Snow Supply Research Articles

МЕЗОТРОФНЫЕ ДОЛИННЫЕ БОЛОТА НА СЕВЕРНОМ МАКРОСКЛОНЕ ЦЕНТРАЛЬНОГО КАВКАЗА

Alpine swamps, among other wetlands, are of particular interest due to their relict nature, some peculiarities of their origin, functioning and dynamics, as well as due to their poor knowledge. The object of our study was a cascade swamp complex, consisting of three communicating baths and a lake, located at different heights in the Karasu river valley, in Upper Balkaria at an altitude of about 2 thousand meters above sea level. On the basis of our field descriptions, an analysis of the relief and vegetation of the mesotrophic and lowland bogs which constitute the complex was carried out. It was revealed that the basis of the plant communities of mesophytic segments is sphagnum and three types of sedge (marsh, urchin-hairy, and spout). There are communities of subalpine meadows and forests on the slopes around the wetland complex. It is assumed that the complex has some underground supply, in addition to rain and snow supply and runoff from the neighboring mountain massif.

РЕГІОНАЛЬНА МЕТОДИКА ДЛЯ ВИЗНАЧЕННЯ МАКСИМАЛЬНОГО СТОКУ ВЕСНЯНОГО ВОДОПІЛЛЯ РІЧОК CУББАСЕЙНУ Р.ДЕСНА В УМОВАХ ЗМІН КЛІМАТУ

The results of development of the regional methodology for calculating the maximum water runoff of the rare probability of exceedance for the rivers of the sub-basin the Desna River under the conditions of modern climate change are presented. As basic for calculation authors used a modern modified version of the operator model of runoff formation developed at the Odessa State Environmental University to determine the characteristics of spring flood, which allows taking into account the influence of climate change on the calculated characteristics of the maximal runoff modules. The advantage of the proposed method is that it is based on the theory of channel isochrones, which allows describing the natural process of formation of runoff in the form of the operator “slope tide – channel runoff”. To substantiate the basic calculation parameters of the author’s methodology, was used the data of direct observations on the hydrological characteristics of the maximum waterrunoff of the spring flood (water discharges, depth of runoff and duration of the influx) and meteorological factors of its formation (maximum snow supply and precipitation during spring flood) for the period since its beginning to 2015, including. In the process of standardization of the main components of the proposed methodology, methods of statistical processing, spatial generalization, numerical problem solving and mathematical modeling were used. To account for possible climate change, the original author’s scientific and methodological approach is proposed, which is to determine “climate corrections” on the basis of modern baseline data – maximum of the water snow supply and precipitation during spring flood and runoff coefficients of the water, taking into account their dependence from long-term annual air temperatures that are projected according to the developed climate models and scenarios. The modified version of the operator model is proposed to be used as a regional calculation technique for determining maximum runoff modules of the rare probability of exceeding for ungauged rivers in the Desna sub-basin during the passage of the spring flood.

Assessing the Sustainability of Ski Fields in Southern Japan under Global Warming

This is the first study in assessing the impact of climate change on Japanese ski fields with ensemble dynamical downscaling simulations. We target three ski fields in Ehime Prefecture, a southern border area for skiing in Japan. Our field survey revealed that a field located above 1200 m altitudes currently operates on natural snow supply, but those located at lower altitudes depend solely or partially on artificial snow supply. Fields are currently open for 82∼105 days. We analyzed ensemble high-resolution (5 km) dynamical downscaling simulations for future ski season durations with natural and artificial snow supplies. The future projection results for the end of the twenty-first century suggested that there would be virtually no natural snow accumulation in the study area for skiing. With artificial snow supply, a field located above 1200 m would be able to retain more than two months of ski season duration. Fields located at lower altitudes would only be able to open for 37∼43 days even with artificial snow supply. While the above projections suggest a severe outlook for the targeted ski fields, it is important to note that there is a strong demand from local skiers at beginner/intermediate levels for these ski fields. Thus, as long as these demands remain in the future, and if a business model to maximize profit during short opening periods is established, it may be possible to offset profit loss due to climate change.

