The input parameters to a model run consist of a set of raster files and configuration parameters. The output of the model consists of snapshots of the Digital Elevation Model during its evolution and Hydrodynamic drivers.
The minimum raster input files required are a basement file and one layer of consolidated sediment and one layer of non consolidated sediment. The basement represents a vertical reference used at each raster grid to determine the elevation. The basement represent a non erodible layer (e.g. elevation goes from 0 to >0 but not to negative elevations). The consolidated and non consolidated layers are erodible (e.g. can increase or decrease thickness) and each layer contains a given amount of fine, sand and coarse sediment (represented as mm of sediment). If one type of the layer is non present (e.g. bare shore platform without a beach on top) at the initial time step, the input file still need to be included but with zero thickness everywhere. Building on this simple block structure, a pseudo-topography termed consolidated DEM (cDEM) and a full DEM (fDEM) is obtained by adding the thickness of all layers together. On the cDEM, the elevation at each raster cell is obtained as the cumulative sum of all consolidated blocks (i.e. non-consolidated blocks are not included) and on the fDEM all types of blocks are considered (i.e. equivalent to earth surface elevation). CoastalME is quite flexible regarding the raster input format that can read in. It uses the Geospatial Data Abstraction Library allowing the user to select which type of raster format to be used. The user preferred raster input format is defined, among others, on the configuration parameter file.
The configuration parameters are all stored in ASCII format in MyInputs.dat. To locate this parameter configuration file in your computed you will need to add the path to it on the cme.ini file. Unlike in other LSCB models, such as one-contour models, in CoastalME the user do not define the shoreline location at the initial time step directly but indirectly by defining the layers and the Still Water Level at the beginning of the simulation and CoastalME will then allocate the shoreline accordingly every time step.
The wave direction in the parameter configuration uses the 'true north-based azimuthal system' which is the oceanographic convention in which zero indicates that the waves are propagating towards the north and 90 towards the east. Shoreline orientation is also measured clockwise relative to the azimuth following the convention shown in the figure below, being a shoreline orientation 0 deg when oriented S-N and 90 deg when oriented W-E. By using a local coordinate system at every node along the coast, CoastalME allows the plan-view shoreline to take on arbitrary local orientations, and even fold back upon itself, as complex shapes such as capes and spits form under some wave climates.
The output of the model consists of snapshots of the DEMs (cDEM and fDEM) during its evolution. The model can be configured to write the resulting DEM at any time during the simulation. The output format of DEM files is a user selected format from the GDAL supported raster and vector formats (it can be different as the format used for the initial model input). Other raster output data are: Wave height Active zone location Shore platform erosion potential
Shoreline locations Polygons used to compute alongshore sediment balance Wave directions
Total suspended sediment load