nyuuzyou/wikis huggingface dataset:
CSDMS 2011 annual meeting poster Barry Eakins

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=A new way to access digital elevation models=
Barry Eakins, University of Colorado at Boulder Boulder Colorado, United States. barry.eakins@colorado.eduMatthew Love, University of Colorado at Boulder Boulder Colorado, United States. matthew.love@colorado.edu
Abstract:
NOAA’s National Geophysical Data Center (NGDC) develops and publicly distributes a wide variety of topographic and integrated bathymetric-topographic digital elevation models (DEMs), ranging from the global ETOPO1 and GLOBE, to high-resolution (~10-m cell size) coastal DEMs to support NOAA’s tsunami forecast and warning efforts. We have developed a prototype online tool, using an underlying THREDDs catalog, to view and extract the square-cell models in their native resolution and datums, subset by user extents, and output in netCDF, geotiff, xyz, or ESRI Arc ASCII formats. We have also implemented a command-line get request that bypasses the browser interface. Current models include the 1-minute ETOPO1, 30-second GLOBE topography, the 3 arc-second U.S. Coastal Relief Model (CRM) and Great Lakes Bathymetry, and the 24 arc-second Southern Alaska CRM. In the future, we will be expanding the catalog to include all of NGDC’s public DEMs, and are investigating ways to in-fill gaps between higher-resolution DEMs with data from coarser models. 
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CSDMS 2011 annual meeting poster Carl Friedrichs

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=Results of the US IOOS Testbed for Comparison of Hydrodynamic Models of the Chesapeake Bay=
Carl Friedrichs, VIMS Gloucester Point Virginia, USA. cfried@vims.eduAaron Bever, VIMS , USA. Marjorie Friedrichs, VIMS , USA. Malcolm Scully, ODU , USA.Estuarine Hypoxia Testbed Team , , USA.
Abstract:
Through funding provided by the US Integrated Ocean Observing System, five open source 3-D hydrodynamic models for Chesapeake Bay have been compared to each other and to EPA monitoring data for hindcasts of the years 2004 and 2005. The aim of this project is to provide NOAA, EPA, other government agencies, and the larger modeling community meaningful guidance on the relative accuracy, efficiency, complexity and likely utility for federal operational and scenario modeling of a suite of community models available for simulating hydrodynamics and oxygen dynamics in Chesapeake Bay. The focus of the present paper is on the hydrodynamic comparison of:
# the ChesROMS model (http://ches.communitymodeling.org/models/ChesROMS/index.php)
# the CBOFS2 model (http://cedb.asce.org/cgi/WWWdisplay.cgi?265616)
# the CH3D model (http://www.chesapeakebay.net/publication.aspx?publicationid=55318)
# the EFDC model 
# the UMCES ROMS model
These models represent a range of resolutions (from ~5,000 to ~50,000 wetted cells). The models do similarly well in reproducing 3-D, time-dependent temperature fields. Bottom salinity is significantly improved with increases in horizontal resolution that better capture the structure of narrow, deep channels. Seasonal variation in density stratification is surprisingly difficult for all the models to capture well, and density stratification is not found to be especially sensitive to horizontal or vertical resolution within the range of resolutions considered. The hydrodynamics in general are not particularly sensitive to refinements in offshore climatological forcing, nor to refinements in riverine input, nor to refinements in spatial resolution of wind forcing. Lateral and longitudinal advection is sensitive, however, to seasonal changes in wind velocity and direction, suggesting that typical seasonal changes in wind forcing may be more important than seasonal changes in local stratification in controlling transfer of oxygen to deep channels susceptible to hypoxia. 
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CSDMS 2011 annual meeting poster Caroline Le Bouteiller

