Creating Project Files:Continuous Simulation Project File

The following example project file will instruct GSSHA to perform a continuous simulation with the Penman-Monteith evapo-transpiration scheme, Green & Ampt infiltration with redistribution (Ogden & Saghafian, 1997), surface retention storage, spatially distributed surface roughness, and rainfall interception. Furthermore, ASCII GRASS maps of spatially distributed depth on the watershed will be written every 30 minutes. WMS is used to develop the inputs, including the MAPPING_TABLE file and index maps of spatially varied watershed properties, such as land use, soil-texture, and combination land-use/soil-texture maps. In this case the project file would look like.

 
GSSHAPROJECT
WATERSHED_MASK		simple.msk
WMS                     8.1
ELEVATION		simple.ele

FLINE                   simple.map
QUIET
GRIDSIZE            	50.0
ROWS                	10
COLS                	10
TIME STEP           	20.0
PRECIP_FILE		simple.gag
RAIN_INV_DISTANCE
LONG_TERM
LATITUDE            	37.15
LONGITUDE		99.34
GMT			-7
ET_CALC_PENMAN
SOIL_MOIST_DEPTH	0.50
TOP_LAYER_DEPTH         0.20
EVENT_MIN_Q		0.01
HMET_WES		simple.hmt
INF_REDIST
MAPPING_TABLE       	simple.cmt
DIFFUSIVE_WAVE
CHANNEL_INPUT	  	simple.cip
STREAM_CELL             simple.gst
SUMMARY             	simple.sum
HYD_FREQ            	30
OUTLET_HYDRO        	simple.hyd
MAP_FREQ		30
MAP_TYPE		0
DEPTH			simple.dep

The Mapping Table file simple.cmt would supply all the needed parameters for overland flow, ET, infiltration, and soil moisture accounting. The mapping table with only the required inputs is shown below. To increase the ability to view the MAPPING_TABLE in the Wiki, the actual table format has been modified. For the correct format please see Section 12.

GSSHA_INDEX_MAP_TABLES
INDEX_MAP                "landuse.idx" "landuse"
INDEX_MAP                "soiltype.idx" "soiltype"
INDEX_MAP                "STLU.idx"     "stlu"
ROUGHNESS "landuse"
NUM_IDS 2
ID    DESCRIPTION1        DESCRIPTION2         SURF_ROUGH
1     developed                                0.05
2     forest                                   0.15
INTERCEPTION "landuse"
NUM_IDS 2
ID    DESCRIPTION1        DESCRIPTION2         STOR_CAPY  INTER_COEF
1     developed                                0.01       0.01
2     forest                                   1.00       0.2
RETENTION "2"
NUM_IDS 2
ID    DESCRIPTION1        DESCRIPTION2         RETENTION_DEPTH
1     developed                                0.1
2     forest                                   2.0
GREEN_AMPT_INFILTRATION "soiltype"
NUM_IDS 2
ID    DESCRIPTION1    HYDR_COND CAPIL_HEAD POROSITY PORE_INDEX RESID_SAT FIELD_CAPACITY
1     clay            0.010000    4.950000    0.437000    0.694000    0.020000    0.30
2     silt            0.300000    2.000000    0.450000    0.400000    0.010000    0.35
GREEN_AMPT_INITIAL_SOIL_MOISTURE "soiltype"
NUM_IDS 2
ID    DESCRIPTION1       DESCRIPTION2         SOIL_MOISTURE
1     clay                                    0.30000
2     silt                                    0.25000                                   
EVAPOTRANSPIRATION "stlu"
NUM_IDS 3
ID    DESCRIPTION1 DESCRIPTION2 ALBEDO  WILTING_PT  VEG_HEIGHT  V_RAD_COEF CANOPY_RESIST
1     silt         forest       0.2     0.2         10.0        0.5       150.0
2     silt         developed    0.4     0.2          0.1        0.1       300.0 
3     clay         forest       0.2     0.1         10.0        0.5       150.0

As these examples indicate, the complexity of GSSHA simulations is determined by the contents of the project file (and the availability of data, of course). Project files can be built which incorporate every non-exclusive option of GSSHA to perform continuous simulations with complete spatial variability in rainfall, interception, retention storage, evapo-transpiration, overland flow, channel flow, unsaturated zone calculation for infiltration and soil moisture accounting, and lateral saturated groundwater flow with feedback to the unsaturated zone, stream network, and overland flowplane. In the construction of project files, the user must provide all required data for a given option, and avoid specifying mutually exclusive options.