Item: SLOPE MEASUREMENT FOR HUMANS: INCLINOMETER ERROR AND RISK COMMUNICATION
-
-
Title: SLOPE MEASUREMENT FOR HUMANS: INCLINOMETER ERROR AND RISK COMMUNICATION
Proceedings: International Snow Science Workshop Proceedings 2023, Bend, Oregon
Authors:
- Ian McCammon [ Salt Lake City, UT, USA ]
Date: 2023-10-08
Abstract: Inclinometers are key tools for assessing risk in avalanche terrain, and a wide variety of devices and methods are in use across the avalanche community. But how accurately can this community actually measure slope steepness? This study found that, under ideal conditions, currently available inclinometers have a profile measurement accuracy of about +/- 4 degrees. This measurement uncertainty, when combined with start zone avalanche frequency and slab extension effects, can result in significant unintended exposure to avalanche risk. Exposure amplification can be four-fold or greater on critical slopes around 30 degrees and above. These effects can be partially mitigated by making multiple independent measurements of a subject slope in order to reduce, but not eliminate, risk errors. More robust risk mitigation can be obtained by de-emphasizing precise slope angles in favor of communicating color-coded slope angle ranges and associated action standards for those ranges. A specific construct with boundaries at 20 degrees and 30 degrees is shown to quantitatively align with decision strategies most likely employed by individuals who seek out particular ranges of slope angles, and guide users to more robust, error-tolerant management of backcountry avalanche risks.
Object ID: ISSW2023_O12.05.pdf
Language of Article: English
Presenter(s): Ian McCammon
Keywords: slope measurement, slope angle, inclinometer, error, start zone, risk communication, decision making
Page Number(s): 1141 - 1148
-