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Digital elevation models

Find out how Nearmap can help with digital elevation models (DEMs), power mapping, surveying, and GIS insights. Learn its uses, types, and benefits.
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Using a digital elevation model is the backbone of landscape intelligence. It fuels DEM imagery, enables precise DEM mapping, and powers every 3D elevation model decision from flood planning to urban design.

What is the digital elevation model?

A digital elevation model (DEM) is a high-resolution, computer-generated grid that represents the Earth’s bare surface with elevation values at every cell. Imagine a topographic map stripped of vegetation and built structure. What remains is your DEM model. It’s a virtual terrain you can analyze, slice, overlay, and derive insights from in GIS software or interactive landscape models.

What is the purpose of the digital elevation model?

DEM is not just data — it’s insight. It’s the foundation for:
  • Watershed planning
  • Terrain analysis
  • Construction layout
  • Infrastructure design
  • Flood and risk modeling
In short, every decision that depends on accurate ground elevation—whether to place a transmission line, model stormwater flooding or design a bike trail—starts with DEM.

What does a digital elevation model look like?

Telltale signs of a DEM include:
  • Raster grid of elevation values
  • Color heatmaps (blues at low, reds at high)
  • Contour overlays — lines connecting equal elevation
  • Interactive 3D visuals — valleys, ridges, plateaus emerging in high definition
In GIS apps, the DEM becomes an analytical canvas. Turn contours on or off, generate hillshade for visual depth, apply slope analysis for roadway planning, or run watershed delineation for environmental assessment.

Importance of a digital elevation model

DEM delivers reliable terrain intelligence quickly and accurately. If you miss grade the slope on a highway ramp, you risk safety. Ignore elevation data under a new subdivision, and you risk drainage failure. Every sector, from forestry to energy, relies on DEM because it helps anticipate issues before they show up as costly mistakes.

Who uses the digital elevation model?

Organizations across sectors use DEMs as foundational terrain data. Here are key professionals and industries that rely on digital elevation models:
  • Civil engineers use digital elevation models (DEMs) and GIS for grading and drainage plans
  • Surveyors convert raw field data into finished DEM maps
  • Water resource managers model runoff and flood flows
  • Telecom planners analyze line-of-sight via DEM imagery
  • Urban designers build city plans with interactive 3D terrain
  • Agriculture specialists optimize terraces and erosion control

Difference between digital elevation model and digital surface model

DEM models show bare Earth — no trees, buildings, or vehicles. DSM, or digital surface model, includes everything visible. DEM is essential for accurate grading and drainage. DSM performs canopy studies, building height, and urban analysis. Mistaking one for the other can lead to errors in design, permitting, and modeling.

Advantages of a digital elevation model

Digital elevation models offer a range of advantages that make them essential tools across industries. Here are some of the top benefits of using DEMs:
  • High precision and reliable analytics
  • Compatible with GIS, CAD, and 3D software
  • Supports automated slope, aspect, and watershed extraction
  • Versatile: usable from local parcel to continental scale

Limitations of the digital elevation model

While digital elevation models are powerful tools, they come with a few limitations that users should keep in mind when relying on them for critical decisions. Some of the key challenges include:
  • Less effective in dense forest or steep slopes (data voids)
  • Quality depends on source: LiDAR vs photogrammetry vs satellite
  • Without regular updates, DEM becomes outdated — terrain changes, construction shifts, and erosion happen

Types of digital elevation models

Digital elevation models come in several forms, each tailored to specific applications, accuracy levels, and data sources. Here are the most common types of digital elevation models:
  • Raster DEMs: uniform grid
  • TIN DEMs: Triangulated Irregular Network — geometry-based
  • Contour-derived DEMs: from topographic lines
  • LiDAR DEM: high-grade laser mapping
  • Photogrammetric DEM: aerial imagery
  • Satellite DEM: global coverage (e.g., SRTM, ASTER)

Technology behind the digital elevation model

Every accurate digital elevation model relies on a combination of powerful technologies and data sources. From airborne lasers to radar satellites, here’s how the model captures and processes data:
  • LiDAR: laser pulses from aircraft generate 10–30 cm-grade DEMs
  • Photogrammetry: uses overlapping aerial photos
  • InSAR/SAR: radar from satellites (Sentinel, TerraSAR-X)
  • RTK and drones: compact, cost-effective surveys
These datasets are processed with software: point classification, ground filtering, gridding, and surface modeling.

How is the digital elevation model created?

