Snow Movement Research Articles

A Robust Video-Based Algorithm for Detecting Snow Movement in Traffic Scenes

Video-based Automatic Incident Detection (AID) systems are widely deployed in many cities for detecting traffic incidents to provide smoother, safer and congestion free traffic flow. However, the a...

Simple Snowdrift Model for Distributed Hydrological Modeling

A simple snowdrift model was developed, incorporated into a distributed winter-time hydrological model, and tested against snow measurements from a hillside in eastern Washington State. Snow movement can be an important factor in the distribution of spring soil moisture and runoff. Although current hydrological models often attempt to account for heterogeneities in precipitation distribution, they do not account for snowdrift. Snow melts and accumulates during the same times that it is redistributed. Therefore, evaluation required a snowmelt/accumulation model to be coupled with the snowdrift model. The snowmelt/accumulation model used the standard energy balance approach and performed well, i.e., standard errors of snow water equivalent '1 cm. The snowdrift model's simulated snow distribution generally agreed with observed snow distribution across a hill. Most notable were the model's ability to correctly place a snowdrift on the lee side of the hill and its ability to predict snow removal from nondrift areas. The effects of snow redistribution and the model's ability to reproduce these were obvious when overlaid on model results that ignored snowdrift.

Snowpack changes around a nickel–copper smelter at Monchegorsk, northwestern Russia

Snow depth in industrial barrens adjacent to the nickel–copper smelter at Monchegorsk (Kola peninsula, northwestern Russia) by the end of the winter was reduced to one-third of the depth observed in weakened and healthy forests located 30–65 km from the smelter; this reduction was due to both decline (by one-half) in the amount (mass) of snow and increase in snow density. Since winter precipitation in Monchegorsk was about the same as in an unpolluted locality 56 km south-southwest of the smelter, and snowpack characteristics correlated with site-specific wind speed, the low amount of snow around the smelter is presumably due to snow movement from open windy habitats and enhanced snow evaporation during the wind transport; higher snow densities may be explained by wind-induced compaction of snow particles. Pollution affects snowpack characteristics by modifying wind regime via forest damage; in turn, decline in snow depth influence the growth form and (possibly) performance of trees that managed to survive in heavily polluted habitats. Thus, initial (partially pollution-induced) forest disturbance, through secondary effects, may enhance further disturbance in a positive feedback fashion; therefore, possible ecological effects of pollution-related snowpack changes should be accounted for in field studies conducted along pollution gradients within the forest zone.

Cluster afforestation for creating diverse mountain forest structures — a review

A clustered arrangement of trees may be most appropriate in high elevation afforestation in order to take into account the variety of favourable and unfavourable microsite conditions and to create diverse stands with different tree species and a pattern of clusters and gaps. Long-term studies of the ecology of subalpine afforestations have shown that the young trees tend to be threatened over decades by fungal diseases, browsing ungulates, adverse climatic conditions, and snow movements. The intensity, duration and scale of the threats, however, varies greatly according to tree species and microsites. Based on these ecological findings, favourable and unfavourable microsites are described. An adapted system of clustered afforestation (in German: Rottenpflanzung) has been developed and tested. On favourable microsites, ‘small collectives’ were densely planted with 20–30 trees of one species on the assumption that the crowns of the trees within these small collectives would close within 5–10 years. Three to six small collectives were arranged in such a distance that they would merge into a larger tree ‘cluster’ (in German: Rotte) after a few decades. The distance between the tree clusters was kept large enough to ensure they remained separate throughout stand development. Such stands of clusters and gaps are expected to be, when mature, more resistant to high winds and heavy snow loads and less threatened by insects than uniform stands. They should be able to contain extensive inner margins permanently, and to be pervaded by light and warmth. Cluster planting on favourable sites can be used to minimise seedling mortality and is therefore the best strategy for afforestation at higher elevations.

