nyuuzyou/wikis huggingface dataset:
CSDMS 2015 annual meeting poster IrinaOvereem

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=Bringing earth surface processes simulations to large audiences=
Irina Overeem, University of Colorado, INSTAAR, CSDMS, Colorado, United States. irina.overeem@colorado.eduLauren Borkowski, University of Colorado, INSTAAR, CSDMS, Colorado, United States.Albert Kettner, University of Colorado, INSTAAR, CSDMS, Colorado, United States.Beth Russell, NOAA, Colorado, United States.Hilary Peddicord, NOAA, Colorado, United States.
Abstract:
The Community Surface Dynamics Modeling System has a strong mandate to share state-of-the-art earth surface process modeling results with large audiences. One of the possible platforms to reach audiences much beyond the science community is through museum displays. 
CSDMS has developed several model simulation datasets for the 'Science on a Sphere' system. 'Science on a Sphere' (SOS) consist of a large 4 ft diameter suspended globe on which global and regional simulations can be projected. SOS has been developed by NOAA and is now featured in over 100 locations worldwide, mostly in science museums and large research facilities. The SOS team at the Earth System Research Lab at NOAA estimates that >33 million people see these displays every year. In addition, the data catalogue features stand-alone downloadable movies and educational materials for teachers to use in their own class-rooms.
We contributed global simulations and datasets to the Science on a Sphere data catalogue. Examples include hydrological processes, coastal processes, and human interactions with the earth surface environment. 
Model simulations of a global hydrological and sediment transport model (WBM-SED) illustrate global river discharge patterns. WAVEWATCH III simulations have been specifically processed to show the impacts of hurricanes on ocean waves, with focus on hurricane Katrina and superstorm Sandy. A large world dataset of dams and reservoirs built over the last two centuries gives an impression of the profound influence of humans on water management. 
Visualizations are developed with Python scripts and comply to well-published data submission protocols of NOAA, mostly the scripts are unique for each specific model dataset. Datasets story boards and teacher follow-up materials associated with the simulations are developed to address common core science standards. CSDMS contributions aim to familiarize large audiences with the use of coupled numerical modeling as a tool to create insight and understanding of environmental processes, and aim to explicitly educate about models as a predictive tool. 
This presentations showcases CSDMS contributions to the Science on a Sphere data catalogue, shares insights on the workflow of getting simulations submitted to the SOS repository, and invites discussion and ideas from community members to develop new simulation datasets.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster JaapNienhuis

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=Wavelength selection of tidally reversing mega-ripples, field observations and comparison with numerical flow modeling=
Jaap Nienhuis, MIT-WHOI, Cambridge, Massachusetts, United States. jhn@mit.eduPeter Traykovski, WHOI, Woods Hole, United States.Katie Samuelson, MIT-WHOI, Cambridge, Massachusetts, United States.Taylor Perron, MIT, Cambridge, Massachusetts, United States.
Abstract:
Ripples formed by waves and tides are ubiquitous in coastal environments. Recently, significant advances have been made to understand the basic controls of waves on ripple geometry. However, due to the difficulty of making field measurements and the long timescales over which tidal velocity amplitudes change, our understanding of the controls of tides on ripples has thus far been restricted. An improved understanding of the wave and tidal controls on ripple geometry can improve models of coastal sediment transport, and, through study of ripples preserved in the sedimentary archive, help to determine paleoenvironmental conditions. In this study, we combine field observations of ripples with a detailed numerical flow model to investigate tidal controls on ripple wavelength.
Using almost two months of continuous observations of ripples obtained offshore of Martha’s Vineyard, we find a surprising dependence of ripple wavelength on tidal velocities. The wavelength during neap tide conditions is 0.4 m, when the maximum tidal velocities are 0.6 ms-1. At spring tide, with tidal currents of about 1 ms-1 close to the bed, the wavelength grows fivefold to more than 2 m. Because these ripples reverse every half-tidal cycle, and because the ripple wavelength is substantially longer than current ripples, we call these features tidally reversing mega-ripples. We have used a lattice Boltzmann model of turbulent flow across these features to study the influence of tidal currents on the flow separation zone downstream of the crest. For single ripples, flow velocities have a negligible influence on the separation vortices that develop. This is in agreement with flume observations and earlier numerical models of flow across bed forms. Surprisingly, however, when we place two ripples behind each other, we observe that vortices being shed off the upstream ripple increase the shear stress at the ripple crest downstream. We found that there exists a critical spacing at which the crest shear stress, and by extension, ripple migration rate, are equal for two subsequent ripples. This critical spacing coincides with our field observations of ripple wavelength during tidal conditions.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster KatelynWatson