The Desna River Daily Multi-Site Streamflow Modeling Using SWAT with Detail Snowmelt Adjustment

The Ukrainian Government started the process of EU water Directives implementation aimed at developing of the River Basin Management Plan for 9 main river catchments. The program SWAT was tested to simulate the water flow of a large plain river with a predominant snow supply. River discharges (12 gauges), snow cover depth (13 stations), and the soft data, including graphically defined surface runoff and MODIS evapotranspiration, were used to calibrate the model. The calibration flowchart, along with a detailed source data description, is proposed to aid with streamflow simulation for the snowmelt-driven watersheds and fill the existing gap of distributed hydrological modeling in the region. The main issues with snow simulation and climate data coverage are discussed. The program SUFI-2 in SWAT-CUP package was used for performing calibration/validation and uncertainty analysis. The statistics (R2, NSE, PBIAS) showed good agreement (NS > 0.7, R2 > 0.75, PBIAS < ±10%) for a major part of the gauges and satisfactory for all of them (NS > 0.5, R2 > 0.6, PBIAS < ±15%), except of two linked upstream outlets. This study provides the basis for further research on water resources, the impacts of climate change, and water quality issues.

Peculiarities of annual internal distribution of small rivers’ runoff (on example of the Udy river)

Formulation of the problem. Water is the basis of life and, therefore, the questions regarding the definition of annual runoff distribution as a whole in Kharkiv region and in the context of individual river basins remain actual. The study of the domestic annual runoff is due to the fact that the Udy River basin belongs to the poorly watered areas, and in recent years climate change leads to a decrease in drainage during the year, including seasonal runoff changes, which may cause water supply problems in the economic sphere. The purpose of the article is to study modern features of the annual distribution of the water runoff of the Udy River basin. Presenting main material. The article deals with the peculiarities of the formation and changes in the annual flow of the river Udy basin for 35 years (1991-2015). Having analyzed the average monthly water consumption in the Udy basin, it can be noted that the annual distribution of drainage for this period is close to all rivers - typical spring flood (March), summer (August, September) and winter (December, January) months. However, the share of spring water in the Udy basin in the annual volume of drainage has decreased and the supply of rivers has changed. In connection with climatic changes, namely, the decrease in winter rainfall, there was an increase in the share of underground supply which contributed to its alignment with the share of snow intra-annual distribution. Conclusions. Having studied annual distribution of the river basin’s flow in the Udy River, it has been found that the share of spring water in the annual volume of drainage decreased from 42-36 to 36-25 %. In recent years, there has been less precipitation in winter and, therefore, snow supply is not prevailing, and there is an increase in the share of underground supply.

Climate change threats to one of the world’s largest cross-country skiing races

This study investigates the relationship between climate variability and the participant cancellation ratio at one of the world’s oldest, longest and largest cross-country skiing races, the Vasaloppet. This race is held in the Swedish region of Dalarna on the first Sunday of March each year. Data are based on the number of registered and starting skiers and local weather conditions (natural snow supply and temperature) for the period 1951–2016. As the dependent variable is bounded between zero and one, the fractional logit model is employed. Estimations show that a lack of natural snow significantly increases the cancellation ratio. In particular, a decline in snow depth from the average level of 57 to 30 cm over the sample period leads to an increase of 3.3 percentage points in the cancellation ratio. Interestingly, the dependence on natural snow has declined in absolute terms in recent years due to various adaptation practices, such as snow storage and snow production.

Генезис максимумов водности рек и изменчивость водного режима в современный климатический период.