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=A velocity-dependant friction law for flexible vegetation in a 2D hydrodynamic model=
Caroline Le Bouteiller, Northwest Hydraulic Consultants Vancouver, B.C. NO STATE, Canada. caroline.le-bouteiller@m4x.org
Abstract:
The tidal flats of Roberts Bank in British Columbia, Canada contain large areas of the intertidal zone that are vegetated with eelgrass (Zostera Marina and Zostera Japonica). This vegetation has a variable influence on the flow of tidal waters passing over the tidal flats, which we aim to describe in a large-scale 2D hydrodynamic model.
Vegetation on the surface of the tidal flats causes an increase in the roughness that modifies the flow properties. For submerged vegetation, this roughness is most strongly related to the height of the plants in the water; however, for very flexible plants such as eelgrass, the plant height changes with flow velocity since the plants bend with the currents. The roughness is therefore dependent both on flow depth and flow velocity.
Existing studies concerning the effect of flexible vegetation on flow are mostly focused on the small-scale properties of the velocity and turbulence profiles. Such results cannot be directly incorporated into 2D hydrodynamic models. 3D hydrodynamic modeling is computationally demanding and is therefore less appropriate for large-scale studies and engineering applications over large areas. In order to resolve this computational challenge we developed an integrated formulation of the effects of flexible vegetation on the flow, with the following approach: The roughness is represented through an equivalent Manning’s coefficient, which depends on both the water depth and the flow velocity.
Simulations are performed with the Telemac2d model, which has been modified to incorporate the velocity-dependent friction law. Preliminary results show that the proposed law is able to account for qualitative modifications in the tidal flow. In particular, the simulation provides an asymmetric flow pattern that correctly predicts the slower ebb velocities as compared to flood velocities, as observed in the field. 
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CSDMS 2011 annual meeting poster Chris Jenkins

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=Temporal-spatial features of Biologically-Based Carbonate Modeling=
Chris Jenkins, INSTAAR boulder Colorado, USA. chris.jenkins@colorado.edu
Abstract:
A new class of models based on population ecology, nutrient-geochemistry, and sedimentology is able to simulate carbonate accretion in reef and shelf environments. Unlike previous models for carbonates, they produce very detailed simulations of facies variabilities in space and time. With adjustments to the model runs the range of variabilities can be explored and described statistically. We look at comparisons of the statistics from the models and in outcrops/drillcores of carbonate rocks and ecological transects of present-day seabed areas. 
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CSDMS 2011 annual meeting poster Chunshui Yu

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=Depth-Averaged Two Dimensional Model Using Cartesian Cut-Cell Approach=
Chunshui Yu, Univ. of Arizona Tucson Arizona, USA. Jennifer Duan, Univ. of Arizona Tucson Arizona, USA. gduan@email.arizona.edu
Abstract:
A two-dimensional numerical model was developed for simulating free surface flow. The model is based on the solutions of two-dimensional depth averaged Navier-Stokes equations. A finite volume method is applied such that mass conservation is satisfied both locally and globally. The model adopted the two-step, high resolution MUSCL-Hancock scheme. This Godunov type scheme is used together with the approximate Riemann solver. The boundary cells are treated as cut-cells in order to accommodate arbitrarily geometries of natural rivers. There are sixteen types of cut-cells depending on the slope of the boundary intersection with the cell. A cell merging technique is incorporated in the model that combines small cells with neighboring cells to create a larger cell, helps keeping the CFL condition. The cut-cells approach permits a fully boundary-fitted mesh without implementing a complex mesh generation procedure for irregular geometries. The model is verified by several laboratory experiments including unsteady flow passing through cylindrical piers and dam break flow in a rectangular channel. The model is also applied to simulate a 100-year flood event occurred at the Huron Island reach of the Mississippi River, where flow paths in the island formed a complex channel network as flood propagates. 
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CSDMS 2011 annual meeting poster Courtney Harris

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=Using a three-dimensional coupled sediment – hydrodynamic model to explore feedbacks between erodibility and sediment trapping in a partially mixed estuary, York River, VA=
Courtney Harris, Virginia Institute of Marine Science Gloucester Point Virginia, USA. ckharris@vims.eduJ. Paul Rinehimer, Applied Physics Lab, University of Washington Seattle Washington, USA.Christopher Sherwood, US Geological Survey Woods Hole Massachusetts, USA. 
Abstract:
The MUltiDisciplinary Benthic Exchange Dynamics (MUDBED) program explored the impact of physical and biological processes on turbidity and sediment properties in a muddy estuary. Hydrodynamics, settling velocity, and erodibility influence suspended sediment concentrations. In turn, flux convergence and divergence modify suspended sediment and seabed properties, thereby impacting Estuarine Turbidity Maxima (ETM). In partially mixed estuaries like the York River, VA variations in stratification and sediment trapping respond to tides, discharge, and winds, and produce a Secondary Turbidity Maxima (STM) that appears seasonally downstream of the main ETM.
A hydrodynamic and sediment-transport model of the York River was developed to examine feedbacks between sediment flux convergence, erodibility, and settling velocity. The Regional Ocean Modeling System (ROMS) was coupled to the Community Sediment Transport Modeling System (CSTMS). The model included bed consolidation by representing critical shear stress for erosion as increasing with depth in the bed and with time since deposition. Multiple grain types were used having settling velocities from 0.1 – 2.5 mm/s. Calculations of turbidity and erodibility showed similar patterns to observations and exhibited high spatial variability in both the along and across channel directions. Sediment trapping in the model led to the development of an erodible pool of sediment near the observed STM. Enhanced erodibility elevated suspended sediment concentrations in that area for some time after sediment convergence processes diminished. This poster will explore the behavior of the model and evaluate the use of the simplified bed consolidation model within a full three-dimensional numerical model. 
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CSDMS 2011 annual meeting poster Donald Potts

