Mapping Table:Mapping Tables
The Mapping Tables consist of an index map name, and a set of IDs, each ID having an associated set of parameter values. GSSHA reads in the integer-based index map, and then builds the floating-point-based map by looking up the ID for each cell and inserting the associated floating-point value from the table. GSSHA expects each ID to have the correct number of values, in the correct order. The number of values and the order of them are given in the following table. The Mapping Table file does not need to contain all of the tables listed in the following table.
| Table Name | # Values | Parameter | Units |
|---|---|---|---|
| ROUGHNESS | 1 | Roughness (n) | none |
| ROUGH_EXP | 1 | Depth varying roughness exponent | none |
| INTERCEPTION | 2 | Storage Capacity (a) | mm |
| Interception coefficient (b) | none | ||
| RETENTION | 1 | Retention depth (dret) | mm |
| GREEN_AMPT_INFILTRATION | 7 | Saturated hydraulic conductivity (Ks) | cm/hr |
| Wetting front suction head (ψƒ) | cm | ||
| Porosity (θs) | m3/m3 | ||
| Pore distribution index (λ) | m3/m3 | ||
| Residual water content (θr) | m3/m3 | ||
| Field Capacity (θfc) | m3/m3 | ||
| Wilting point (θwp) | m3/m3 | ||
| GREEN_AMPT_INITIAL_SOIL_MOISTURE | 1 | Initial soil moisture (θi) | m3/m3 |
| RICHARDS_EQN_INFILTRATION_BROOKS 3 sets of values for each ID |
10 x 3 | Ks | cm/hr |
| θs | m3/m3 | ||
| θr | m3/m3 | ||
| θi | m3/m3 | ||
| θwp | m3/m3 | ||
| θfc | m3/m3 | ||
| Layer thickness (tL) | cm | ||
| λ | none | ||
| Bubbling pressure (ψb) | cm | ||
| Cell size (Δz) | cm | ||
| RICHARDS_EQN_INFILTRATION_HAVERCAMP 3 sets of values for each ID |
12 x 3 | Ks | cm/hr |
| θs | m3/m3 | ||
| θr | m3/m3 | ||
| θi | m3/m3 | ||
| θwp | m3/m3 | ||
| θfc | m3/m3 | ||
| Layer depth | cm | ||
| Havercamp factor α | none | ||
| Havercamp factor Β | none | ||
| Havercamp factor A | none | ||
| Havercamp factor B | none | ||
| Δz | cm | ||
| EVAPOTRANSPIRATION | 5 | Albedo | none |
| Wilting point | (moisture content) | ||
| Vegetation height | m | ||
| Transmission coefficient | none | ||
| Canopy Resistance | s/m | ||
| WELL_TABLE | 2 | IsDynamic | 0 or 1 |
| pumping rate (if static) or time series index (if dynamic) | cms | ||
| OVERLAND_BOUNDARY | 2 | Boundary Type 0 - Regular Cell 1 - Constant Slope 2 - Constant Specified Head 3 - Time Variable Specified Head 4 - Specified hydrograph (cfs) 5 - Specified hydrograph (cms) |
Type 0 - 0.0 Type 1 - slope Type 2 - head (m) Type 3, 4, or 5 - time series index |
| Parameter depends on the type specified by the first parameter | See below | ||
| TIME_SERIES_INDEX | 1 | "Time Series Name" | none |
| GROUNDWATER | 2 | Hydraulic Conductivity | cm/hour |
| Porosity | m3/m3 | ||
| GROUNDWATER_BOUNDARY | 1 | Boundary Value | none |
| AREA_REDUCTION | 1 | Impervious area fraction | [0.0 - 1.0] |
| WETLAND_PROPERTIES | 7 | Initial water depth | cm |
| Retention depth (Darcy flow depth) | cm | ||
| Retention hydraulic conductivity | m/day | ||
| Vegetation height | cm | ||
| Vegetation hydraulic conductivity | m/day | ||
| Vegetation Manning's N | none | ||
| Burn-in depth | cm | ||
| OVR_FLOW_BLOCK | 5 | Area reduction | Fraction (0-1) |
| Upper (North) face blockage | Fraction (0-1) | ||
| Right (East) face blockage | Fraction (0-1) | ||
| Down (South) face blockage | Fraction (0-1) | ||
