ArcGIS Pro Tutorial: Extracting Elevation Values from DEM with ArcGIS Pro

ArcGIS Pro Tutorial: Extracting Elevation Values from DEM

Digital Elevation Models (DEMs) are essential datasets in GIS that represent the Earth’s surface topography. This comprehensive tutorial will guide you through extracting elevation values from DEM data using ArcGIS Pro, one of the most powerful GIS desktop applications available.

Prerequisites

• ArcGIS Pro installed and licensed
• Digital Elevation Model (DEM) dataset
• Point, line, or polygon features for elevation extraction
• Basic understanding of GIS concepts

Method 1: Extract Values to Points

Step 1: Prepare Your Data

Start by opening ArcGIS Pro and creating a new project. Add your DEM raster dataset and point feature class to the map. Ensure both datasets are in the same coordinate system to avoid projection errors.

Step 2: Access the Extraction Tool

Navigate to the Analysis tab and open the Geoprocessing pane. Search for “Extract Values to Points” in the tool search box. This tool will extract elevation values from your DEM at each point location.

Step 3: Configure Tool Parameters

In the Extract Values to Points tool dialog:

• Set Input Point Features to your point layer
• Set Input Raster to your DEM dataset
• Choose an output feature class location and name
• Leave the “Interpolate values” option checked for smoother results

Step 4: Execute and Review Results

Click Run to execute the tool. Once complete, open the attribute table of the output point feature class. You’ll find a new field (typically named “RASTERVALU” or similar) containing the extracted elevation values at each point location.

Method 2: Extract Values Along Lines or Polygons

Using Zonal Statistics for Polygons

For polygon features, use the Zonal Statistics as Table tool to extract elevation statistics:

• Open the Zonal Statistics as Table tool
• Set the polygon layer as the input zone data
• Set the DEM as the input value raster
• Choose statistics to calculate (mean, minimum, maximum, etc.)
• Run the tool to generate a statistics table

Extracting Along Line Features

For line features, first convert lines to points at regular intervals:

• Use the “Generate Points Along Lines” tool
• Specify point placement interval (e.g., every 10 meters)
• Use the resulting points with Extract Values to Points tool

Advanced Techniques

Extracting Multiple Elevation Attributes

When working with large datasets, you can extract additional terrain attributes simultaneously:

• Slope values
• Aspect data
• Hillshade information
• Curvature measurements

Batch Processing Multiple Features

For processing multiple feature classes:

• Use the Batch option in geoprocessing tools
• Create model builder workflows for repetitive tasks
• Utilize Python scripting for complex extraction operations

Quality Control and Validation

Always validate your extracted elevation values:

• Check for null or invalid values in the output
• Compare results with known elevation benchmarks
• Verify coordinate system consistency
• Review data resolution and accuracy expectations

Troubleshooting Common Issues

Null Values in Output

If you encounter null values, check:

• Coordinate system compatibility
• Feature locations within DEM extent
• Data resolution mismatch
• NoData areas in the source DEM

Performance Optimization

For large datasets, consider:

• Clipping DEM to feature extent
• Building pyramids and statistics
• Using appropriate data resolution
• Processing in tiled sections

Practical Applications

Elevation extraction has numerous real-world applications:

• Environmental impact assessments
• Infrastructure planning and development
• Flood risk analysis
• Wildlife habitat modeling
• Archaeological site analysis
• Telecommunications tower placement

Best Practices

• Always backup original data before processing
• Document coordinate systems and datum information
• Use appropriate DEM resolution for your analysis scale
• Validate results with ground truth data when possible
• Consider terrain complexity in your analysis limitations