Assessing the application of a laser rangefinder for determining snow depth in inaccessible alpine terrain

Abstract

Abstract. Snow is a major contributor to stream flow in alpine watersheds and quantifying snow depth and distribution is important for hydrological research. However, direct measurement of snow in rugged alpine terrain is often impossible due to avalanche and rock fall hazard. A laser rangefinder was used to determine the depth of snow in inaccessible areas. Laser rangefinders use ground based light detection and ranging technology but are more cost effective than airborne surveys or terrestrial laser scanning systems and are highly portable. Data were collected within the Opabin watershed in the Canadian Rockies. Surveys were conducted on one accessible slope for validation purposes and two inaccessible talus slopes. Laser distance data was used to generate surface models of slopes when snow covered and snow-free and snow depth distribution was quantified by differencing the two surfaces. The results were compared with manually probed snow depths on the accessible slope. The accuracy of the laser rangefinder method as compared to probed depths was 0.21 m or 12% of average snow depth. Results from the two inaccessible talus slopes showed regions near the top of the slopes with 6-9 m of snow accumulation. These deep snow accumulation zones result from re-distribution of snow by avalanches and are hydrologically significant as they persist until late summer.

Measurement of the physical properties of the snowpack

“…Hood and Hayashi [] used a handheld laser rangefinder with a 0.905 μm wavelength, finding that snow depth in complex mountain terrain could be measured with an accuracy of 12% compared to manual depth measurements. Due to the similarity of laser ranging to monopulse sonar and radar, the same limitations related to pulse width is also present in the application of this method.…”

“…Due to the similarity of laser ranging to monopulse sonar and radar, the same limitations related to pulse width is also present in the application of this method. The use of a laser rangefinder allowed Hood and Hayashi [2010] to measure the rate of snow ablation at a site where manual snow depth measurements could not be made, thereby gaining insight into the hydrologic response of an alpine watershed.…”

Using a fixed-wing UAS to map snow depth distribution: an evaluation at peak accumulation

“…Existing techniques include terrestrial or airborne laser scanning (e.g., Hopkinson et al, 2004;Deems et al, 2006Deems et al, , 2013Prokop et al, 2008;Dadic et al, 2010;Grünewald et al, 2010Grünewald et al, , 2013Lehning et al, 2011;Hopkinson et al, 2012;Grünewald and Lehning, 2015;Hedrick et al, 2015), SAR (synthetic aperture radar, Luzi et al, 2009), aerial photography (Blöschl and Kirnbauer, 1992;König and Sturm, 1998;Worby et al, 2008), time-lapse photography (Farinotti et al, 2010), and optical and micro-wave data from satellite platforms (Parajka and Blöschl, 2006;Dietz et al, 2012). The good performance of these methods has been widely discussed, but survey expenses are still a constraint (Hood and Hayashi, 2010). Recently, digital photogrammetry has emerged as a cheaper tool to perform these surveys: as an example, Nolan et al (2015) have evaluated this methodology in three study cases in Alaska and have compared airborne measurements of snow depth with ∼ 6000 manual measurements.…”

Influence of groundwater spring discharge on small‐scale spatial variation of an alpine stream ecosystem

“…The site is in the alpine zone of the Opabin sub-basin at an elevation of approximately 2220 m a.s.l. Average annual temperature and precipitation are estimated as 1°C and 1000-1200 mm, respectively (Hood and Hayashi, 2010). The bedrock in this watershed is composed primarily of thickly bedded quartzite and quartzose sandstone, with interbedded shales, of the Cambrian Gog Group.…”