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=Assessing the water balance of Dry Creek Experimental Watershed via an integrated modeling system=
Katelyn Watson, Boise State University, Idaho, United States. katelynwatson@u.boisestate.eduMiguel Aguayo, Boise State University, Idaho, United States.Alejandro Flores, Boise State University, Idaho, United States.
Abstract:
A significant limitation in many efforts to use physically based distributed hydrologic models, particularly in regions of complex terrain, is the complete lack of meteorologic forcing data at sufficiently fine spatial resolution approaching the correlation scales of meteorologic phenomena. Observational weather and climate data in mountainous regions are typically sparse, temporally discontinuous, and often poorly representative of the domain of interest. Increasingly, output from numerical weather prediction models is used as input to these hydrologic models. This approach, while computationally intensive, leads to internally and physically consistent environmental forcing variables distributed over the landscape at remote and ungauged areas. These data can then be used to feed sophisticated models of surface-subsurface hydrology. While an attractive alternative from the perspective of providing spatially and serially complete data, there are a number of unresolved issues associated with this “one-way” coupling of models. In order to explore some of the issues associated with this workflow, we are conducting a series of simulations to integrate an open-source, high spatial-resolution surface-subsurface hydrology model (ParFlow) with the Weather Research Forecasting (WRF) model. WRF is a sophisticated community regional weather and climate model that simulates environmental forcings required as input to the ParFlow model. We apply this modeling system to the Dry Creek Experimental Watershed located in the Boise foothills for the 2009 water year. Precipitation, snow and soil storage, and streamflows are evaluated using observational data from the experimental watershed to assess the performance of the modeling system. Performing these coupled model experiments in this high-relief experimental watershed will allow us to investigate not only the overall performance of the modeling system, but also the influence of varying the spatial resolution of WRF forcing information.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster KatherineRatliff

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=River-ocean interactions: Building a new morphodynamic delta model=
Katherine Ratliff, Duke University, North Carolina, United States. k.ratliff@duke.eduBrad Murray, Duke University, North Carolina, United States.
Abstract:
Deltas are among the most densely populated landscapes on earth, yet their morphology and inhabitants are increasingly susceptible to natural disasters, in part because of anthropogenic interactions with fluvial, coastal, and wetland processes. Humans have altered the natural course of many rivers via dams, channelization, and artificial levees, which can super-elevate the river above its floodplain. Rates of channel aggradation and backfilling increase as the relative sea-level rise rate (RSLRR) increases, potentially increasing the rate of flooding and avulsions. In order to investigate these effects on river and delta morphology, we have created a new river module based on steepest-decent methodology (Jerolmack and Paola, 2007) that incorporates floodplain deposition and avulsion processes. Preliminary results simulating anthropogenic manipulations of the river (e.g. inhibiting avulsions) show that the effects of artificial levees propagate hundreds of kilometers upstream. Results also indicate that avulsions reach farther upstream under higher RSLRR, and decreased subsidence rates result in more rapid avulsions. As a first step in developing a new 3D ecomorphodynamic delta model, we aim to couple this module with the 3D mode of Sedflux (Hutton and Syvitski, 2008). The new medium-detail model will be based on further model couplings, including vegetation, coastline, and human-dynamics modules. We plain to test, improve, and calibrate model and its parameterizations based on empirical data from the field and laboratory experiments.
Hutton, E, and J Syvitski (2008), Sedflux 2.0: An advanced process-response model that generates three-dimensional stratigraphy, Comput. Geosci. 34(10) 1319-1337.
Jerolmack, D, and C Paola (2007), Complexity in a cellular model of river avulsion, Geomorphology 91(3), 259-270.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster LaurenceLin