Creating a digital elevation model is a multi-step process that transforms raw spatial data into a usable elevation surface. Here’s how that workflow typically unfolds:
  • Data capture (LiDAR, drone, imagery, satellite)
  • Filtering classify ground, separate canopy/structures
  • Interpolation create a grid via TIN or IDW
  • Validation compared against control points
  • Export files like GeoTIFF, ASCII, or proprietary formats

Uses for a digital elevation model

Digital elevation models are essential tools across industries, enabling more accurate spatial planning and terrain-based decision-making. Here are some of the most common and impactful uses for DEMs:
  • Floodplain delineation
  • Road/highway corridor design
  • Utility and line-of-sight modeling
  • Site planning, excavation, and earthwork volume
  • Forest canopy and timber volume analysis
  • Solar farm layout, land use planning

Types of terrain analysis from DEM

Digital Elevation Models (DEMs) are powerful tools for analyzing terrain features and understanding landscape characteristics. DEM data can yield the following key types of terrain analysis:
  • Slope: gradient of the terrain
  • Aspect: direction a slope faces
  • Hillshade: simulated shadows for visualization
  • Watershed delineation: drainage boundaries
  • Visibility and viewshed: coverage analysis

Differences between DEM, DSM, DTM, and MNT

Understanding the differences between elevation data types is crucial for selecting the right product for your project. Here’s a quick breakdown of DEM, DSM, DTM, and MNT — each serving a distinct purpose in terrain and surface modeling:
  • DEM: bare Earth
  • DSM: earth + objects
  • DTM: DEM + terrain breaklines
  • MNT: French equivalent of DEM

Future trends in digital elevation models

Digital Elevation Models (DEMs) are rapidly evolving with advances in technology, enabling more precise, dynamic, and integrated terrain data. Emerging trends are reshaping how DEMs are generated, updated, and used across industries:
  • AI / Machine learning for automated noise filtering, classification
  • Real-time DEM updates from frequent drone flyovers
  • 3D elevation model streaming in cloud GIS
  • Crowdsourced terrain models
  • Integration into BIM, XR, and digital twins
  • Hyper-resolution global DEMs (10 cm scale soon)

How a digital elevation model supports modern analysis

Modern GIS platforms (Nearmap, ArcGIS, Trimble, QGIS, Global Mapper) include built-in DEM tools for slope, volume, solar radiation, and more. Combined with high-resolution aerial or drone data, DEM enables scalable terrain simulation, regression analysis, and smart asset management.

Case Studies

Flood mapping with DEM

A coastal city faced repeated floods. Using LiDAR-derived DEM at 20 cm resolution, they modeled storm surges across terrain, defined flood zones, and adjusted city planning. The results are infrastructure built in safer zones, improved emergency routing, and fewer flood losses.

Telecom line-of-sight

A telecom provider used high-resolution DEM mapping to simulate tower-to-tower signal paths. DEM modeling enabled precise antenna placement, reducing trial-based installs and cutting costs by 25%.

Digital elevation models GIS — why it matters

In GIS environments, DEM lays the foundation. It’s used as a base layer for map visuals, 3D interactivity, spatial analysis, and terrain simulation. Analysts can extract ridgelines, catchments, and volumetrics with a few clicks.

DEM software and tools

To manage, analyze, and visualize DEM data, professionals typically use specialized software. Top platforms include: Popular DEM-capable software includes:
  • ArcGIS Pro, Spatial Analyst
  • QGIS, SAGA GIS
  • Global Mapper, AutoCAD Civil 3D
  • Cloud platforms like Nearmap, Cesium, Google Earth Engine
  • Specialized tools: WhiteBox GAT, GRASS GIS

DEM surveying: best practices

When creating and validating high-quality DEM data, adhere to these field-tested guidelines:
  • Ground control points for precision
  • LiDAR calibration with GNSS RTK
  • Multiple flight lines overlap on UAVs
  • Vegetation and architecture filtering during classification
  • Accuracy checks via RMS error

Choosing the right DEM for your project

Terrain data comes in different resolutions and formats depending on the use case. Here’s how to match the DEM type to your needs:
  • Survey-grade (10–30 cm): engineering sites, infrastructure
  • Mid-resolution (1–2 m): city planning, forestry
  • Coarse (10 m+): regional, global studies
The match needs resolution and update frequency.

Integrating DEM into project workflows

Use DEM as a dynamic part of your planning and design processes. Here’s a typical integration flow:
  • Import the surface into CAD for grading
  • Combine with utility maps for cut/fill
  • Generate reports: volume, slope, aspect
  • Export visual 3D views for presentations
  • Deploy terrain data to mobile apps

Sustainability and environmental benefits

High-quality DEM enables better environmental stewardship: erosion control, flood risk reduction, vegetation management, and precision agriculture.

Frequently asked questions

Fast answers about 3D mapping

People use DEM for flood risk mapping, road design, drainage, visibility study, solar feasibility, and more.

DEM processes ground data into elevation cells. GIS tools derive slope, volume, watershed, and visuals.

Air-map platforms like Nearmap, ArcGIS Pro, QGIS, and Global Mapper show DEMs.

DEM is bare Earth. DSM includes trees, buildings, and surface features.

Accuracy depends on the source—LiDAR DEM is highly precise (20 cm), and satellite DEM is coarser (10 m).

Increasingly, yes, thanks to drone fleets and cloud processing pipelines.

Yes, training ensures accurate workflow: setup, processing, and validation.

Want high-resolution, current Digital Elevation Model data for your projects? Get in touch with Nearmap. We deliver accurate DEM imagery, robust DEM mapping tools, and cloud-based DEM software—so your terrain intelligence stays one step ahead.
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