Model:AquaTellUs
From CSDMS
AquaTellUs
Introduction
History
Papers
AquaTellUs Questionnaire
Contact Information
| Model: | AquaTellUs |
| Contact person: | Irina Overeem |
| Institute: | CSDMS, INSTAAR, University of Colorado |
| City: | Boulder, CO |
| Country: | USA |
| Email: | overeem@colorado.edu |
| 2nd person involved: | -- |
| 3rd person involved: | -- |
Model Description
| Model type: | Modular model for the terrestrial and coastal domain. |
| Description: | AquaTellUs models fluvial-dominated delta sedimentation. AquaTellUS uses a nested model approach; a 2D longitudinal profiles, embedded as a dynamical flowpath in a 3D grid-based space. A main channel belt is modeled as a 2D longitudinal profile that responds dynamically to changes in discharge, sediment load and sea level. Sediment flux is described by separate erosion and sedimentation components. Multiple grain-size classes are independently tracked. Erosion flux depends on discharge and slope, similar to process descriptions used in hill-slope models and is independent of grain-size. Offshore, where we assume unconfined flow, the erosion capacity decreases with increasing water depth. The erosion flux is a proxy for gravity flows in submarine channels close to the coast and for down-slope diffusion over the entire slope due to waves, tides and creep. Erosion is restricted to the main flowpath. This appears to be valid for the river-channel belt, but underestimates the spatial extent and variability of marine erosion processes. Deposition flux depends on the stream velocity and on a travel-distance factor, which depends on grain size (i.e. settling velocity). The travel-distance factor is different in the fluvial and marine domains, which results in a sharp increase of the settling rate at the river mouth, mimicking bedload dumping. Dynamic boundary conditions such as climatic changes over time are incorporated by increasing or decreasing discharge and sediment load for each time step.! |
Technical information
| Supported platforms: | Windows |
| Programming language: | C |
| Model development started at: | 1997 and development still takes place. |
| To what degree will the model become available: | Source code will be available |
| Current license type: | -- |
| Memory requirements: | High |
| Typical run time: | hours |
Input / Output description
| Input parameters: | Simulation time (t) and time step (dt), Initial grid size and slope, Incoming discharge and sediment load (t), Sea level (t), no of grain size classes, grain size distribution, grain size.
Sediment transport coeficients |
| Input format: | ASCII |
| Output parameters: | Grid of deposition of different grains over time. The model generates postscript files of stratigraphic sections. |
| Output format: | ASCII |
| Post-processing software (if needed): | Grid plotting software, Postscript plotting software |
| Visualization software (if needed): | Yes, Matlab, SURFER/GRAPHER |
Process description
| Processes represented by model: | Fluvial erosion and depositions, lateral deposition across the floodplain, plume deposition in marine domain. |
| Key physical parameters & equations: | See references. |
| Length scale & resolution constraints: | The model domain starts in the fluvial floodplain, the main river channel is considered an incoming boundary condition. Gridcells are typically averaged over 100's meters to 1000's of meters. Tests ran with grids of 150 by 150 km. |
| Time scale & resolution constraints: | Developed as a stratigraphic model, approach is event-based. Intended time scale ranges from several decades to Holocene (10-10.000yrs). |
| Numerical limitations and issues : | Code is research grade |
Testing
| Available calibration data sets: | Not readily available; theoretical experiments are available as examples. |
| Available test data sets: | AquaTellUs was originally developed for simulation of the fluvial-dominated Volga delta. The 2D experiments are still available and can be used as a test data set. |
| Ideal data for testing: | Boundary conditions like river discharge and sediment loads, input grainsize data, sea level history. Floodplain and deltaic sedimentation rates and grainsize data. |
User groups
| Currently or plans for collaborating with: | Intent to use for braided Arctic fan deltas. CSDMS group is currently working on floodplain processes and bedload distribution patterns based on RS data. |
Documentation
| Key papers of the model: |
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| Is there a manual available: | no |
| Model website if any: | no |
Additional comments
| Comments: | Code is research grade and needs to be refractored before submission to CSDMS. |