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=Modeling water and solute fluxes from terrestrial to aquatic ecosystems=
Laurence Lin, University of Alabama, Alabama, United States. lhlin@crimson.ua.eduSagy Cohen, University of Alabama Tuscaloosa Alabama, United States.Lisa Davis, University of Alabama Tuscaloosa Alabama, United States.
Abstract:
Existing watershed models for hydrology and solute exports include physically-based models, empirical models and their hybrids. These models has been developed for different watershed sizes and different research interests. The Regional Hydro-Ecological Simulation System (RHESSys) is one of the physically-based models that have been widely used. It was developed to couple hillslope hydrology and forest ecosystem in small / medium catchments. The Soil and Water Assessment Tool (SWAT) is a hybrid model that contains physically-based hydrology and empirical biology. It is mostly used for medium / large agriculture and urban-developed catchments. The Water Balance Model (WBM) is an empirical-oriented model that estimates discharge and suspended sediment export in large drainage basins. In this study, we evaluated these three types of watershed models for catchments with various sizes. The models were initialized using the elevation, climate, and vegetation data and calibrated using discharge monitored by USGS or Long Term Ecological Research (LTER). The simulated daily patterns of water and solute fluxes from terrestrial to aquatic ecosystem along the main channel were compared among the models. We aimed to recommend appropriate models for estimating water and nitrogen fluxes from terrestrial to aquatic ecosystems given a certain size of catchment.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster LiLi

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=T-Flux-PIHM: A Coupled Hydrological, Land Surface, and Reactive Transport Model for Hydrogeochemical Processes at the Watershed Scale=
Li Li, Penn State, University Park, Pennsylvania, United States.lili@eme.psu.eduChen Bao, Penn State, University Park, Pennsylvania, United States. Shi Yuning, Penn State, University Park, Pennsylvania, United States.
Abstract:
The close coupling of hydrological and geochemical processes at the watershed scale requires an integrated approach to examine their interactions and impacts. Here we present the first model that couple hydrological, land surface, and reactive transport processes, RT-Flux-PIHM, a new addition to the PIHM (Penn State Integrated Hydrological Model) family. The reactive transport module explicitly simulates geochemical reactions, including aqueous complexation, mineral dissolution and precipitation, redox reaction, gas dissolution-exsolution, adsorption and cation exchange. The reactive transport module was coupled to land surface and hydrological model in a sequential non-iterative manner with special treatment to minimize errors associated with operator splitting. This new integrated model is applied at the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) to study the controls on stream water and soil water chemistry. The temporal concentration evolution of non-reactive tracer chloride and weathering-derived magnesium in the stream water simulated in the model agreed well with measurements in 2009 with the maximum total bias less than 17% and 8%, respectively. The integration of processes in this model also helped to explain the temporal and spatial variation in pore water chloride and magnesium concentration within the watershed. Furthermore, parameter sensitivity analysis showed the van Genuchten parameter α and β, clay dissolution rates, groundwater influx rate, magnitude of annual precipitation, dissolution surface area of clays and the cation exchange site density have strong controls on the stream magnesium concentration. In summary, RT-Flux-PIHM provides a unique integration tool to understand the hydrogeochemical processes and responses to climatic, hydrological, and anthropogenic forcing at the water shed scale.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster LukeMcGuire

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=High resolution modeling of overland flow and sediment transport following wildfire=
Luke McGuire, USGS Golden, Colorado, United States. lmcguire@usgs.govJason Kean, USGS Golden, Colorado, United States. Dennis Staley, USGS Golden, Colorado, United States.Francis Rengers, USGS Golden, Colorado, United States.
Abstract:
Mountain watersheds that have been recently burned by wildfire often experience greater amounts of runoff, increased rates of sediment transport, and a significantly higher risk for debris flow generation relative to similar unburned areas. Previous work suggests that the redistribution of sediment within hillslope-channel systems by overland flow may play a key role in producing runoff-initiated debris flows, but the physical mechanisms by which water-dominated flows transition to a debris-flows are not well understood. In order to examine the connections between runoff, sediment transport, and debris flow initiation, we developed a numerical model that couples overland flow with sediment transport processes. We applied the model to study erosion from a single rainfall event that produced numerous debris flows within a small, recently burned drainage basin in the San Gabriel Mountains, CA. Input data for the numerical model was constrained by rain gauges, stage measurements at the basin outlet, soil moisture sensors, and soil particle size distribution analyses. Pre- and post-storm basin topography was obtained using high-resolution terrestrial laser scanner data. Numerical model results are quantitatively compared to post-event terrestrial laser scanner data and stage measurements recorded during the event. Our preliminary results show that the magnitude and spatial pattern of model-predicted erosion/deposition compare favorably with the measured topographic change throughout the study area. Additionally, the model predictions suggest that rain splash induced sediment transport was the dominant form of erosion throughout much of the watershed. Based on numerical model predictions, the failure of sediment piles that were generated by preferential deposition within the channel system likely contributed to repeated debris flow initiation throughout the event.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster MahdadTalebpour