| Left (West) face blockage | Fraction (0-1) | ||
| BMPS | 10+ | BMP Type | <number> |
| Inflow Type | Fraction (0-1) | ||
| Outflow Type | Fraction (0-1) | ||
| Area | m2 | ||
| Retention depth | mm | ||
| Soil Saturated Hydraulic Conductivity | cm/hr | ||
| Inflow variable (based on BMP type) | <number> | ||
| Outflow variable (based on BMP type) | <number> | ||
| Soil Depth | meters | ||
| TSS Treatment Efficiency | Fraction (0-1) | ||
| Contaminant Treatment Efficiency (repeat for each contaminant | Fraction (0-1) |
The following sections outline the table names, number of parameters, order and type of the parameters, and the table format. Also included is an example table. In the example tables the descriptions have been shortened for display purposes. In all fields of the table, except the ID and descriptions fields, the amount of spacing between the identifiers does not matter. The format of the ID lines is given after the Soil Erosion Factors table is described.
Contents
- 1 12.3.1 Roughness
- 2 12.3.2 Roughness Exponent
- 3 12.3.3 Interception
- 4 12.3.4 Retention
- 5 12.3.5 Green & Ampt Infiltration
- 6 12.3.6 Initial Soil Moisture
- 7 12.3.7 Richards’ Equation, Brooks Option
- 8 12.3.8 Richards’ Equation, Havercamp Option
- 9 12.3.9 Evapo-transpiration
- 10 12.3.10 Wells
- 11 12.3.11 Overland Boundaries
- 12 12.3.12 Time Series Index
- 13 12.3.13 Groundwater
- 14 12.3.14 Groundwater Boundary
- 15 12.3.15 Area Reduction Factor
- 16 12.3.16 Wetlands
- 17 12.3.17 Flow Blockage
- 18 12.3.18 Parameter Line Format
- 19 GSSHA User's Manual
12.3.1 Roughness
The roughness table specifies Manning/Strickler n values for the overland flow domain. This table is always present since overland flow is always running. Roughness values are usually based on land use values.
See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| ROUGHNESS | 1 | Surface Roughness (n) | none | 0.02 – 0.5 |
| ROUGHNESS | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | |||
| ID #2 | Description 1 | Description 2 | ###.### | |||
| etc. | ||||||
| ID #N | Description 1 | Description 2 | ###.### | |||
Example Table
ROUGHNESS "roughness map" NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 SURF_ROUGH 1 cornfield Soil type independent 0.24000 2 urban area Soil type independent 0.19000 3 Forest Soil type independant 0.27000
12.3.2 Roughness Exponent
The roughness exponent table specifies exponent values for depth-varying Manning/Strickler n values for the overland flow domain. This table is for the "b" values in the equation n=n0^(-bh). Values vary from 0.0 (non-depth-varying) to 1.0.
See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| ROUGH_EXP | 1 | Surface Roughness Exponent (b) | none | 0.00 – 1.0 |
| ROUGH_EXP | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | |||
| ID #2 | Description 1 | Description 2 | ###.### | |||
| etc. | ||||||
| ID #N | Description 1 | Description 2 | ###.### | |||
Example Table
ROUGH_EXP "roughness map" NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 ROUGH_EXP 1 cornfield Soil type independent 0.5000 2 urban area Soil type independent 0.43000 3 Forest Soil type independant 0.62000
12.3.3 Interception
The interception table specifies parameters for water being abstracted from the rainfall by the vegetation. This table is usually based on a vegetation or land cover map.
