TUFLOW 2D Cell Size Selection: Difference between revisions
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== Test Case 1 - Discussion ==
The graphed results indicate convergence is observed for all cases with a cell resolution equal to or less than 100m. The grid figures presented to the right of the graphs suggest the 100m cell resolution case has approximately (4) four cells laterally across the valley that the dam break flow is contained within. Although the 400-600m wide valley isn't a traditional creek or river channel, the scale of flow associated with the dam break means the valley is behaving like one. Minor topographic features within the valley are too small to have a significant impact on the flood behaviour for flow conditions of this large magnitude. This result trend is consistent with the Australian Rainfall and Runoff (ARR) cell size recommendation for the flow in a channel, "In order to adequately resolve flow in a channel it is desirable to provide at least 5 grid/mesh elements laterally across the channel".
Simulation time can influence model resolution selection. This is not the case in this situation. All models have run in under 5 minutes using TUFLOW HPC's GPU hardware module.
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Since simulation time is not a limiting factor in this case selection of cell size only needs to consider the result accuracy and the number of simulations needed.
* What is appropriate in terms of accuracy is influenced by the intended use of the model. For example, if lot scale assessment of inundation risk is required, selection of the 10m cell size may be appropriate. Alternatively, if the model is only intended to inform broad-scale risk, the 50m or 100m cell size may be sufficient.
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= Test Case 2 - Urbanised Catchment =
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