The article deals with the water regime of the Upper Don`s rivers in the current climatic period, comparing characteristics of 1939-1970, 1971-2000, 2001-2014. The features of the formation of flood peaks were identified. The spring flood caused by melting snow increased to about 10 days. The shortest period of spring flood on the Don River near the town of Liski lasted 41 days in 1961, and the longest – 78 days in 2001.The timing of the beginning of the spring flood has shifted toward earlier dates of its occurrence and the ending -to the side of later dates. With increasing total duration of spring flood on 15-20 days, the late onset of the highs was observed. Due to milder winters and reduction of depths of soil freezing on the pick of the spring flood, water on the slopes of the river filtered to a greater extent in the soil, than goes on the formation of slope runoff. And only during a more intense snowmelt and water flow in the riverbed is formed the maximum flow of floods. Temporal and spatial heterogeneity of the formation of maxima in the river system of Don and of Khoper were marked. In the upper reaches they represent two independent, isolated from each other zone of runoff formation. In the basin of the Khoper highs are formed later than in the Don`s basin. The emergence of the thaw in February is almost natural now. In February of 2016, with abnormal weather conditions, the boundary between the winter and spring seasons due to numerous thaws were conditional. The frequency of occurrence the bimodal spring floods in the basin of the Khoper has frequented. In 2010, the spring flood hydrograph had atypical ridged shape. Reduction of runoff of spring flood and its share in annual volume in this century up to 38-45 % in the rivers of the Central Russian upland on the right bank of the Don leads to a change in the priority of sources of supply. The dominant source of power for the rivers of the basin of the hopper remains the snow supply.

The potential for snow to supply human water demand in the present and future

Runoff from snowmelt is regarded as a vital water source for people and ecosystems throughout the Northern Hemisphere (NH). Numerous studies point to the threat global warming poses to the timing and magnitude of snow accumulation and melt. But analyses focused on snow supply do not show where changes to snowmelt runoff are likely to present the most pressing adaptation challenges, given sub-annual patterns of human water consumption and water availability from rainfall. We identify the NH basins where present spring and summer snowmelt has the greatest potential to supply the human water demand that would otherwise be unmet by instantaneous rainfall runoff. Using a multi-model ensemble of climate change projections, we find that these basins—which together have a present population of ∼2 billion people—are exposed to a 67% risk of decreased snow supply this coming century. Further, in the multi-model mean, 68 basins (with a present population of >300 million people) transition from having sufficient rainfall runoff to meet all present human water demand to having insufficient rainfall runoff. However, internal climate variability creates irreducible uncertainty in the projected future trends in snow resource potential, with about 90% of snow-sensitive basins showing potential for either increases or decreases over the near-term decades. Our results emphasize the importance of snow for fulfilling human water demand in many NH basins, and highlight the need to account for the full range of internal climate variability in developing robust climate risk management decisions.

Vegetation-Permafrost Relations within the Forest-Tundra Ecotone near Old Crow, Northern Yukon, Canada

Old Crow Flats is a 5600 km2 glaciolacustrine plain that straddles the forest-tundra ecotone in northern Yukon. Continuous taiga corridors occur in the entrenched river valleys, where annual mean ground temperatures (Tg) at the depth of zero annual amplitude at two locations were −3.1 and −4.0oC in 2013. On the Flats, the vegetation cover is patchy, and Tg varied between −5.1 and −2.6oC. Annual mean near-surface permafrost temperatures (Tps) measured on the Flats between 2008 and 2011 in patches of taiga, tall shrubs and low shrubs were correlated with local snow depth. Snow depth was controlled by vegetation height if the snow supply was not limited, for example, where low shrubs and large lakes dominate the landscape. In this setting, snow depths and, hence, Tps in taiga patches were higher (−2.6 to −2.9oC) than in the surrounding shrub vegetation (−3.5 to −5.5oC). Where taiga patches were more extensive, redistributed snow was trapped at the patch edge and Tps in taiga was lower (−4.1 to −4.3oC) than in the surrounding shrub patches (−3.2 to −3.6oC). The permafrost temperature field is heterogeneous under patchy vegetation in the forest-tundra ecotone. Our data suggest that it is governed by both the snow-holding capacity of local vegetation patches and the spatial configuration of vegetation in the surrounding landscape, which controls snow supply. Copyright © 2014 John Wiley & Sons, Ltd.

