Lesson · Geotechnical & Slope Stability

Assessing Slope Risk Where You Live

How to read a geohazard susceptibility map against your own address, what the categories mean in practice, and the limits of a map drawn at regional scale.

  • Professional
  • Teacher
  • Institution
  • Responder

Learning objectives

  • Locate an address on a geohazard susceptibility map and read its assigned category.
  • Explain what susceptibility means and why it is not a prediction of when.
  • Describe why regional-scale mapping can miss site-specific hazards.
  • Identify which land-use changes raise susceptibility on an already marginal slope.

In the field

Ordered, and meant to be workable under pressure. Numbered because the sequence matters.

  1. Obtain the geohazard map covering your locality from the issuing bureau rather than a third-party copy.
  2. Mark your building, your school, and your evacuation route on it.
  3. Note the map scale and treat anything smaller than its resolution as unassessed.
  4. Document cut-and-fill, vegetation removal, or drainage changes near the slope since the map was drawn.
  5. Escalate a site-specific assessment through local government where the map and what you see disagree.

Sources · 3

The tag under each source states what was actually checked. “Authority named · URL not re-resolved” means the issuing body and document are named, but the link was not re-resolved for this lesson. It is not a claim of verification, and the authority’s own current bulletin always supersedes anything here.