Creating Project Files:Involved Project File

Infiltration can be included in the simulations using one of the optional methods. For the sake of this example, Green & Ampt infiltration will be simulated, which requires additional inputs of porosity, saturated hydraulic conductivity, capillary head parameter, and initial water content as maps or as Mapping Table inputs related to index maps. We will assume that these data are saved in maps named “simple.por”, “simple.sat”, “simple.cap”, and “simple.moi”, respectively. Spatially distributed rainfall will also be input, with two rain gages using inverse distance squared interpolation. The rainfall data are stored in a file called “simple.gag”. A single channel, which consists of two links, will also be simulated. The channel input data file will be called “simple.cip”, with a the channel/grid connectivity file "simple.gst". The format of the channel input files is described in Chapter 5.

The resulting project file for this simulation appears as:

GSSHAPROJECT
WATERSHED_MASK          simple.msk
ELEVATION               simple.ele
QUIET
GRIDSIZE                50.0
ROWS                    10
COLS                    10
TOT_TIME                2000
TIME STEP               20.0
MANNING_N               0.036
PRECIP_FILE		simple.gag
RAIN_INV_DISTANCE
GREEN_AMPT
POROSITY		simple.por
CONDUCTIVITY		simple.sat
CAPILLARY		simple.cap
MOISTURE		simple.moi
CHAN_EXPLIC
CHANNEL_INPUT           simple.cip
STREAM_CELL             simple.gst
SUMMARY                 simple.sum
HYD_FREQ                30
OUTLET_HYDRO            simple.hyd

Notice that the START_DATE and START_TIME project file cards have been removed. These two cards are required only for spatially- and temporally-uniform precipitation, because this information is contained in the precipitation input data file. Also note that the OUTCOL, OUTROW, and OUTSLOPE project file cards have been removed, because they are not required when channel routing is enabled. The outlet of the catchment is determined from the overland flow/channel flow connectivity information provided by the link and node maps.

The four maps simple.por, simple.sat, simple.cap, and simple.moi can also be replaced with tabled values related to an index map, such as a soil texture map. This is the standard way processes are assigned parameter values in WMS 6.1 and higher. In this case the project file would look like.

GSSHAPROJECT
WMS 8.1
WATERSHED_MASK          simple.msk

FLINE                   simple.map
ELEVATION               simple.ele
UNITS                   0
QUIET
GRIDSIZE                50.0
ROWS                    10
COLS                    10
TOT_TIME                2000
TIME STEP               20.0
MANNING_N               0.036
PRECIP_FILE		simple.gag
RAIN_INV_DISTANCE
GREEN_AMPT
MAPPING_TABLE           simple.cmt
DIFFUSIVE_WAVE
CHANNEL_INPUT           simple.cip
STREAM_CELL	        simple.gst
SUMMARY                 simple.sum
HYD_FREQ                30
OUTLET_HYDRO            simple.hyd

And the Mapping Table file named simple.cmt would contain the values of hydraulic conductivity, porosity, suction head, and initial moisture, which would be indexed to integer based index maps, such as a soil-texture map, as described in Section 12. Notice that WMS adds informtion it needs to the project file, including the WMS release verion, and the GIS like map information in the FLINE card. GSSHA ignores these and any other unrecognized project cards, and provides a warning to the screen during execution. Notice that WMS substitues DIFFUSIVE_WAVE for CHAN_EXPLIC, either is acceptable.