2.1 Assessing Site Risks Flashcards
Two main risks to assess on site
Flooding and Fire
How to assess flood risk on a site?
Historical records, fema maps, other topo surveys. Walk the site & note water damage on structures, earth form that has been shaped into benches
Things that cause fire risk
- Degree of development
- Fuel loading (type and condition of vegetative cover, forest/understory structure)
- seasonal weather patterns (rain, wind)
- slope - steep slopes are much higher risk
- Aspect
- Low Accessibility to fire protection assistance
What slopes are at higher risk for fire danger?
Steep slopes because of wind acceleration, and harder access for fire crews
What aspect increases fire risk?
Slopes that are dry, due to southern or western exposure, or exposed to heavy dry winds - especially if found upslope
Types of landslides
- Falls: Rocks falling or rolling off ledge or slope
- Rock Slump: concave surface, material moves along identifiable surface
- Lateral spread: fractured masses move laterally
- Debris flow: material moves as liquid often saturated with water
- Soil Creep: slow imperceptible movement
A bank that rises vertically or overhangs the stream. This type of bank generally provides good cover for macroinvertebrates and fish and is resistant to erosion. However, if seriously undercut, it might be vulnerable to collapse.
Undercutting
Most hazardous type of material for landslides?
Granular loose materials
soil and debris that accumulate at the base of a slope by mass wasting or sheet erosion. Indicates history of past landslides
Colluvial Soils
Soils deposited by surface water. You’ll find them along rivers, in floodplains and deltas, stream terraces, and areas called alluvial fans.
Alluvial Soils
Previously developed or mined areas which may be contaminated with
pollutants.
Brownfields
underused real estate assets or land; typically does not require remediation in order to unlock value to an investor. Previously developed urban land
Grayfields
removal of a problem especially public health and safety risk. Ex: allows for removal of a site improvement not allowed by code.
Abatement