Unit 5: Mitigating future disasters: developing a mass-wasting hazard map
This unit serves as the summative assessment of the Surface Process Hazards module. In September 2013, the Boulder area of Colorado experienced an extreme rain event that led to mass wasting in many areas. This has led to greater scrutiny of landslide hazards in the area. In this case study of the Boulder Creek catchment, students act as scientists, using geologic, climate, and anthropogenic data to evaluate an area's vulnerability to mass wasting and potential societal impact. They use aerial imagery, topographic maps, bedrock and surficial geologic maps, slope/aspect maps, hillshade imagery, stream maps and population-density maps to evaluate mass-wasting hazard and risk in the Boulder Creek, Colorado, watershed. Using what they have learned about landscape-feature recognition, factors that contribute to mass wasting, and the impacts of mass wasting, they construct a hazard map for the study area and consider the impacts of a mass-wasting event on the area's inhabitants.
Unit 5 Learning Outcomes
This unit is intended to provide the summative assessment for the entire module. Students should demonstrate a mastery of the learning goals for the entire module. The Module Goals are:
- Students will use geodetic data to analyze landscape characteristics and use them as indicators of mass wasting hazards
- Students will articulate the societal effects of mass wasting events and consider the role of natural and human-caused changes in the mass wasting potential for a given landscape.
Context for Use
Unit 5 is the summative assessment for the Surface Process Hazards module. Unlike Units 1–4, which can be implemented individually, Unit 5 is appropriate for faculty who have implemented a portion or all of the Surface Process Hazards module and are interested in assessing the overarching module goals. If the module will not be implemented in its entirety, we suggest the implementation of Unit 2: Reading the landscape and Unit 4: Anatomy of a tragic slide—Oso Landslide case study prior to conducting the summative assessment to ensure that students are familiar with the imagery used in Unit 5 and have investigated the environmental and built characteristics that contribute to mass-wasting susceptibility of a particular study area. Users may choose to implement Unit 5 as an individual in-class exercise or as an out-of-class assignment. Group collaboration is also a possibility, although if the user's primary aim is summative assessment of individual students, the work should be completed separately by each student.
Description and Teaching Materials
This unit is the module summative assessment. Students will be given maps similar to those used in Units 2–4, for the Boulder Creek watershed of Colorado. In Part 1, students will synthesize the data from all of the available maps to analyze the mass-wasting hazards in the region. This part can be completed during class time. In Part 2, students will prepare a written report outlining and providing evidence for their interpretation of what mass-wasting hazards are present in the region. Their reports should also summarize potential hazard preparation or mitigation procedures that they suggest for the region, based on a review of existing guidelines for other regions. In Part 3, students reflect on how their thinking has evolved over the course of the module and how that might influence future actions. Part 3 can be completed at home and turned in with the rest of the report.
- Unit 5 Student Instructions for Final Hazard Map & Report (Microsoft Word 2007 (.docx) 351kB Jun22 17)
Unit 5 Student Instructions for Final Hazard Map & Report PDF (Acrobat (PDF) 373kB Jun21 17)
Students will be given regional map data (as both kmz and pdf): aerial, topography, geology (bedrock/surficial), slope, aspect, hillshade (both SRTM regional and local lidar), streams, and population density. Students may also be given some or all of the questions below to guide their synthesis of the map data. Students will annotate the lightened hillshade image to produce a hazards map for the Boulder Creek watershed (and downstream region) similar to that produced in Unit 3. When constructing the maps, remind students to consider potential direct and indirect effects of mass wasting.
- Does the USGS suggest this region has a high, medium, or low seismic-hazard potential?
- Does this region receive a lot of precipitation? Does it fall during the entire year or more seasonally? Is some of the precipitation stored as snow?
- Are stream valleys confined or do they meander across a flat landscape. Imagine what the streams might look like in flood stage.
- Are there locations where slopes have been locally steepened or otherwise modified either naturally (e.g. undercut by stream) or as a result of human modifications to the landscape (e.g. road-cut, mining, etc.).
- Might the underlying regional geology (bedrock and surficial) increase the mass-wasting potential in any part of this region?
- Is there evidence from geodetic data for mass redistribution in this landscape?
- Are there any residential areas or places that people congregate in regions with high potential for mass wasting?
- Are there any residential areas or places that people congregate in regions downstream of regions with high potential for mass wasting?
Boulder Creek Maps
- Poster format
- Google Earth format—similar maps Unit 5 Google Earth Version Maps (Zip Archive 25MB May18 16)
Students will prepare a written report (~2 pages plus one map) summarizing their map interpretation and potential for societal planning. The first page of text should be dedicated to the factors raising the potential for mass wasting in specific locations within this landscape. Students will cite evidence from the different types of landscape data to support their map interpretations. Students will consult online resources (examples listed below) to review how other regions have prepared for mass-wasting events. In the second page of text, students should describe how towns and citizens in this region might prepare for future mass-wasting events. Students will reference planning techniques used in other towns.
Students are asked to write a half-page reflection on (1) how their perception and understanding of these hazards has evolved and (2) how that might affect their actions/thinking in the future. They are required to draw on supporting evidence from their experience for what they say. This process of reflection (or metacognition) is very important for long-term learning and application of knowledge. More information on metacognition is at InTeGrate Project's Metacognition page and Teaching Metacognition by the Cutting Edge Project.
Teaching Notes and Tips
- Unit 5 can be implemented as an in-class exercise or a homework assignment/project to be completed outside of class.
- Regardless of the format of implementation, it is important to convey to students the importance of linking every one of their rankings (high, moderate, low mass-wasting susceptibility) that they designate on their map with specific lines of evidence from the datasets provide. You could introduce the exercise by working with students to establish which criteria they will use to designate an area as high, moderate, or low. You may also wish to select a small area (where the mass wasting susceptibility ranking is relatively straightforward) and walk through an example with students where they designate the area as low, moderate, and high susceptibility and provide specific evidence from the maps to support their interpretation.
- Although maps may be provided to students electronically, hard copies may be most conducive to students using multiple lines of evidence to support their analysis of mass-wasting susceptibility.
Unit 5 Final Report example rubric (Microsoft Word 2007 (.docx) 128kB Jun22 17)
References and Resources
- Level 3 supplemental data: Basin-averaged erosion rate and lidar-differencing data are available from: Anderson, S. W., Anderson, S. P., and Anderson, R. S., 2015. Exhumation by debris flows in the 2013 Colorado Front Range storm, Geology, v. 43(5).