Porous Puff (Spatial Analyst)

Summary

Calculates the time-dependent, two-dimensional concentration distribution in mass per volume of a solute introduced instantaneously and at a discrete point into a vertically mixed aquifer.

Learn more about how Porous Puff works

Usage

Syntax

PorousPuff (in_track_file, in_porosity_raster, in_thickness_raster, mass, {dispersion_time}, {longitudinal_dispersivity}, {dispersivity_ratio}, {retardation_factor}, {decay_coefficient})
ParameterExplanationData Type
in_track_file

The input particle track path file.

This is an ASCII text file containing information about the position, the local velocity vector, and the cumulative length and time of travel along the path.

This file is generated using the Particle Track tool.

File
in_porosity_raster

The input raster where each cell value represents the effective formation porosity at that location.

Raster Layer
in_thickness_raster

The input raster where each cell value represents the saturated thickness at that location.

The value for the thickness is interpreted from geological properties of the aquifer.

Raster Layer
mass

A value for the amount of mass released instantaneously at the source point, in units of mass.

Double
dispersion_time
(Optional)

A value representing the time horizon for dispersion of the solute, in units of time.

The time must be less than or equal to the maximum time in the track file. If the requested time exceeds the available time from the track file, the tool is aborted. The default time is the latest time (corresponding to the terminal point) in the track file.

Double
longitudinal_dispersivity
(Optional)

A value representing the dispersivity parallel to the flow direction.

For details on how the default value is determined, and how it relates to the scale of the study, see the How Porous Puff works section in the documentation.

Double
dispersivity_ratio
(Optional)

A value representing the ratio of longitudinal dispersivity over transverse dispersivity.

Transverse dispersivity is perpendicular to the flow direction in the same horizontal plane. The default value is three.

Double
retardation_factor
(Optional)

A dimensionless value representing the retardation of the solute in the aquifer.

Retardation varies between one and infinity, with one corresponding to no retardation. The default value is one.

Double
decay_coefficient
(Optional)

Decay coefficient for solutes undergoing first-order exponential decay (for example, radionuclides) in units of inverse time.

The default is zero, corresponding to no decay.

Double

Return Value

NameExplanationData Type
out_raster

The output raster of the concentration distribution.

Each cell value represents the concentration at that location.

Raster

Code Sample

PorousPuff example 1 (Python window)

This example executes the tool on the required inputs and outputs a raster of the concentration distribution.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outPorousPuff = PorousPuff("trackfile.txt", "gwporo", "gwthick", 50, 10000, "", 3,
                         "", "")
outPorousPuff.save("c:/sapyexamples/output/outporpuff")
PorousPuff example 2 (stand-alone script)

This example executes the tool on the required inputs and outputs a raster of the concentration distribution.

# Name: PorousPuff_Ex_02.py
# Description: Calculates the time-dependent, two-dimensional 
#              concentration distribution in mass per volume of a 
#              solute introduced instantaneously and at a discrete 
#              point into a vertically mixed aquifer.

# Requirements: Spatial Analyst Extension
# Author: ESRI

# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

# Set environment settings
env.workspace = "C:/sapyexamples/data"

# Set local variables
inTrackFile = "trackfile.txt"
inPorosityRaster = "gwporo"
inThicknessRaster = "gwthick"
mass = 50
dispersionTime = 10000
longitudinalDispersivity = ""
dispersivityRatio = 3 
retardationFactor = "" 
decayCoefficient = 0


# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute PorousPuff
outPorousPuff = PorousPuff(inTrackFile, inPorosityRaster, inThicknessRaster, 
                        mass, dispersionTime, longitudinalDispersivity,
                        dispersivityRatio, retardationFactor, 
                        decayCoefficient)

# Save the output 
outPorousPuff.save("c:/sapyexamples/output/outporpuff")

Environments

Related Topics

Licensing Information

ArcView: Requires Spatial Analyst
ArcEditor: Requires Spatial Analyst
ArcInfo: Requires Spatial Analyst

6/29/2011