A Digital Elevation Model (DEM) is a raster-format representation of a continuous surface used to describe Earth’s topography. These models are composed of a series of points, each defined by “X”, “Y”, and “Z” coordinates within a specific spatial reference system.
According to Fallas (2007), a DEM functions as a matrix that stores elevation information for every cell, making it an effective model for representing the Earth’s surface.
Applications of DEMs
The data derived from DEMs is highly valuable and widely applicable across various disciplines. Key fields that benefit from DEMs include hydrology, risk analysis, and urban planning.
In hydrology, DEMs are primarily used to delineate watersheds, determine flow directions, and estimate water accumulation at the cell level. These capabilities are fundamental in modeling water behavior across a landscape.
In risk analysis, DEMs assist in identifying areas that are susceptible to landslides, flooding, or ground instability. Their elevation data supports hazard assessments and informs preventive measures.
Within urban planning, DEMs help evaluate terrain suitability for infrastructure development such as roads, buildings, and public utilities. They are also useful for analyzing the visual impact of proposed projects on the landscape.
Common Outputs Derived from DEMs
Several important spatial products can be generated from DEMs to support analytical tasks. These include:
- Slope maps, which show the steepness of the terrain.
- Contour lines, which illustrate elevation changes.
- Relief and aspect maps, which enhance the understanding of surface orientation and topographic variation.
- Visibility and viewshed maps, commonly used in telecommunications and landscape planning.
- Watershed and basin delineations, essential for hydrologic modeling and water resource management.
These outputs contribute to effective spatial analysis and support informed decision-making across multiple sectors.
Digital Elevation Model (DEM).