See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
| INTERCEPTION | 2 | Storage capacity | mm | 0.0 - ? |
| Interception Coefficient | none | 0.0 – 1.0 |
| INTERCEPTION | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | ###.### | ||
| ID #2 | Description 1 | Description 2 | ###.### | ###.### | ||
| … | ||||||
| ID #N | Description 1 | Description 2 | ###.### | ###.### | ||
Example Table
INTERCEPTION "interception map" NUM_IDS 3 ID DESCRIPTION1 DESCRIPTION2 STOR_CAPY INTER_COEF 1 Deciduous Trees Independent of soils 1.143 0.245000 2 Coniferous Trees Independent of soils 0.984 0.102000 3 Corn Independent of soils 1.052 0.045000
12.3.4 Retention
This table describes the retention depth used in the overland flow model. It is usually based on land use.
See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
| RETENTION | 1 | Retention depth (dret) | mm | 1.0 – 5.0 |
| RETENTION | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | |||
| ID #2 | Description 1 | Description 2 | ###.### | |||
| … | ||||||
| ID #N | Description 1 | Description 2 | ###.### | |||
Example Table
RETENTION "retention map" NUM_IDS 3 ID DESCRIPTION1 DESCRIPTION2 RETENTION_DEPTH 1 Forest Soil type independent 1.800000 2 Residential Soil type independent 0.800000 3 Corn Soil type independent 2.300000
12.3.5 Green & Ampt Infiltration
This table is used to describe the soil properties for use with the Green and Ampt or Green and Ampt with Redistribution infiltration methods. Both of those methods also require that the GREEN_AMPT_INITIAL_SOIL_MOISTURE table also be defined. This table is usually defined from a combination of soil type and land use maps.
See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| GREEN_AMPT_INFILTRATION | 7 | Ks (Saturated Hydraulic Conductivity) | cm/hr | 0.01 – 2.0 |
| ψf (Capillary Suction Head) ) | cm | 10.0 – 100.0 | ||
| θs (Porosity) | m3/m3 | 0.25 – 0.60 | ||
| λ (Pore Index Value) | none | 1.0 – 4.0 | ||
| θr (Residual Saturation) | m3/m3 | 0.01 – 0.1 | ||
| θf (Field Capacity) | m3/m3 | 0.01 – 0.3 | ||
| θwp (Wilting Point) | none | 0.03 – 0.25 |
| GREEN_AMPT_INFILTRATION | "Index Map Name" | ||||||||
| NUM_IDS | #### | ||||||||
| Text Line | |||||||||
| ID #1 | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### |
| ID #2 | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### |
| … | |||||||||
| ID #N | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### |
Example Table
GREEN_AMPT_INFILTRATION “green and ampt infil map” NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 HYDR_COND CAPIL_HEAD POROSITY PORE_INDEX RESID_SAT FIELD_CAPACITY 1 Row Crop SL 0.048342 8.34 0.501000 0.234000 0.015000 0.3300 2 Row Crop CL 0.026000 12.4 0.485000 0.257000 0.012000 0.2700
12.3.6 Initial Soil Moisture
The initial soil moisture table is required for either of the Green and Ampt infiltration methods. This table is usually based on a combination of soil type and vegetation or land cover types.
See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Range |
|---|---|---|---|---|
| GREEN_AMPT_INITIAL_SOIL_MOISTURE | θi | 1 | m3/m3 | θr-θs |
| GREEN_AMPT_INITIAL_SOIL_MOISTURE | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | |||
| ID #2 | Description 1 | Description 2 | ###.### | |||
| … | ||||||
| ID #N | Description 1 | Description 2 | ###.### | |||
Example Table
GREEN_AMPT_INITIAL_SOIL_MOISTURE "green and ampt moisture map" NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 SOIL_MOISTURE 1 Row Crops SL 0.250000 2 Row Crops CL 0.200000
12.3.7 Richards’ Equation, Brooks Option
The Richards' Equation infiltration methods are the most rigorous that GSSHA has to offer. These methods have three defined layers and thus have three lines of parameters for each index value; the top layer is the first line, the bottom layer is the third line. The parameter sets all begin at character #87 on the line (see also Parameter Line Format) but for the 2nd and 3rd lines the ID and description spaces are blank (GSSHA ignores whatever is there.) The maximum number of cells parameter should be bigger than the sum of the depth of each layer divided by the delta Z of that layer.
