Changeset 2729 for documentation/user_manual/anuga_user_manual.tex

Timestamp:

Apr 19, 2006, 6:15:06 PM (18 years ago)

Author:

sexton

Message:

updates to user_manual (modelling questions)

File:

• documentation/user_manual/anuga_user_manual.tex (modified) (1 diff)

documentation/user_manual/anuga_user_manual.tex

@@ -1834 +1834 @@
 \subsubsection{Which diagnostics are available to troubleshoot a simulation?}
 
+\subsubsection{How do I use a DEM in my simulation?}
+You use \code{dem2pts} to convert your DEM to the required .pts format. This .pts file is then called When setting the elevation data to the mesh
+in \code{domain.set_quantity}
+
+\subsubsection{What sort of DEM resolution should I use?}
+Try and work with the "best" you have available. Onshore DEMs are typically available in 25m, 100m and 250m grids. Note, offshore data is often sparse,
+or non-existant.
+
+\subsubsection{What sort of mesh resolution should I use?}
+The mesh resolution should be commensurate with your DEM - it does not make sense to put in place a mesh which is finer than your DEM. As an example, 
+if your DEM is on a 25m grid, then the cell resolution should be of the order of 315$m^2$ (this represents half the area of the square grid). Ideally,
+you need a fine mesh over regions where the DEM changes rapidly, and other areas of significant interest, such as the coast. 
+
+\subsubsection{How often should I store the output?}
+This will depend on what you are trying to answer with your model and how much memory you have available on your machine. If you need
+to look in detail at the evolution, then you will need to balance against your storage requirements and the duration of the simulation. 
+If the sww file exceeds 1Gb, another sww file will be created until the end of the simulation. As an example, to store all the conserved
+quantities on a mesh with approximately 300000 triangles on a 2 min interval for 5 hours will result in approximately 350Mb sww file.
+
 \subsection{Boundary Conditions}