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=Secondary current simulations in open channels with different bed roughness configurations=
Mahdad Talebpour, Penn State University State College Pennsylvania, United States. mxt982@psu.edu 
Abstract:
Secondary current in open channels have been long recognized as an important mechanism to alter the path of sediment particle motion and consequently change the river and land surface evolution. Researchers have identified two different kinds of secondary current: the first kind due to curvature in a river bend and the second kind due to turbulence anisotropy. This paper deals with the second kind in a straight open channel. Despite the continuous research effort, the mechanism is still not fully understood. One of the intriguing features is that in natural channels, the co-evolution of the river and the bed, and more importantly the differential transport of sediment mixture, often result in the the non-homogeneous distribution of roughness on the channel bottom. The mutual influence of secondary current and bed roughness is of great interest to geologists and hydraulic engineering researchers. This paper aims to map the details of the flow field using a computational model equipped with a new nonlinear $k-\omega$ model. This nonlinear model is designed to take into account the anisotropy of turbulence and since it is written in $k-\omega$ formulation, it can be integrated all the way to the wall. Low-Reynolds number (LRN) form of the model also makes it unnecessary to use a wall-function, which breaks down in many cases. The roughness effect on the turbulence is through a simple relationship for the $\omega$ boundary condition. The aim of this work is first to test the model in the context of riverine flows, and second to calibrate the model so it can be used with roughness patches. It is found the new turbulence model is capable to generate and maintain the secondary current. This paper will present the calibration result against classic experimental data. The results suggest the model is somewhat sensitive to the boundary condition on the bottom and less so to the free surface. As speculated in the many theories and observed in experiments, the simulation confirms that the secondary current above a non-homogeneous bed is mainly driven by the current generation near the bed and then a cellular motion is induced by the virtue of continuity. In other words, the anisotropy of turbulence near the free surface only plays a secondary role. The calibrated simulation results are further used for more detailed analysis on the momentum and vorticity budget.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.
CSDMS 2015 annual meeting poster ManLiang

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<FONT style="FONT-SIZE:10pt" color="#ffffff">Presentation provided during CSDMS annual meeting 2015</font>
=Reduced-Complexity Model (RCM) for River Delta Formation – Model Assessment and Application=
Man Liang, University of Texas at Austin, Texas, United States. manliang@utexas.eduCorey Van Dyk, University of Texas at Austin, Texas, United States.Paola Passalacqua, University of Texas at Austin, Texas, United States.Wonsuck Kim, University of Texas at Austin, Texas, United States.
Abstract:
Understanding deltaic channel dynamics is essential to acquiring knowledge on how deltas respond to environmental changes, as channels control the distribution of water, sediment, and nutrients. In recent years a variety of models have been developed, which provide the basis for the development of a quantitative framework to study deltaic channel dynamics. However, robust metrics are needed to effectively evaluate numerical models and extract relevant information. 
In this work we use existing and new metrics, developed in the context of river delta formation, to assess the morphodynamic results of DeltaRCM, a reduced complexity model for delta formation and evolution. Model results are compared to theoretical predictions, field observations and physical experiments. We show that DeltaRCM captures: 1) the geometric growth characteristics of river-dominated deltas such as the fractal growth of channel network, 2) the temporal dynamics of channels at the level of autogenic timescales such as fluctuations in the fraction of wetted surface and loss of channel overlap with time. We also demonstrate how to use a new metric for subsurface structure, sedimentograph, to explore the radially-averaged distribution of coarse and fine sediment. Furthermore, we investigate how deltaic distributary channel networks respond to subsidence and sea-level rise. The results show that without coastal processes such as waves and tides, distributary channel networks exhibit intensified branching in response to continuous relative sea-level rise.
* Please acknowledge the original contributors when you are using this material. If there are any copyright issues, please let us know and we will respond as soon as possible.