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| RICHARDS_EQN_INFILTRATION_BROOKS 3 sets of values for each ID, one set of values per line for each soil layer |
10 x 3 | Ks | cm/hr | 0.05 – 23.5 |
| θs (Saturated hydraulic conductivity) | m3/m3 | 0.4 – 0.55 | ||
| θr (Residual saturation) | m3/m3 | 0.01 – 0.1 | ||
| θi (Initial soil moisture) | m3/m3 | θr-θs | ||
| θwp (Wilting point) | m3/m3 | 0.03 – 0.25 | ||
| θfc (Field capacity) | m3/m3 | 0.25 - 0.35 | ||
| d (total layer depth) | cm | NA | ||
| λ | none | 1.0 – 4.0 | ||
| ψb (Bubbling pressure) | cm | 5.0 – 100.0 | ||
| Δz (Numerical solver layer depth) | cm | 0.1 – 10.0 |
| RICHARDS_EQN_INFILTRATION_BROOKS | "Index Map Name" | ||||||||||
| NUM_IDS | #### | ||||||||||
| MAX_NUMBER_CELLS | #### | ||||||||||
| Text Line | |||||||||||
| ID #1 | Description 1 | Description 2 | ### | ### | ### | ### | ### | ### | ### | ### | ### |
| ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ID #2 | Description 1 | Description 2 | ### | ### | ### | ### | ### | ### | ### | ### | ### |
| ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| … | |||||||||||
| ID #N | Description 1 | Description 2 | ### | ### | ### | ### | ### | ### | ### | ### | ### |
| ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
Example Table
RICHARDS_EQN_INFILTRATION_BROOKS "map name"
NUM_IDS 2
MAX_NUMBER_CELLS 165
ID DESCRIPTION1 DESCRIPTION2 HYD_COND POROSITY RESID_SAT SOIL_MOIST WILTING_PT FIELD_CAP DEPTH LAMBDA BUB_PRESS DELTA_Z
1 Clay 0.1 0.5 0.1 0.25 0.15 0.35 10.0 3.0 -50.0 1.0
0.1 0.5 0.1 0.25 0.15 0.35 20.0 3.0 -50.0 2.0
0.1 0.5 0.1 0.25 0.15 0.35 50.0 3.0 -50.0 5.0
2 Silty Clay 0.2 0.48 0.09 0.25 0.15 0.35 10.0 2.7 -35.0 1.0
0.2 0.48 0.09 0.25 0.15 0.35 20.0 2.7 -35.0 2.0
0.2 0.48 0.09 0.25 0.15 0.35 50.0 2.7 -35.0 5.0
12.3.8 Richards’ Equation, Havercamp Option
Like the Brooks option the Havercamp option has three soil layers. The first line of each parameter set is for the top layer and the third line the bottom layer. The maximum number of cells parameter should be bigger than the sum of the depth of each layer divided by the delta Z of that layer. See also Parameter Line Format and the Brooks Option.
