ArcMap

Create Contours

Summary

Creates and smooths contours from an input raster.

Usage

  • Set the Map Scale parameter to the scale that your cartographic products will print. The tool uses this parameter to optimize contour display in output products.

  • Specific fields are required for the Out Contour Features parameter value. The Out Contour Features parameter value should be a Defense Mapping data model feature class.

  • The following process generates the contours:

    1. Create contours by executing the Spatial Analyst Contour tool.
    2. Smooth contours by applying a Defense Mapping-specific algorithm.
    3. Calculate contour fields that pertain to Defense Mapping data models.

  • You can use the Maximum vertices per feature parameter to subdivide a feature but only when output features will contain a large number of vertices (multimillions). This parameter produces similar output to that created by the Dice tool. This parameter is intended as a way to subdivide extremely large features that can cause issues, for example, when storing, analyzing, or drawing the features. Choosing a limit is dependent on the available memory on the machine where the tool is being run and the size of the feature (larger features require more memory). Most modern machines running 64-bit software do not typically have issues with individual features containing hundreds of thousands or millions of vertices. If you do encounter issues, setting this parameter to a large value, such as 1 million, may help.

Syntax

arcpy.defense.CreateContours(Input_Raster, Map_Scale, Base_Contour, Contour_Interval, Index_Interval, Include_Zero_Contour, Out_Contour_Features, Contour_Subtype, {Input_Area_of_Interest}, {Raster_Elevation_Units}, {Contour_Elevation_Units}, {Resample_Raster}, {max_vertices_per_feature})
ParameterExplanationData Type
Input_Raster
[Input_Raster,...]

A list of rasters from which contours will be created.

Raster Layer
Map_Scale

Specifies the scale at which the cartographic product will be printed. The tool optimizes cartographic display by setting a minimum feature length based on this scale.

  • 1:5000 —Contour printing will be optimized for scale 1:5,000.
  • 1:7500 —Contour printing will be optimized for scale 1:7,500.
  • 1:10000 —Contour printing will be optimized for scale 1:10,000.
  • 1:12500 —Contour printing will be optimized for scale 1:12,500.
  • 1:25000 —Contour printing will be optimized for scale 1:25,000.
  • 1:50000 —Contour printing will be optimized for scale 1:50,000. This is the default.
  • 1:100000 —Contour printing will be optimized for scale 1:100,000.
  • 1:250000 —Contour printing will be optimized for scale 1:250,000.
  • 1:500000 —Contour printing will be optimized for scale 1:500,000.
  • 1:1000000 —Contour printing will be optimized for scale 1:1,000,000.
String
Base_Contour

The base contour value. Contours are generated above and below this value to cover the entire value range of the input raster. Setting this value to 5 and the contour interval to 10 will produce contour lines at 5, 15, 25, -5, -15, and so on. The default is zero.

Double
Contour_Interval

The interval, or distance, between contour lines. The value can be any positive number.

Double
Index_Interval

The index contour interval.

Double
Include_Zero_Contour

Specifies whether the tool will create a zero contour. A zero contour represents sea level. When generated along a coastline, zero contours can be created inside a water body. Specify INCLUDE_ZERO_CONTOUR if you will generate contours on land areas that are at or below sea level.

  • NO_INCLUDE_ZERO_CONTOUR —A zero contour will not be included. This is the default.
  • INCLUDE_ZERO_CONTOUR —A zero contour will be included.
Boolean
Out_Contour_Features

A feature layer from an existing Defense Mapping feature class. This tool appends contours to this feature class and returns a feature layer.

Feature Layer
Contour_Subtype

A subtype of the Out_Contour_Features parameter value to which contours will be written.

String
Input_Area_of_Interest
(Optional)

An area of interest (AOI) that is contained in a raster and is used to clip the raster before creating contours. A buffer is created before clipping the raster and results in larger output contours that extend beyond the selected AOI.

Feature Layer
Raster_Elevation_Units
[Raster_Elevation_Units,...]
(Optional)

Specifies the measurement units for elevation values in the Input_Raster parameter.

  • Meters —The raster elevation units will be meters.
  • Feet —The raster elevation units will be feet.
String
Contour_Elevation_Units
[Contour_Elevation_Units,...]
(Optional)

Specifies the contour elevation units. The contour elevation units will be created with the same elevation units as raster values unless specified otherwise, such as feet instead of meters.

  • Meters —The contour elevation units will be meters.
  • Feet —The contour elevation units will be feet.
String
Resample_Raster
(Optional)

Specifies whether the Input_Raster parameter value will be resampled before contours are created.

  • NO_RESAMPLE —The Input_Raster parameter value will not be resampled before contours are created.
  • RESAMPLE —The Input_Raster parameter value will be resampled before contours are created. This is the default.
Boolean
max_vertices_per_feature
(Optional)

The vertex limit when subdividing a feature. If no value is specified, the output features will not be split.

Long

Code sample

CreateContours example (Python window)

The following Python window script demonstrates how to use the CreateContours function.

# set gp environment
arcpy.env.workspace="C:/data"

# variables for tool
rasters="elevation.tif"
mapScale="1:12500"
baseContour=0
contourInterval=10

# output feature class must exist
outContours="mgcp.gdb/mgcp/contours"
noIdx="NO_INDEX_CONTOURS"
contourSubtype="FCSubtype"

# execute the tool
arcpy.CreateContours_defense(rasters,mapScale,baseContour,contourInterval,outContours,contourSubtype)

Environments

Licensing information

  • Basic: No
  • Standard: No
  • Advanced: Requires Defense Mapping and Spatial Analyst

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