GENERATE_WATER_RISE

Calculates the water rise from a given area or from a specific elevation.

  • FILENAME- filename of the terrain layer(s) to process. If an empty value is passed in, all loaded terrain data will be used. This parameter can be listed more than once to specify multiple input files, like FILENAME="FILENAME_1" FILENAME="FILENAME_2".
  • ELEVATION_TO_RISE_FROM -Specify an elevation that the water rise will calculated from.
  • WATER_RISE_POLY_FILE - Specify the file name for area feature(s) that water rise should be calculated from. Typically this would be a lake or pond.
  • MAX_DEPTH- specify the height of the water rise and the depression fill depth. This can be height above a specific elevation using ELEVATION_TO_RISE_FROM or height above an area.
  • ELEV_UNITS- specify the units for elevation values in the command

Shared Parameters

  • SPATIAL_RES - specifies spacing of grid points used to calculate the watershed. A smaller grid spacing results in higher fidelity, but the calculation process will take longer. Typically you'll want to use the default value which is the minimum spatial resolution of all loaded data. Should be formatted as x_resolution,y_resolution. The units are the units of the current global projection. For example, if UTM was the current global projection and you wanted to use a grid with a 30 meter spacing, the parameter/value pair would look like SPATIAL_RES=30.0,30.0.
  • SPATIAL_RES_METERS - specifies spatial resolution to use in meters. The value in meters will automatically be converted to the current view/export projection units. For example, to do an export at 2.0 meter spacing (or as close as you can get to that in the current units), use SPATIAL_RES_METERS=2.0, or to do an export at 1.0 meters in X by 1.5 meters in Y, use SPATIAL_RES_METERS="1.0,1.5".
  • SAMPLING_METHOD - specifies the sampling method to use when sampling the terrain layers involved in the watershed calculation. The following values are supported:
    • DEFAULT - Use either automatic resampling based on export or layer resampling, depending on setting of global flag about whether to resample on export
    • AUTO - Automatically select a resampling method based on how the export resolution and bounds compare to the original layout for a layer. For example if you export to a lower resolution a box averager of appropriate size may be used automatically
    • LAYER - Use the sampling method set for each layer
    • The list of SAMPLING_METHOD values for the IMPORT command can also be specified to use a particular sampling method for all layers being exported/
  • FILL_GAPS - specifies that small gaps in between and within the data sets being used to generate the watershed will be filled in by interpolating the surrounding data to come up with an elevation for the point in question. This option is on by default, specify FILL_GAPS=NO to turn off.
  • LAYER_DESC - specifies the name to assign to this layer. If no layer description is provided, the default name of "Watershed" will be used.
  • KEEP_ZERO_AT_ZERO - specifies whether or not to modify 0 (typically ocean) values to allow flow to continue across expanses of 0 elevation. The default is to enable this so 0 values don't change. If you want to model flow across 0 surfaces, add KEEP_ZERO_AT_ZERO=NO.

SAMPLES

Calculate the water rise from the area defined by "riverarea.shp" if the water was to increase 20 ft.

GLOBAL_MAPPER_SCRIPT VERSION="1.00" ENABLE_PROGRESS=NO
IMPORT FILENAME="CROPPED_DEM.dem" LAYER_DESC="SOURCE_LAYERS"
IMPORT FILENAME="riverarea.shp" LAYER_DESC="POLYFILE"
GENERATE_WATER_RISE MAX_DEPTH=20 WATER_RISE_POLY_FILE="POLYFILE" ELEV_UNITS=FEET
EXPORT_VECTOR GEN_PRJ_FILE=YES FILENAME="outwaterrise_elev860.shp" \
	TYPE=SHAPEFILE SHAPE_TYPE=AREAS
UNLOAD_ALL

Calculate a 2 ft water rise from the given elevation of 860 ft.

GLOBAL_MAPPER_SCRIPT VERSION="1.00" ENABLE_PROGRESS=NO
IMPORT FILENAME="CROPPED_DEM.dem" LAYER_DESC="SOURCE_LAYERS"
GENERATE_WATER_RISE MAX_DEPTH=2 ELEVATION_TO_RISE_FROM=860 ELEV_UNITS=FEET
EXPORT_VECTOR GEN_PRJ_FILE=YES FILENAME="outwaterrise_elev860.shp" \
TYPE=SHAPEFILE SHAPE_TYPE=AREAS
UNLOAD_ALL