Geomorphic Methods for Interpreting Remotely Sensed Data: A Slope Hazard Case Study in Minnesota
Abstract
WSB partnered with the City of Burnsville, Minnesota, to implement a slope vulnerability risk assessment for slopes in the City. The program has five phases: Identification, Field Assessment, Risk Estimation, Mitigation, and Long-term Monitoring.
For Phase 1: Identification, the geohazard team applied a GIS-based geostatistical model originally designed for the Minnesota Department of Transportation along trunk highways. The model identifies historic slope failures in the study area and uses geostatistical methods to determine the most likely geomorphic factors associated with these failures. Finally, the model uses this information to predict future failures throughout the City. Phase 2: Field Assessments, was used to verify model results and gather information on anthropogenic impacts to slope vulnerability, as well as begin assessing potential mitigation methods. Phase 3: Risk Estimation was a collaborative process between WSB, City officials, and emergency response professionals. A risk matrix was developed that uses the probability of slope failure (determined in Phases 1 and 2) and the direct consequence of that slope failure to find total risk (i.e. risk= probability x consequence). Some consequences included impacts to gas pipelines, emergency response routes, and high-density residential structures. The combination of probability of failure multiplied by the consequence allowed us to group each slope into defined and easy to understand categories. The four categories were Management Required, Further Study, Monitoring, and No Action. Currently, the City is conducting Phase 4: Mitigation. The risk estimation process identified 12 slopes that should be prioritized for mitigative action. As a direct result of this work, the City was able to identify and begin improvements on specific slopes that have the highest likelihood to impact the interests of stakeholders. One specific example of involved the installation of a catch basin to reduce the amount of runoff flowing over the slope. The slope vulnerability risk assessment has helped to reduce risk within the City to residents and municipal infrastructure.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMNH12A..04R
- Keywords:
-
- 4313 Extreme events;
- NATURAL HAZARDS;
- 4332 Disaster resilience;
- NATURAL HAZARDS;
- 4337 Remote sensing and disasters;
- NATURAL HAZARDS;
- 4342 Emergency management;
- NATURAL HAZARDS