Which data type provides high-resolution elevation, vegetation, and surface roughness data that improve flood, landslide, and structural stability modeling?

• A. Satellite imagery.
• B. Demographic data.
• C. LiDAR data.
• D. Aerial photographs.

Answer: (C)

LiDAR data provide high-resolution elevation, vegetation structure, and surface roughness because they use laser pulses to measure exact distances to surfaces, creating dense 3D point clouds. From these points, you can build precise digital elevation models, capture canopy height and density, and quantify how rough or smooth the ground surface is at fine scales. This level of detail greatly improves flood modeling by revealing accurate terrain slopes, depression storage, stream channels, and surface roughness that controls overland flow and infiltration. In landslide assessments, the ability to map microtopography, scarp features, and subtle slope changes, along with vegetation roots’ influence, leads to better identification of potential failure zones. For structural stability, knowing the near-surface geometry and roughness around buildings enables more accurate load paths and stability analyses. Satellite imagery and aerial photos offer broad coverage but lack the precise elevation and 3D structural information; demographic data isn’t relevant to terrain or hazard modeling.