| Table Name | # Values | Parameter | Units | Range |
|---|---|---|---|---|
| RICHARDS_EQN_INFILTRATION_HAVERCAMP 3 sets of values for each ID One set of values per line for each soil layer |
12 x 3 | Ks | cm/hr | 0.05 – 23.5 |
| θs | m3/m3 | 0.4 – 0.55 | ||
| θr | m3/m3 | 0.01 – 0.1 | ||
| θi | m3/m3 | θr-θs | ||
| θwp | m3/m3 | 0.03 – 0.25 | ||
| θfc | m3/m3 | 0.25 – 0.35 | ||
| dL | cm | NA | ||
| α | none | fit to curve | ||
| β | none | fit to curve | ||
| A | none | fit to curve | ||
| B | none | fit to curve | ||
| Δz | cm | 0.1 – 10.0 |
| RICHARDS_EQN_INFILTRATION_HAVERCAMP | "Index Map Name" | ||||||||||||
| NUM_IDS | #### | ||||||||||||
| MAX_NUMBER_CELLS | #### | ||||||||||||
| Text Line | |||||||||||||
| ID #1 | Description 1 | Description 2 | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### |
| ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ID #2 | Description 1 | Description 2 | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### |
| ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| … | |||||||||||||
| ID #N | Description 1 | Description 2 | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### |
| ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
| ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | ### | |||
Example Table
RICHARDS_EQN_INFILTRATION_HAVERCAMP "map name"
NUM_IDS 2
MAX_NUMBER_CELLS 165
ID DESCRIPTION1 DESCRIPTION2 HYD_COND POROSITY RESID_SAT SOIL_MOIST WILTING_PT FIELD_CAP DEPTH Alpha Beta A B DELTA_Z
1 Clay 0.1 0.5 0.09 0.25 0.25 0.35 20 80 1.3 125 1.8 1.0
0.1 0.5 0.09 0.35 0.25 0.25 30 80 1.3 125 1.8 2.0
0.1 0.5 0.09 0.45 0.25 0.35 50 80 1.3 125 1.8 5.0
2 Sand 1.0 0.4 0.01 0.25 0.03 0.25 10 35 4.0 1175 4.7 1.0
1.0 0.4 0.01 0.35 0.03 0.25 40 35 4.0 1175 4.7 2.0
1.0 0.4 0.01 0.35 0.03 0.25 50 35 4.0 1175 4.7 5.0
12.3.9 Evapo-transpiration
This table holds the parameters for the evapo-transpiration routine. See also Parameter Line Format and the Computation of evaporation and evapo-transpiration
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| EVAPO-TRANSPIRATION | 4 | Albedo | none | 0.0 – 1.0 |
| Vegetation Height | m | 0.1 – 10.0 | ||
| Vertical Radiation Coefficient | none | 0.0 – 1.0 | ||
| Canopy Resistance | s/m | 0.0 – 500.0 |
| EVAPOTRANSPIRATION | "Index Map Name" | ||||||
| NUM_IDS | #### | ||||||
| Text Line | |||||||
| ID #1 | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### |
| ID #2 | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### |
| … | |||||||
| ID #N | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### |
Example table
EVAPOTRANSPIRATION "et map" NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 ALBEDO WILTING_PT VEG_HIEGHT V_RAD_COEF CANOPY_RESIST 1 Row Crops 0.100000 0.120000 0.500000 0.100000 45.000000 2 Forest 0.200000 0.080000 7.500000 0.200000 200.00000
12.3.10 Wells
The well table uses the standard line format (see Parameter Line Format) but also uses the time series index table.
The Is Dynamic? parameter is a flag to indicate if the flow rate is static (0) or dynamic (1). If the flow rate is static then the value is the pumping/injection rate. If it is dynamic then the value should be the ID of a time series as specified in the time series index table. The well IDs are used in the map, just like other tables, but map IDs of 0 are ignored.
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| WELL_TABLE | 2 | Is Dynamic? | none | 1=yes, 0=no |
| Value | cms or none | -10000..10000 or Time Series ID |
| WELL_TABLE | "Index Map Name" | |||
| NUM_IDS | #### | |||
| Text Line | ||||
| ID #1 | Description 1 | Description 2 | # | ###.### |
| ID #2 | Description 1 | Description 2 | # | ###.### |
| … | ||||
| ID #N | Description 1 | Description 2 | # | ###.### |
Example table
TIME_SERIES_INDEX "" NUM_IDS 1 1 "Municipal well #4" WELL_TABLE "well map" NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 Is_Dynamic? Value 1 Static well 0 2.53 2 Dynamic well 1 1
In the example above, since well #1 is static, the value is the pumping rate. Since well #2 is dynamic, the value (1) refers to the ID in the time series index (1="Municipal well #4").
12.3.11 Overland Boundaries
The overland boundaries table works in conjunction with the time series index table. See also Parameter Line Format and Overland Boundaries.