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=A Knowledge Base Supporting Biologically-Based Carbonate Modeling=
Donald Potts, University of California, Santa Cruz Santa Cruz California, USA. potts@biology.ucsc.eduChris Jenkins, INSTAAR Boulder Colorado, USA. chris.jenkins@colorado.eduPeter Burgess, Royal Holloway, University of London London NO STATE, UK. burgess@hotmail.comRachel Fabian, University of California, Santa Cruz Santa Cruz California, USA. rfabian@ucsc.eduHelen O'Brien, University of California, Santa Cruz Santa Cruz California, USA. obrien@biology.ucsc.edu
Abstract:
Marine carbonates are created by the metabolism, growth, death and skeletal accumulations of a diverse array of benthic organisms (e.g. corals, bryozoa, molluscs, foraminifera, calcareous algae, and micro-organisms), but carbonate accretion requires a positive net balance among biological growth processes, processes of biological erosion (mainly by fishes, urchins, polychaetes, molluscs, sponges, algae and micro-organisms), and physical processes of destruction, suspension, transport, deposition and cementation. We are creating a knowledge base (KB) containing empirical quantitative data about individual, population and community properties of major calcifying and bio-eroding species to capture the ecological variation inherent in all biological processes, both spatial (e.g. latitude, longitude, habitat, climate, oceanography, depth) and temporal (e.g. diurnal, seasonal, interannual). The KB will provide realistic values for input to a “virtual aquarium” of characteristic organisms at the center of biologically-based carbonate models describing the initiation, growth and maturation through ecological to geological timescales of such formations as shallow and deep-sea coral reefs, Halimeda beds, bryozoan reefs, and maerl deposits. 
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CSDMS 2011 annual meeting poster Eunseo Choi

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=Landslide rupture and length-depth scaling=
Eunseo Choi, Lamont-Doherty Earth Observatory Palisades New York, USA. echoi@ldeo.columbia.edu
Abstract:
Landslides are often assumed to exhibit self-similarity in their failure geometry, and thus a linear scaling between slip depth and rupture length. This assumption has important implications for the prediction of large landslide volumes and for the estimation of erosion budgets by mass-wasting. Nevertheless, some field data indicate a break from self-similarity and imply that, in some circumstances, landslide depth may scale non-linearly with length. Here we test the simple scaling hypothesis by numerical experiment. Modeling is performed with SNAC (StGermaiN Analysis of Continua), a 3D community code originally designed to model viscoelastoplastic deformation on a crustal scale and newly adapted to treating hillslope failure. SNAC employs a parallelized, Lagrangian, explicit finite-difference scheme and dynamic relaxation to solve static, quasi-static and steady-state problems. Landslide rupture is treated as emergent shear localization under strain-weakening Mohr-Coulomb plasticity. We model only the initial slip and early motion of a landslide; granular flow during the runout phase is not considered. A set of 2+1D simulations of failures spanning lengths of 50–400m suffice to vindicate cross-sectional self-similarity—absent any dominant depth scale or trend in the variation of cohesion—and a depth-length ratio of 11–15% is recorded. An interesting by-product of the choice of experimental geometry is some unanticipated complexity in the evolution of the slip plane. Failure initiates at the toe, propagates upslope, and asymptotically parallels the planar upper boundary. However, a connected failure surface is only achieved once a secondary rupture has propagated downwards into this slip plane from the upper breakaway zone. The broader outcome of our numerical experiments is a demonstration of how 3D continuum modeling of soil and rock-slope failure, and the study of their rich behavior, is now feasible using non-commercial code on supercomputing platforms.
Simulated landslide geometries and model plastic strain (colors): (a) L = 50 m, (b) L = 100 m, (c) L = 200 m, (d) L = 400 m.
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CSDMS 2011 annual meeting poster Fei Xing

