Property:Describe numerical limitations
From CSDMS
This is a property of type Text.
I
If you will be processing very large landscapes then you may need to configure PETSc with the --with-64-bit-indices option. +
M
Implicit code. Very stable. Very efficient +
T
In general, Matlab stores all data in the main memory. Manageable grid size will depend on your available RAM. For conveniently working with grids with ~5000x5000 rows and columns, a 4Gb of RAM will likely be sufficient. +
C
R
C
Matlab may max out memory if drainage basin is too large. Since this is a simplified landscape with wrap-around boundary conditions, one workaround is to do numerous smaller runs and add the output. +
M
Maximum timestep must be determined by trial. +
S
Model Assumptions
* Mild bottom slope and negligible wave reflection
* Spatially homogeneous offshore wave conditions
* Steady-state waves, currents, and winds
* Linear refraction and shoaling
* Depth-uniform current
* Bottom friction is neglected +
T
Model Limitations
* TOPMODEL only simulates watershed hydrology, although studies have been conducted to modify it to
simulate water quality dynamics.
* TOPMODEL can be applied most accurately to watersheds that do not suffer from excessively long dry
periods and have shallow homogeneous soils and moderate topography.
* Model results are sensitive to grid size, and grid size <=50 m is recommended. +
I
B
Model is solved implicitly, but can become inaccurate at very large (~1000 year) timesteps. When baselevel forcing is mild and block effects are significant, slope-inversion instabilities can develop. The model catches these and will not continue running. +
E
Model limitations are related to the use of the goal seek function in excel to find the solution. +
P
Model should never be numerically unstable but its behavior depends on ratios of various parameters. If the model seems to not be "doing anything", look at the parameter initialization functions in deltaRCM_tools.py +
M
Model slows down as layers are added making long runs (>2000 years) impractical. +
H
Model works well for resistant layer dips between 10 and 80 degrees. End members will work, but domain setup must be altered. +
D
Most Dakota analysis techniques require multiple iterations of a model to explore a requested parameter space, so an experiment created with Dakotathon can take a long time to run and produce a lot of model output. +
C
Most of the heavy lifting algorithms are implicit, thus numerically stable +
H
N
S
