1. Automating parflow preprocessing steps for DEMs
John A Koudelka

2. Topics
Background
Methods
Results
Conclusions
Photo: John A Koudelka

3. Background
ParFlow Is an integrated watershed model that simulates surface and subsurface flow.
Data Processing
Soil Moisture – Little Washita Watershed.

4. Methods Manual Processing Steps Automation Python (Windows)
1. Raster to ASCII
2. ASCII – No Header
3. Dataset Metrics (cell size, # rows, # columns, No Data value, x and y origin)
4. ParFlow Fortran files
- Remove Pits
- Create Slope Files
- Generate Solid File
Automation
Remove pits
Create Slope Files
Generate Solid File
Python (Windows)
Python (OS X)

5. Methods Manual ASCII No Header ASCII No Pits ARC/INFO GRID ASCII
Datasets
ASCII No Header
ASCII No Pits
ARC/INFO GRID
ASCII
Cell Size
# Rows
# Cols
X origin
Y origin
ND Value
Variables
Raster To ASCII
Remove Pits
Create Slopes
CreateSolid File
Functions
Remove Header
X Slopes
Y Slopes
Solid File
ParFlow Input

6. Methods Automated Raster To ASCII ASCII ARC/INFO GRID 1. X Slopes
Y Slopes
Solid File
ParFlow Input
Remove Pits
Create Slopes
CreateSolid File
Cell Size
# Rows
# Cols
X origin
Y origin
ND Value
Remove Header
ASCII No Pits
ASCII No Header
ASCII 2.

7. Methods Challenges GDAL User Distribution Logos From:
Python –
GADL -
NumPy -

8. Results Processing Steps: Python Script 1 Python Script 2
import os
#import numpy
import subprocess
## ****** GRAB DEM PARAMS ***** ##
#export raster to ascii
path="/Users/johnkoudelka/ParF/Data/LittleBear/preprocess"
os.chdir(path)
fileName='dem.txt'
outFileName='pf_dem.txt'
asciiFile=open("dem.txt")
rLine=asciiFile.readline().strip().split(" ")
ncols=rLine[9]
nrows=rLine[9]
xllcorner=rLine[5]
yllcorner=rLine[5]
cellSize=rLine[6]
NDval=rLine[2]
#create the modified ascii DEM
pf_ascii=open(outFileName,'w')
i=0
#write it
while (i<int(nrows)):
rLine=asciiFile.readline()
pf_ascii.write(rLine +'\n’)
i=i+1
Processing Steps:
Python Script 1
Raster to ASCII conversion
Python Script 2
Set header information to variables
Write DEM without header information
Execute modified Fortran codes
Script 2 – Code Snieppet

9. Conclusions Automation Future work Fortran & Python Computing Platform
GDAL
Photo: John A Koudelka

10. The End
Questions?