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| OVERLAND_BOUNDARY | 2 | Boundary Type | none | 0=none 1=Specified slope 2=Constant specified head 3=Time variable specified head 4=Hydrograph source (cfs) 5=Hydrgraph source (cms) |
| Boundary Value | none for type 0, 1, and 3 m above sea level for type 2 cfs for type 3 cms for type 4 |
Type 0: 0.00 Type 1: 0.0000001 - 0.01 Type 2: 0.0 .. 5.0 above cell elevations Type 3: IDs in time series index, heads between -1.0..20.0 above cell elevation. Type 4: IDs in the time series index, input flow rates in cubic feet per second (cfs) Type 5: IDs in the time series index, input flow rates in cubic meters per second (cms) |
| OVERLAND_BOUNDARY | "Index Map Name" | |||
| NUM_IDS | #### | |||
| Text Line | ||||
| ID #1 | Description 1 | Description 2 | # | ###.### |
| ID #2 | Description 1 | Description 2 | # | ###.### |
| … | ||||
| ID #N | Description 1 | Description 2 | # | ###.### |
Example table
TIME_SERIES_INDEX "" NUM_IDS 2 1 "Municipal well #4" 2 "Storm surge" OVERLAND_BOUNDARY "bdy" NUM_IDS 3 ID DESCRIPTION1 DESCRIPTION2 BDY_TYPE BDY_VAL 1 specified slope 1 0.001000 2 specified head 3 2 3 none 0 0.0
In the example above, ID 1 is a constant specified slope (for allowing the water to drain off the grid in a location other than the outlet cell), ID 2 is a time-variable specified head and the boundary value of 2 is the ID in the time series index (2="Storm surge"). ID 3 is used in the grid where non-boundary-condition cells are located.
12.3.12 Time Series Index
The time series index table is a special table in that it is used by other tables as a means of associating an ID with a time series name, rather than specifying parameters for a process. This table does not refer to an index map, nor does it have description fields as the other tables do.
Example Table
TIME_SERIES_INDEX "" NUM_IDS 2 ID Time series name... 1 "Municipal well #4" 2 "Storm surge"
12.3.13 Groundwater
The groundwater table is used to specify spatially variable values of hydraulic conductivity and porosity without creating a continuous map.
See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
| GROUNDWATER | 2 | Hydraulic Conductivity | cm/hr | <math>10^{-9}</math> .. <math>10^4</math> |
| Porosity | none | 0.001 – 0.5 |
| GROUNDWATER | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | ###.### | ||
| ID #2 | Description 1 | Description 2 | ###.### | ###.### | ||
| … | ||||||
| ID #N | Description 1 | Description 2 | ###.### | ###.### | ||
Example Table
GROUNDWATER "gw properties map" NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 HYD_COND POROSITY 1 Karst region 120.0 0.10000 2 Glacial till 0.0036 0.20000
12.3.14 Groundwater Boundary
The groundwater boundary table maps ID values to groundwater boundary codes. See also Parameter Line Format and groundwater boundary conditions.
| Table Name | # Values | Parameter | Units | Typical Range |
| GROUNDWATER_BOUNDARY | 1 | Boundary value | none | 0-7 |
| GROUNDWATER_BOUNDARY | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | |||
| ID #2 | Description 1 | Description 2 | ###.### | |||
| … | ||||||
| ID #N | Description 1 | Description 2 | ###.### | |||
Example Table
GROUNDWATER_BOUNDARY "gw boundary map" NUM_IDS 3 ID DESCRIPTION1 DESCRIPTION2 BOUNDARY_VALUE 1 regular cell 1 2 static head 2 3 dynamic well 3 4 flux river 4 5 head river 5 6 static well 6 7 lake 7
Of course, the index map in this example is simple enough to also be the boundary map as well. Wells are better set up using the well table rather than here.
