Slope (3D Analyst)

Summary

Identifies the slope (gradient, or rate of maximum change in z-value) from each cell of a raster surface.

Learn more about how Slope works

Illustration

Slope illustration
Slope_3d (InRas1, OutRas)

Usage

Syntax

Slope_3d (in_raster, out_raster, {output_measurement}, {z_factor})
ParameterExplanationData Type
in_raster

The input surface raster.

Raster Layer
out_raster

The output slope raster.

Raster Dataset
output_measurement
(Optional)

Determines the measurement units (degrees or percentages) of the output slope data.

  • DEGREE The inclination of slope will be calculated in degrees.
  • PERCENT_RISE Keyword to output the percent rise, also referred to as the percent slope.
String
z_factor
(Optional)

Number of ground x,y units in one surface z unit.

The z-factor adjusts the units of measure for the z units when they are different from the x,y units of the input surface. The z-values of the input surface are multiplied by the z-factor when calculating the final output surface.

If the x,y units and z units are in the same units of measure, the z-factor is 1. This is the default.

If the x,y units and z units are in different units of measure, the z-factor must be set to the appropriate factor, or the results will be incorrect. For example, if your z units are feet and your x,y units are meters, you would use a z-factor of 0.3048 to convert your z units from feet to meters (1 foot = 0.3048 meter).

Double

Code Sample

Slope example 1 (Python window)

This example determines the slope values of the input surface raster.

import arcpy
from arcpy import env
env.workspace = "C:/data"
arcpy.Slope_3d("elevation", "C:/output/outslope01", "DEGREE", 0.3043)
Slope example 2 (stand-alone script)

This example determines the slope values of the input surface raster.

# Name: Slope_3d_Ex_02.py
# Description: Identifies the rate of maximum change 
#              in z-value from each cell.
# Requirements: 3D Analyst Extension

# Import system modules
import arcpy
from arcpy import env

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

# Set local variables
inRaster = "elevation"
outRaster = "C:/output/outslope02"
outMeasurement = "DEGREE"
zFactor = 0.3043

# Check out the ArcGIS 3D Analyst extension license
arcpy.CheckOutExtension("3D")

# Execute Slope
arcpy.Slope_3d(inRaster, outRaster, outMeasurement, zFactor)

Environments

Related Topics

Licensing Information

ArcView: Requires 3D Analyst or Spatial Analyst
ArcEditor: Requires 3D Analyst or Spatial Analyst
ArcInfo: Requires 3D Analyst or Spatial Analyst

6/10/2013