Local Terrain
Definition
Local terrain refers to the detailed shape of the ground and near-surface features at neighborhood to site scales—slopes, microdepressions, berms, swales, road crowns, and small retaining walls. These subtle features control drainage, walkability, and accessibility much more than coarse regional elevation maps. High-resolution lidar, drone photogrammetry, and careful field surveys capture local terrain, which then feeds hydrologic models, accessibility audits, and urban design. Because small errors can reverse flow paths, quality control and breaklines are vital. Local terrain also interacts with built form to create microclimates: cool pockets in parks, wind tunnels on streets, and shading patterns that affect comfort and energy use.
Application
Engineers design curb ramps and ADA-compliant routes; landscape architects site raingardens and berms for stormwater; cyclists plan low-gradient corridors; emergency managers model neighborhood flood pathways; and utilities map sag points where water or gas may accumulate. Outdoor event planners use local terrain to design flows and stages that remain safe during rain.
FAQ
Why do city drainage maps fail during intense storms?
Because coarse DEMs miss curb heights, driveways, and small barriers. Local terrain models capture these controls and reveal realistic overland flow.
How often should local terrain be updated?
After major construction, resurfacing, or natural events that reshape surfaces. For dynamic sites, annual updates maintain reliability.
Can smartphones collect useful terrain data?
Yes—barometer, GNSS, and LiDAR (on some devices) provide quick checks, but professional surveys are preferred for design-grade accuracy.
What’s a good way to share terrain with non-experts?
Combine shaded relief with simple arrows showing flow direction and hotspots; add short videos from rain events to build intuition.
SUPPORT
© 2025 GISCARTA