCP, sidescan and PPK-GPS system. Grab samples and CTDs were also collected from the small
منابع مشابه
’ Dynamics of Sandwaves under Combined Wave - Current Forcing and Mine Burial Processes ’ , and ’ RIVET
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