Über glaziale Erosion und Übertiefung

Abstract. Glacial erosion and overdeepening is - as can be shown by the longitudinal profile of every valley formed by glaciers - not a process active on the whole longitudinal extension of the glacier in the same way, but is characterized by marked discontinuities. The reasons have been discussed for nearly a century, but the problem remained unsolved until now. It can - as H. Louis (1952) has demonstrated - be solved only when the motion mechanism of the glaciers is known. The present paper demonstrates on the base of observations in the area of the Iller glacier of the last glaciation that Pleniglacial glaciers with positive mass budget (advancing glaciers) have moved in another way than present-day glaciers with their - mostly - negative mass budget. Furthermore it is demonstrated that this particular motion mechanism can actually be observed at advancing outlet glaciers of the Vatnajökull in Iceland. It is characterized by a summation of numerous push movements of flat ice-shields on shear-planes over stagnant-ice of preceding advances, all of them of relatively short duration and range. They originated in precipitation-caused mass surpluses in the feeding area. This motion mechanism implies that an impact on the underground is possible only where (and when) the glacier advances beyond its stagnant-ice basement, i. e. immediately behind the front of the advancing glacier. A larger amount of glacial erosion can be expected only when the glacier after the advance remained in the maximum position reached for a longer time and, additionally, (snow)meltwater under hydrostatic pressure could affect the underground. Further observations on meltwater movement within the glacier are presented from Iceland, on meltwater impact on the underground (mainly) from the German Alpine Foreland. To sum up, the discontinuities of glacial erosion and overdeepening can be explained by the motion mechanism of advancing glaciers described, the protective effect of the overridden stagnant-ice basement of preceding advances, and the characteristic movement of (snow)meltwater in, below and along the glacier. Because the erosion processes described take place (mainly) immediately behind the front of the advancing glacier, they are a phenomenon restricted in space as well as in time, but therefore must be of extraordinary intensity.

Survival strategy of hiba (Thujopsis dolabrata var. hondae) and two broad-leaved trees in northern Japan in response to creep and glide pressures of snow.

We compared the tolerance of hiba (Thujopsis dolabrata var. hondae Makino), beech (Fagus crenata Blume) and oak (Quercus serrata Thunb.) to creep and glide pressures of snow. The top/root (T/R) ratio of hiba trees ranged between 7.1 and 41.4 compared with 3.6-10.9 and 1.0-12.4 for beech and oak, respectively. However, if prostrate stems bearing adventitious roots were included in the root component, the T/R ratio of hiba trees was comparable to the range observed for the co-occurring broad-leaved species (1.2 to 3.9). The adventitious roots originating from the trunks of hiba trees extended horizontally during the early growth stage. However, when stem diameter at ground level reached 6-7 cm, some large-diameter adventitious roots developed vertically to form, so-called, sustentacular roots. Because all of the dead hiba trees that we examined lacked sustentacular roots, we conclude that sustentacular roots are necessary to enable young hiba trees to withstand the pressures of snow movement. All of the large beech trees formed sustentacular roots and no dead beech trees were observed. Not all the oak trees formed sustentacular roots, which may explain why this species was found only on gentle slopes.

Observations of Slushflows and their Geomorphological Effects in the Swedish Mountain Area

In the Swedish mountains, the rapid mass movement of water-saturated snow, constituting slushflow or slush avalanche, occurs primarily along small streams at the time of break-up and spring warming. This process is an important geomorphic agent as well as a considerable hazard during the snowmelt season. Unlike snow avalanches, slushflows are of importance also in areas with gentle relief. Field criteria indicating slushflow hazard are bluish colour and tension cracks in the snowcover at potential starting zones.Terrain locations subject to slushflow activity can often be identified by evaluation of geomorphological features, e.g. veneers of rock debris, various erosion marks or medium-scale landforms such as slushflow fans or boulder tongues. Related processes that need to be clearly distinguished from slushflows are channel-confined wet-snow avalanches, debris flows, flash floods and river break-ups. The corresponding sedimentary deposits can be similar and correct identification may demand careful field evaluation of the mode of sedimentation or of the source area and track of the process involved.

Movement of Melting Snow on the Ground and Prediction of Landslides

It has been found that many landslides occur in snowy areas. According to our researches, the relation has been found between the occurrence of landslides and the depth of snowcover. In order to clarify this phenomenon, an automatic observation apparatus was introduced and an artificial landslide was produced. It was suggested that the landslide would be predicted by the investigation of constant strength c and φ of clay in the sliding zone, the behavior of the compound shearing force depending on the gap hydraulic pressure and the pressure of the air enclosed in the ground, and the worsening of sliding zone of permeability.

The movement of snow on the rapid slope and the effect of wood for it

The movement of snow on the rapid slope and the effect of wood for it