TUFLOW Remapping: Difference between revisions

With the release of TUFLOW 2020, the combination of Quadtree mesh and Sub-grid Sampling (SGS) method has offered a great flexibility for rapidly building flood modelmodels of varying resolution and buildingincreased topographic detail. Now a wide range of mesh sizesizes can be applied in a model based on the geographic feature and the area of interest in a project. Especially with the SGS method, cells and faces can be treated as 'partially wet', and the impact of the sub-grid scale geometry may be represented by cells with larger sizes. The example below shows that a Quadtree model with 10/20m cell size (right) can convey water as smoothly as a 2.5/5/10/20m model along the narrow and meandering gully line.<br>

On the other hand, the same model running without SGS methodapplied creates notably different results in the distance of water travelled and the area of inundation on the floodplain due to the poor geometrytopographic representation (one elevation per cell centre and cell face).<br>

These examples indicateshow how the mesh size sensitivities of a SGS modelsensitivity are significantly reduced, andif thususing SGS. Therefore, modellers arecan increasinglyconfidently usinguse a coarser mesh at areas far away from the area of interest without adversely affecting the results. However, this has also createcreated a challenge foron how to interpolatemap waterresults depthin outputareas at thoseof coarser cellsmesh. TheFor example, the images below showsshow that evenwhilst the 10/20m mesh and the 2.5/5/10/20m mesh SGS models produce similar water levellevels, the depth output is much 'smoother' in the 2.5/5/10/20m model withdue to the finer meshescomputational mesh. <br>