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=Exploring river-wave dominated delta evolution applying a model-coupling approach=
Fei Xing, CSDMS, INSTAAR, University of Colorado Boulder Colorado, USA. Fei.Xing@colorado.eduAlbert Kettner, CSDMS - INSTAAR, Univ. of Colorado Boulder Colorado, USA. kettner@colorado.eduAndrew Ashton, Woods Hole Oceanographic institution Woods Hole Massachusetts, USA. aashton@whoi.eduEric Hutton, CSDMS - INSTAAR, Univ. of Colorado Boulder Colorado, USA. eric.hutton@colorado.eduJames Syvitski, CSDMS - INSTAAR, Univ. of Colorado Boulder Colorado, USA. james.syvitski@colorado.edu
Abstract:
Deltas are the important interface between continents and oceans, providing home to over half a billion people. The unique environment supports a wide variety of diverse ecosystems and is highly susceptible to a broad spectrum of interacting forces. Therefore it is critical to understand its current and future changes, especially against the background of climate change and human impact, something that could be explored by studying its historical evolution process. Delta evolution is mainly governed by: a) sediment load supply from its contributing river, and 2) ocean dynamics (e.g. waves, tides). Fluvial sediment supply to a delta fluctuates over time either e.g. due to shifts in climate or, on shorter time scales, due to human interference (e.g. deforestation which could increase sediment supply or the emplacement of dams and reservoirs that reduces the sediment supply). How does this affect the morphology of a delta? Waves interact on deltas by dispersing fluvial sediment, reshaping its shoreline, how will it be illustrated in delta’s shape and morphology?
To study this, we explored hypothetical delta evolution scenarios given the following boundary conditions: a medium size upstream drainage basin (~80,000km2) with, as base case, a typical Mediterranean climate. The analysis is done through coupling two numerical models, HydroTrend and CEM. HydroTrend, a climate-driven hydrological transport model, is applied to replicate freshwater and sediment flux to the delta, and subsequently a coastline evolution model (CEM) is applied to simulate the according changes in the delta’s coastline morphology. A component-modeling tool (CMT) developed by CSDMS, is used to couple the models for this study. Several scenarios are considered that take into account: 1) stepwise increasing fluvial sediment supply, to the delta and 2) the release time of these stepwise sediment increases by changing the storm intensity for periods of time.
Preliminary model experiments will be presented demonstrating: 1) the capability of the CMT to couple models that represent different process domains and were developed and designed independently (i.e. without the intentions of such coupling), 2) the impact of changes in fluvial sediment on deltas.
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CSDMS 2011 annual meeting poster Ilgar Safak

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2011</font>
=Modeling sediment transport processes and residence times in the shallow coastal bay complex of the Virginia Coast Reserve=
Ilgar Safak, University of Virginia, Charlottesville Virginia, USA. ilgar@virginia.eduPatricia Wiberg, University of Virginia, Charlottesville Virginia, USA. pw3c@virginia.edu
Abstract:
Patterns of sediment transport and particle residence times influence the morphology and ecology of shallow coastal bays in important ways. The Virginia Coast Reserve (VCR), a barrier island-lagoon-marsh system on the Eastern Shore of Virginia, is typical of many shallow coastal bay complexes that lack a significant fluvial source of freshwater and sediment. Sediment redistribution within the bays in response to storms and sea-level rise, together with the dynamics of marsh and lagoon-bottom plants, largely governs the morphological evolution of this system. There are also important feedbacks between sediment and ecosystem dynamics. This is particularly true in the VCR, which is relatively unaffected by human activities. As a step towards evaluating the impact of hydrodynamics on sediment and ecological processes in the VCR, we employ a single unified model that accounts for circulation, surface waves, wave-current interaction, and sediment processes. This three-dimensional unstructured grid finite-volume coastal ocean model (FVCOM) is validated with field observations of wind- and tide-induced water flow (water level and current velocities) in Hog Island Bay, centrally located within the VCR. We present here the resulting patterns of sediment transport and particle residence times over event and seasonal time scales. Water and particle exchange within the VCR and between the VCR and the ocean is examined with the Lagrangian particle-tracking module in FVCOM. We focus on 3 bays with strongly varying bathymetry and coastline geometry, which are also located along a gradient of nitrogen input to the system. The results indicate that residence time of particles within the system vary greatly depending on the location of particle release, bay morphology, and wind conditions. The implications for morphologic evolution and ecosystem response to climate and land-use changes are evaluated. 
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