Version 2.0 of MESH_parameters_hydrology.ini introduces several enhancements and improvements over older formats of the file. The file allows comments, adds names to identify parameters, and extends the channel routing parameter section. The file is labelled with the '2.0:' version number.
Overview
MESH_parameters_hydrology.ini contains four sections: option flags, channel routing parameters, hydrologic parameters that are not tied to any one GRU, and hydrologic parameters that are tied to specific GRUs.
Consult the Parameters Selection page for more information about specific parameters and recommended parameter values.
Page contents:
Sample File
2.0: MESH Hydrology parameters input file (Version 2.0)##### Option Flags #####----# 0 # Number of option flags##### Channel routing parameters #####-------# 1 # Number of channel routing parametersWF_R2 0.842##### GRU independent hydrologic parameters #####-------# 0 # Number of GRU independent hydrologic parameters##### GRU dependent hydrologic parameters #####-------# 3 #Number of GRU dependent hydrologic parametersZSNL 0.1 0.1 0.1ZPLS 0.1 0.1 0.1ZPLG 0.1 0.1 0.1
File Structure
Comments
Lines that begin with '!' are prescribed comment lines, which are skipped when reading the file. These lines are not included when numbering the lines in the following sections.
!> Everything following the colon in the version string is ignored.
Field structure
Nearly all fields in the file use the same free format, whitespace delimited structure.
FIELD_NAME Value1 Value2 ... ValueN
Notes:
FIELD_NAMEis not case-sensitive;FIELD_NAME,field_name, andFiEld_NaMeare equivalentFIELD_NAMEmay be tied to a specific control flag, land surface scheme, or routing routine (see the tables in each section below)
There are constraints on the allowed total line length, field length, and number of fields. Exceeding these constraint can cause an instability when reading from the file.
| Maximum line length | 500 characters |
| Maximum field length | 20 characters |
Total number of delimited fields (including FIELD_NAME) | 50 |
Sections
Header information
The first line in the file must begin with "2.0:" followed by whitespace. Any comment before this line is ignored.
!> Lines that begin with '!' are skipped as comments.!> The version string of the new format file is required: '2.0:'. The colon is required.!> Everything following the colon in the version string is ignored.2.0: MESH Hydrology parameters input file (Version 2.0)
Option flags
The first two lines are skipped, and then the number of option flags to read from the file is read. The text after this number is ignored.
##### Option Flags #####----# 0 # Number of option flags!> There are no option flags recognized or active at present.
Each option flag is read as one additional line. No option flags/additional lines are read if this number is zero.
Channel routing parameters
This section includes the river roughness coefficients (WF_R2) included in previous versions of the file, but also other parameters to parameterize channel sinuosity and capacity, and new parameters for RTE.
The first two lines are skipped, and then the number of parameters to read from the file is read. The text after this number is ignored.
##### Channel routing parameters #####-------# 1 # Number of channel routing parameters!> The number of [Value] should match the number of river classes from the drainage database.!> NRVR ----- 1WF_R2 0.842
Each parameter is read as one additional line. No parameters/additional lines are read if this number is zero.
The line must begin with a field name from the tables below. Values are listed after the field name. For all channel routing parameters, the number of values expected is the number of river classes (NRVR) defined by IAK in MESH_drainage_database.r2c.
If all the grids in a domain have IAK=2, two values for these parameters are expected. However, because no grid has IAK=1, only the second value is used.
!> NRVR ----- 1 ----- 2WF_R2 0.0 0.842
Channel routing parameters (WF_ROUTE)
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| WF_R2 | 1->NRVR | Real | River channel roughness factor for channel routing, which incorporates a channel shape and width to depth ratio as well as Manning's n; typical values range from 0.3 to 1.0; a higher number corresponds to an increased river roughness; typically calibrated | -- | s m-1/3 |
| WF_R1 | 1->NRVR | Real | Overbank factor, applied to WF_R2 to determine the overbank roughness factor; WF_R1 in fact equals WF_R2*WF_R1 | 2.0 | -- |
| WF_A1 | 1->NRVR | Real | Meander factor, applied to the channel length | 1.0 | -- |
| WF_A2 | 1->NRVR | Real | Bankfull/drainage area relationship intercept (i.e., min. cross-sectional area) | 11.0 | -- |
| WF_A3 | 1->NRVR | Real | Bankfull/drainage area relationship coefficient | 0.43 | -- |
| WF_A4 | 1->NRVR | Real | Bankfull/drainage area relationship exponent | 1.0 | -- |
Channel routing parameters (RTE)
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| R2N | 1->NRVR | Real | Channel Manning's n; typically calibrated | -- | |
| R1N | 1->NRVR | Real | Overbank Manning's n; typically calibrated | -- | |
| MNDR | 1->NRVR | Real | Meander factor, applied to the channel length | 1.0 | -- |
| WIDEP | 1->NRVR | Real | Channel width to depth ratio | 10.0 | -- |
| AA2 | 1->NRVR | Real | Bankfull/drainage area relationship intercept (i.e., min. cross-sectional area) | 1.1 | -- |
| AA3 | 1->NRVR | Real | Bankfull/drainage area relationship coefficient | 0.043 | -- |
| AA4 | 1->NRVR | Real | Bankfull/drainage area relationship exponent | 1.0 | -- |
BASEFLOWFLAG wf_lzs
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| pwr | 1->NRVR | Real | Exponent on the lower zone storage in the lower zone function; values may range from 2.0 to 3.0 when using an hourly time-step; typically calibrated | -- | -- |
| flz | 1->NRVR | Real | Lower zone function; values may range from 1.0e-06 to 1.0e-04; typically calibrated | -- | -- |
GRU-Independent hydrologic parameters
GRU-independent parameters are those that are not tied to any one GRU. A single value applies to the parameter across the entire domain.
