Difference between revisions of "Mapping Table:Mapping Tables"

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| Left (West) face blockage || Fraction (0-1)
 
| Left (West) face blockage || Fraction (0-1)
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| RowSpan=11 | [[Mapping_Table:Mapping_Tables#12.3.18_BMPS|BMPS]]
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| BMP Type || <number>
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| Inflow Type || Fraction (0-1)
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| Outflow Type || Fraction (0-1)
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| Area || m2
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| Retention depth || mm
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| Soil Saturated Hydraulic Conductivity || cm/hr
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| Inflow variable (based on BMP type) || <number>
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| Outflow variable (based on BMP type) || <number>
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| Soil Depth || meters
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| TSS Treatment Efficiency || Fraction (0-1)
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| Contaminant Treatment Efficiency (repeat for each contaminant || Fraction (0-1)
 
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Latest revision as of 23:22, 27 September 2023

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
1 set per line

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
1 set per line

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.

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


Table Format
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


Table Format
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


Table Format
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


Table Format
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



Table Format
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 θrs


Table Format
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 θrs
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


Table Format
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 θrs
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


Table Format
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


Table Format
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


Table Format
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)


Table Format
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


Table Format
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


Table Format
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


Table Format
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


Table Format
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