Model:Kirwan marsh model
From CSDMS
Kirwan marsh model
Introduction
History
Papers
Kirwan marsh model Questionnaire
Contact Information
| Model: | Kirwan marsh model |
| Contact person: | Matthew Kirwan (Model developer) |
| Institute: | University of Virginia |
| City: | Charlottesville, Virginia |
| Country: | USA |
| Email: | mkirwan@usgs.gov |
| 2nd person involved: | Brad Murray (Model developer) |
| 3rd person involved: |
Model description
| Model type: | Single model for the coastal domain. |
| Description: | Spatially explicit model of the development and evolution of salt marshes, including vegetation influenced accretion and hydrodynamic determined channel erosion. |
Technical information
| Supported platforms: | Linux |
| Programming language: | C |
| Model development started at: | 2003 and development still takes place. |
| To what degree will the model become available: | From case by case basis from author |
| Current license type: | GPL v2 |
| Memory requirements: | -- |
| Typical run time: | hours to days |
Input / Output description
| Input parameters: | Does not require any input data, but if desired, model can run from files describing sea level and/or the elevations of an existing marsh. |
| Input format: | ASCII |
| Output parameters: | Elevation, Biomass, Accretion Rate, Erosion Rate, and other characteristics of every cell in domain. Also outputs spatially averaged statistics. |
| Output format: | ASCII |
| Post-processing software (if needed): | No |
| Visualization software (if needed): | Yes, Matlab |
Process description
| Processes represented by model: | The model calculates changes in elevation and vegetation growth for a hypothetical salt marsh. In each cell, elevation change is calculated as the difference between accretion and erosion. Accretion rates are a function of inundation depth, vegetation growth, and suspended sediment concentration. Water routed according to Rinaldo et al. (1999) scheme. Erosion rates calculated according to excess sheer stress. Channels widen according to a diffusion-like routine where downslope transport is inversely proportional to vegetation. Vegetation grows according to Morris et al. (2002) where biomass is proportional to inundation depth up until an optimum depth. Episodic vegetation disturbance is simulated by removing vegetation from randomly selected cells (Kirwan et al., 2008). Another version of the model treats wave erosion in a simplistic manner (Kirwan and Murray, 2008). |
| Key physical parameters & equations: | Key parameters include the rate of sea level rise, suspended sediment concentration, tidal range (which controls vegetation distribution), critical shear stress for sediment erosion, and the period of time that erosion takes place during each tidal cycle. Parameters controlling the growth pattern of vegetation can easily be modified. |
| Length scale & resolution constraints: | Domain size is 3 km by 3 km, grid cell is 5 m by 5m. |
| Time scale & resolution constraints: | The model explicitly runs on an individual tidal cycle time step, which we scale up to 2 months. But, results most meaningful at timescales greater than a couple years. |
| Numerical limitations and issues : | -- |
Testing
| Available calibration data sets: | Biomass productivity and marsh accretion rates from 1984-present, described in Morris et al. (2002). |
| Available test data sets: | A couple high resolution Pb210 curves that span ~100 years are currently being constructed and used to test model. |
| Ideal data for testing: | Long term, high resolution (annual to couple years) datasets of marsh accretion. Similar time series of channel characteristics would be useful. |
User groups
| Currently or plans for collaborating with: | Yes |
Documentation
| Key papers of the model: |
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| Is there a manual available: | no |
| Model website if any: | -- |
Additional comments
| Comments: | -- |
