ESS 315 – Tiffany Litz

Will lead to loss of $$$s.

Can lead to loss of lives.

Avoidable messes

Slopes are often located on coastal properties and offer beautiful views

Despite risks, houses in these areas will always be desired.

The Seattle area has many unstable slopes that are prone to movement and slides.

https://myapa.planning.org/Landslides/Images/Landslides_Animation.gifLandslide in an area that has a retaining

wall

Careful planning is necessary to find the best solution for each slope.

Creep - Slow and steady downward movement of a slope. Indicated by curved tree trunks, bent fences or retaining

walls, tilted poles or fences, and small soil ripples or ridges

Rockslide - Rock mass that suddenly detaches and falls from the top of a steep slope Causes = gravity or freeze/thaw action

Mudslide – Sudden flow of mud down a slope Occurs when soil becomes suddenly saturated (in storms,

snow thaw, floods, etc)

Earthflow – The upper section of a sloping water-soaked terrain that collapses, forming a tongue of land the length of the slope.

The effort to reduce the impact of land movement for people and their property. can be used to strengthen roads, bridges, and

other critical facilities. guide local decision makers in their involvement

with land use and development issues.

Four types:

Altering - Modifying the hazard involves eliminating or reducing the frequency of its occurrence. Stabilizing stream banks from continued erosion is an example.

Averting - Redirecting the impact away from a vulnerable location by using structural devices or land treatment can shield people and development from harm. Retaining walls and diverting runoff represent physical efforts implemented to keep the risk away from the people.

Adapting – Modifying structures and altering design standards of construction. Pre-identified landslide hazards require special building standards and construction practices in order to reduce vulnerability to damage.

Avoiding-- Keep people away from the hazard area or limit development in a risk area. Enforcement actions such as zoning regulations, building codes and ordinances are intended to restrict, limit or deny access to specially identified risk areas.

Terracing:

Retaining Wall

Mulching and Adding GroundcoverMulch protects against rain and wind, and reduces loss of

soil moisture during extended dry periods.

Soil Redistribution

Deflecting Wall

Shotcrete:reinforces the strength of the rockface

Drape Mesh:reinforces the strength of the rockface

http://www.terraerosion.com/projects/slope-stabilization.htm

http://www.ecy.wa.gov/programs/sea/pubs/93-30/vege01.html

http://landslides.usgs.gov/recent/archives/1997seattle.php

http://extension.missouri.edu/publications/DisplayPub.aspx?P=G1509

http://pubs.usgs.gov/of/2004/1396/1396.gif http://www.seattle.gov/DPD/Landslide/Study/

part1.asp http://faculty.washington.edu/tswanson/ESS/

315/Student%20PP%20Presentations/sloperemediation.ppt