Topo to Raster by File (Spatial Analyst)

License Level:BasicStandardAdvanced

Summary

Interpolates a hydrologically correct raster surface from point, line, and polygon data using parameters specified in a file.

Learn more about how Topo to Raster works

Usage

Syntax

TopoToRasterByFile (in_parameter_file, {out_stream_features}, {out_sink_features}, {out_residual_feature}, {out_stream_cliff_error_feature}, {out_contour_error_feature})
ParameterExplanationData Type
in_parameter_file

The input ASCII text file containing the inputs and parameters to use for the interpolation.

The file is typically created from a previous run of Topo to Raster with the optional output parameter file specified.

In order to test the outcome of changing the parameters, it is easier to make edits to this file and rerun the interpolation than to correctly issue the Topo to Raster tool each time.

File
out_stream_features
(Optional)

Output feature class of stream polyline features.

The polyline features are coded as follows:

  1. Input stream line not over cliff.
  2. Input stream line over cliff (waterfall).
  3. Drainage enforcement clearing a spurious sink.
  4. Stream line determined from contour corner.
  5. Ridge line determined from contour corner.
  6. Code not used.
  7. Data stream line side conditions.
  8. Code not used.
  9. Line indicating large elevation data clearance.
Feature Class
out_sink_features
(Optional)

Output feature class of remaining sink point features.

Feature Class
out_residual_feature
(Optional)

The output point feature class of all the large elevation residuals as scaled by the local discretisation error.

All the scaled residuals larger than 10 should be inspected for possible errors in input elevation and stream data. Large-scaled residuals indicate conflicts between input elevation data and streamline data. These may also be associated with poor automatic drainage enforcements. These conflicts can be remedied by providing additional streamline and/or point elevation data after first checking and correcting errors in existing input data. Large unscaled residuals usually indicate input elevation errors.

Feature Class
out_stream_cliff_error_feature
(Optional)

The output point feature class of locations where possible stream and cliff errors occur.

The locations where the streams have closed loops, distributaries and streams over cliffs can be identified from the point feature class. Cliffs with neighboring cells that are inconsistent with the high and low sides of the cliff are also indicated. This can be a good indicator of cliffs with incorrect direction.

Points are coded as follows:

  1. True circuit in data streamline network.
  2. Circuit in stream network as encoded on the out raster.
  3. Circuit in stream network via connecting lakes.
  4. Distributaries point.
  5. Stream over a cliff (waterfall).
  6. Points indicating multiple stream outflows from lakes.
  7. Code not used.
  8. Points beside cliffs with heights inconsistent with cliff direction.
  9. Code not used.
  10. Circular distributary removed.
  11. Distributary with no inflowing stream.
  12. Rasterized distributary in output cell different to where the data stream line distributary occurs.
  13. Error processing side conditions—an indicator of very complex streamline data.
Feature Class
out_contour_error_feature
(Optional)

The output point feature class of possible errors pertaining to the input contour data.

Contours with bias in height exceeding five times the standard deviation of the contour values as represented on the output raster are reported to this feature class. Contours that join other contours with a different elevation are flagged in this feature class by the code 1; this is a sure sign of a contour label error.

Feature Class

Return Value

NameExplanationData Type
out_surface_raster

The output interpolated surface raster.

Raster

Code Sample

TopoToRasterByFile example 1 (Python window)

This example creates a hydrologically correct TIFF surface raster from a parameter file defining the input point, line, and polygon data.

import arcpy
from arcpy import env  
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outTTRByFile = TopoToRasterByFile("topotorasterbyfile.txt", 
                   "C:/sapyexamples/output/out_streams.shp", "#",
                   "C:/sapyexamples/output/out_resids.shp")
outTTRByFile.save("C:/sapyexamples/output/ttrbyfout.tif")
TopoToRasterByFile example 2 (stand-alone script)

This example creates a hydrologically correct Grid surface raster from a parameter file defining the input point, line, and polygon data.

# Name: TopoToRasterByFile_Ex_02.py
# Description: Interpolates a hydrologically correct 
#    surface from point, line, and polygon data using
#    parameters specified in a file.
# Requirements: Spatial Analyst Extension

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

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

# Set local variables
inParameterFile = "topotorasterbyfile.txt"

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

# Execute TopoToRasterByFile
outTTRByFile = TopoToRasterByFile(inParameterFile, "#", "C:/sapyexamples/output/out_resids2.shp")

# Save the output 
outTTRByFile.save("C:/sapyexamples/output/ttrbyfout02")

Environments

Related Topics

Licensing Information

ArcGIS for Desktop Basic: Requires Spatial Analyst or 3D Analyst
ArcGIS for Desktop Standard: Requires Spatial Analyst or 3D Analyst
ArcGIS for Desktop Advanced: Requires Spatial Analyst or 3D Analyst
11/8/2012