Which term describes the mapping of landforms and surface features used in site selection for bridge projects?

• A. Hydrotechnical surveys
• B. Topographic surveys
• C. Seismic surveys
• D. Geotechnical surveys

Answer: (B)

Mapping landforms and surface features used in choosing where to place a bridge is described by topographic surveys. This type of survey captures elevations, contours, landforms, drainage patterns, vegetation, and other surface characteristics to create an accurate picture of the ground surface. That surface picture is essential for deciding a feasible alignment, estimating required earthwork, and understanding accessibility, drainage, and potential constructability constraints. By knowing how the terrain rises and falls, engineers can select routes and approaches that minimize excavation, avoid flood-prone areas, and meet clearance and grade requirements. The other survey types focus on different aspects: hydrotechnical surveys address water bodies and hydraulic conditions, seismic surveys look at subsurface wave velocities and faults, and geotechnical surveys evaluate soil and rock properties for foundations—none of these map surface landforms for site selection in the same direct way.