Working with PRMS parameters

This tutorial shows how to access, edit, remove, and add new PRMS parameters and packages to a GSFLOW model using pyGSFLOW

[1]:

# Package import
import os
import gsflow
import numpy as np

load a demonstration model

[2]:

model_ws = os.path.join("..", "..", "data", "sagehen", "gsflow")

[3]:

control_file = os.path.join(model_ws, "saghen_new_cont.control")
gsf = gsflow.GsflowModel.load_from_file(control_file)

Control file is loaded
Working on loading PRMS model ...
Prms model loading ...
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Reading parameter file : saghen_new_par_0.params
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Warning: ncascade data type will be infered from data supplied
Warning: ncascdgw data type will be infered from data supplied
Warning: ndays data type will be infered from data supplied
Warning: ndepl data type will be infered from data supplied
Warning: ndeplval data type will be infered from data supplied
Warning: nevap data type will be infered from data supplied
Warning: ngw data type will be infered from data supplied
Warning: ngwcell data type will be infered from data supplied
Warning: nhru data type will be infered from data supplied
Warning: nhrucell data type will be infered from data supplied
Warning: nlake data type will be infered from data supplied
Warning: nlake_hrus data type will be infered from data supplied
Warning: nmonths data type will be infered from data supplied
Warning: nobs data type will be infered from data supplied
Warning: nrain data type will be infered from data supplied
Warning: nreach data type will be infered from data supplied
Warning: nsegment data type will be infered from data supplied
Warning: nsnow data type will be infered from data supplied
Warning: nsol data type will be infered from data supplied
Warning: nssr data type will be infered from data supplied
Warning: nsub data type will be infered from data supplied
Warning: ntemp data type will be infered from data supplied
Warning: one data type will be infered from data supplied
------------------------------------
Reading parameter file : saghen_new_par_1.params
------------------------------------
------------------------------------
Reading parameter file : saghen_new_par_2.params
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Reading parameter file : saghen_new_par_3.params
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PRMS model loaded ...
Working on loading MODFLOW files ....
   loading iuzfbnd array...
   loading irunbnd array...
   loading vks array...
   loading eps array...
   loading thts array...
stress period 1:
   loading finf array...
stress period 2:
MODFLOW files are loaded ...

Accessing the PrmsParameters object

The PrmsParameters object allows the user to access data from PRMS parameter files.

[4]:

params = gsf.prms.parameters

Getting a list all of the model parameters

The parameters_list method returns all parameter names in the PrmsParameters object

[5]:

param_names = params.parameters_list

Getting parameter values from the PrmsParameters object

The get_values() method returns a numpy array of parameter values for PRMS parameters

[6]:

ssr2gw = params.get_values("ssr2gw_rate")

Adjusting parameter values

The set_values() method allows the user to adjust a PRMS parameter value

[7]:

ssr2gw = params.get_values("ssr2gw_rate")
ssr2gw *= 0.8
params.set_values("ssr2gw_rate", ssr2gw)

[7]:

array([0., 0., 0., ..., 0., 0., 0.])

Removing a parameter

The remove_record() method allows the user to remove a parameter from the PrmsParameters object.

[8]:

params.remove_record("ssr2gw_rate")

Adding a new parameter

The add_record() method allows the user to add new parameters to the PrmsParameters object

add_record() parameters include

  • name: (str) parameter name

  • values: (np.array, list) numpy array or list of parameter values

  • dimensions: (list) 2 dimensional list that defines 1) the dimension name and 2) the dimension size

  • datatype: (int) PRMS data type

  • filename: (str) Optional parameter that allows the user to set which PRMS parameter file a given parameter is written to. Default is None which writes to the parameter file that contains the PRMS dimensions block.

[9]:

nhru = gsf.mf.nrow * gsf.mf.ncol
ssr2gw = np.random.random(nhru)
params.add_record("ssr2gw_rate",
                  ssr2gw,
                  dimensions=[["nhru", nhru]],
                  datatype=3)