12.3.15 Area Reduction Factor
The area reduction factor reduces the potential infiltration by the specified fraction. See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
| AREA_REDUCTION | 1 | Impervious area fraction | none | 0.0 – 1.0 |
| AREA_REDUCTION | "Index Map Name" | |||||
| NUM_IDS | #### | |||||
| Text Line | ||||||
| ID #1 | Description 1 | Description 2 | ###.### | |||
| ID #2 | Description 1 | Description 2 | ###.### | |||
| … | ||||||
| ID #N | Description 1 | Description 2 | ###.### | |||
Example Table
AREA_REDUCTION "impervious area map" NUM_IDS 3 ID DESCRIPTION1 DESCRIPTION2 IMPERVIOUS_AREA 1 High-density urban 0.800000 2 low-density urban 0.300000 3 natural area 0.000000
12.3.16 Wetlands
The wetlands table has the parameters for the overland flow wetland process. Currently limited to <300 unique wetlands. The wetland map is similar in nature to the well map; the areas that don't have wetlands should be marked as having ID 0. See also Parameter Line Format
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| WETLAND_PROPERTIES | 7 | Initial Depth | cm | 0.1 - 600.0 |
| Retention Depth | cm | 1.0 - 500.0 | ||
| Retention Hydraulic Conductivity | m/day | 0.1 - 1000.0 | ||
| Vegetation Height | cm | 5.0 - 200.0 | ||
| Vegetation Hydraulic Conductivity | m/day | 0.1 - 1000.0 | ||
| Vegetation Manning N | none | 0.02 – 0.5 | ||
| Burn In Depth | cm | 0.0 – 500.0 |
| WETLAND_PROPERTIES | "Index Map Name" | ||||||||
| NUM_IDS | #### | ||||||||
| Text Line | |||||||||
| ID #1 | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### |
| ID #2 | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### |
| … | |||||||||
| ID #N | Description 1 | Description 2 | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### | ###.### |
Example table
WETLAND_PROPERTIES "wetland map" NUM_IDS 2 ID DESCRIPTION1 DESCRIPTION2 INIT_DEPTH RET_DEPTH RET_HYD_COND VEG_HEIGHT VEG_HYD_COND VEG_N BURN_IN_DEPTH 1 Lower Wetland 65.0 50.0 20.0 1.0 120.0 0.35 50.0 2 Upper Wetland 75.0 100.0 110.0 1.5 200.0 0.35 75.0
12.3.17 Flow Blockage
The overland flow blockage table specifies how much of each cell face does not communicate with the neighboring cell.
| Table Name | # Values | Parameter | Units | Typical Range |
|---|---|---|---|---|
| OVR_FLOW_BLOCK | 5 | Area Reduction | none (fraction of area) | 0.0 - 1.0 |
| Upper (north) face flow blockage | none (fraction of cell edge length) | 0.0 - 1.0 | ||
| Right (east) face flow blockage | none (fraction of cell edge length) | 0.0 - 1.0 | ||
| Lower (south) face flow blockage | none (fraction of cell edge length) | 0.0 - 1.0 | ||
| Left (west) face flow blockage | none (fraction of cell edge length) | 0.0 - 1.0 |
12.3.18 Parameter Line Format
For each of the mapping tables, except for the time series index table and the sediment properties table, the parameter lines follow a mixed fixed/free format. The ID number portion of the line must be 6 characters, and each of the two descriptions must be 40 characters. After this (starting at character 87) the parameter values can be spaced as desired. The description fields are generally used to describe the land use and soil type that each of the IDs refers to so that the file is human-readable. These fields can contain any desired information, however, as GSSHA simply ignores them. The same applies for the text line above the parameter lines; this is for your use to help in identifying what goes where or whatever else you want to write there.
[ID ][Description 1 ][Description 2 ]Parameter values...
GSSHA User's Manual
- 12 Mapping Table
- 12.1 File Description
- 12.2 Index Maps
- 12.3 Grid-based Mapping Tables
- 12.4 ID Line Format
- 12.5 Example Mapping Table File
- 12.6 Stream Mapping Tables
- 12.7 Sediment Erosion Mapping Tables
- 12.7 Constituent Mapping Tables