The first two lines are skipped, and then the number of parameters to read from the file is read. The text after this number is ignored.
##### GRU independent hydrologic parameters #####-------# 5 # Number of GRU independent hydrologic parametersSOIL_POR_MAX 0.8SOIL_DEPTH 3.393S0 0.962T_ICE_LENS -10.0!> YEAR ----- 1 ----- 2 ----- 3 ----- 4 ----- 5t0_ACC 250.58 250.58 311.11 390.98 257.47
Each parameter is read as one additional line. No parameters/additional lines are read if this number is zero.
The line must begin with a field name from the tables below. Values are listed after the field name. The number of values expected is parameter-specific.
FROZENSOILINFILFLAG (only CLASS 3.6)
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| SOIL_POR_MAX | 1 | Real | Maximum porosity of the soil | -- | -- |
| SOIL_DEPTH | 1 | Real | Maximum permeable depth of the soil (of the rooting zone) | -- | m |
| S0 | 1 | Real | Maximum saturation of the soil during melt; from 0.75-1.0 | -- | mm3 mm-3 |
| T_ICE_LENS | 1 | Real | Minimum temperature to allow formation of an ice sheet at the surface of the soil; from -50.0-0.0 | -- | deg C |
| t0_ACC | 1->n_years | Real | Opportunity time of infiltration into the frozen or freezing soil; set to 0.0 to allow the model to calculate this; a value is required for as many years as are simulated | -- | hr |
BASEFLOWFLAG luo_2012
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| WrchrgIni | 1 | Real | Initial constant recharge for cold start | -- | mm hr-1 |
| QbIni | 1 | Real | Initial constant baseflow for cold start | -- | mm hr-1 |
BASEFLOWFLAG wf_lzs
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| WrchrgIni | 1 | Real | Initial depth of storage in the lower zone | 0.0 | kg m-2 s-1 |
GRU-Dependent hydrologic parameters
GRU-independent parameters are those that are parameterized by GRU.
The first two lines are skipped, and then the number of parameters to read from the file is read. The text after this number is ignored.
##### GRU dependent hydrologic parameters #####-------# 3 #Number of GRU dependent hydrologic parameters!> The number of [Value] should match the number of GRUs from CLASS.ini.!> GRU ------- 1 ------- 2 ------- 3ZSNL 0.58 0.58 0.58ZPLS 0.48 0.48 0.48ZPLG 0.46 0.46 0.46
Each parameter is read as one additional line. No parameters/additional lines are read if this number is zero.
The line must begin with a field name from the tables below. Values are listed after the field name. For all GRU-dependent parameters, the number of values expected is the number of GRUs (NM/NTYPE) defined in MESH_drainage_database.r2c (':ClassCount' - 1) and MESH_parameters_CLASS.ini.
CLASS 3.6
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| ZSNL | 1->NTYPE | Real | Minimum depth to consider 100% cover of snow on the ground surface | -- | m |
| ZPLS | 1->NTYPE | Real | Maximum depth of liquid water allowed to be stored on the ground surface for snow-covered areas | -- | m |
| ZPLG | 1->NTYPE | Real | Maximum depth of liquid water allowed to be stored on the ground surface for snow-free areas | -- | m |
IWF 2 and 3 – PDMROF/LATFLOW (only CLASS 3.6)
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| CMAX | 1->NTYPE | Real | Maximum depth of storage (liquid water) | -- | m |
| CMIN | 1->NTYPE | Real | Minimum depth of storage (liquid water) | -- | m |
| B | 1->NTYPE | Real | Shape factor | -- | -- |
| K1 | 1->NTYPE | Real | Time constant for the first linear reservoir | -- | hr |
| K2 | 1->NTYPE | Real | Time constant for the second linear reservoir | -- | hr |
FROZENSOILINFILFLAG (only CLASS 3.6)
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| FRZC | 1->NTYPE | Real | Coefficient of the equation for the infiltration of meltwater into frozen or freezing soils; from 1-3 | -- | -- |
PBSMFLAG (only CLASS 3.6)
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| fetch | 1->NTYPE | Real | Distance of unobstructed wind flow; minimum 300.0 | -- | m |
| Ht | 1->NTYPE | Real | Vegetation height; a smaller values allows more erosion | -- | m |
| N_S | 1->NTYPE | Real | Vegetation number density; typically 1.0-500.0; recommended 300.0 for crops and grass, 1.0 for forests and shrubs | -- | count m-2 |
| A_S | 1->NTYPE | Real | Vegetation diameter; typically 0.0-2.0; recommended 0.003 for crops and grass, 0.5-1.0 for forests and shrubs | -- | m2 |
| Distrib | 1->NTYPE | Real | Snow distribution factor, controlling drift; set 0.0-1.0 for first GRU and >= 1.0 for the rest; recommended is to set GRU1=0.0 and all others =1.0, so that the remainder of the GRUs receive equal drift | -- | -- |
BASEFLOWFLAG luo_2012
| Field Name | No. of Values | Type | Description | Default Value | Units |
|---|---|---|---|---|---|
| dgwsh | 1->NTYPE | Real | Delay time of the overlying soil layers in the aquifer | -- | hr |
| agwsh | 1->NTYPE | Real | Recession constant of the aquifer | -- | -- |