Hydrological effects of Norway spruce and European beech on snow cover in a mid-mountain region of the Polana mts., Slovakia / Hydrologický vplyv smreka obyčajného a buka lesného na snehovú pokrývku v stredohorských polohách pohoria poľana na slovensku

The paper evaluates the results of a 6-year-monitoring of the eco-hydrological influence of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus silvatica L.) forest stands on the hydro-physical properties of snow cover. The experiment was carried out in the artificially regenerated 20-25-year-old forest stands approaching the pole timber stage in the middle mountain region of the Polana Mts. - Biosphere reserve situated at about 600 m a.s.l. during the period of maximum snow supply in winters of years 2004 - -2009. Forest canopy plays a decisive role at both the snow cover duration and spring snow melting and runoff generation. A spruce stand is the poorest of snow at the beginning of winter. High interception of spruce canopy hampers the throughfall of snow to soil. During the same period, the soil surface of a beech stand accumulates greater amount of snow. However, a spruce stand accumulates snow by creating snow heaps during the periods of maximum snow cumulation and stand´s microclimate slows down snow melting. These processes are in detail discussed in the paper. The forest stands of the whole biosphere reserve slow down to a significant extent both the snow cover melting and the spring runoff of the whole watershed.

First cosmic ray exposure dating (in situ produced10Be) of the late pleistocene and holocene glaciation in the Nanhutashan Mountains (Taiwan)

In Taiwan, efficient climate-driven strong erosion processes are the leading cause for low preservation of geomorphic landforms. Despite the absence of present-day glaciers, glacial relicts have been reported in high altitude areas. These scarce landforms provide opportunities for reconstructing the timing of the last deglaciation in a region where glacial history is poorly documented. We have collected boulders and striated bedrocks in the Nanhutashan area and calculated surface exposure ages based on in-situ produced 10Be concentrations. The oldest glacial remains, dated at 11.1 ± 3.3 ka, correspond to the last glacial advance. The Holocene is characterized by a continuous retreat of the ice-cap until at least 7.2 ± 1.0 ka. Our results are in agreement with a scenario where changes of monsoon regimes lead to a strong reduction of the winter monsoon during the early Holocene, causing a decrease of snow supply and disequilibrium of the hydrological budget.

Magnitude and Frequency of Avalanches in Relation to Terrain and Forest Cover

This paper contains an analysis of magnitude and frequency of avalanches in relation to terrain and forest cover variables. The analysis was applied to 194 avalanche paths in four avalanche areas along highways in British Columbia with approximately 25,000 avalanches recorded. The magnitude and frequency for the avalanche paths were estimated from data collected along the highways by avalanche technicians. Results show that mean magnitude and mean frequency are weakly correlated for a set of avalanche paths in an avalanche area. In addition, with magnitude and frequency viewed as response variables, magnitude and frequency correlate with different sets of predictor variables from one area to another. This paper contains the first comparison of variables which correlate with magnitude and frequency from one avalanche area to another. The results show that previous studies conducted for single areas are simplistic. However, there is some consistency between areas. Avalanche frequency is most directly related to terrain steepness and snow supply. Average avalanche magnitude appears related to terrain steepness, starting zone, and track confinement and the scale (e.g., total vertical drop of the path) with only indirect evidence for a link to snow supply.

Characteristics of terrain, snow supply and forest cover for avalanche initiation caused by logging

AbstractThis paper contains statistical analyses of parameters to characterize starting zones of destructive avalanches which have resulted from clear-cut logging in British Columbia, Canada. Data from 76 avalanche sites in the Coast Mountains (western British Columbia) and the Columbia Mountains (eastern British Columbia) are analyzed. The parameters include a selection which characterize snow supply (related to potential avalanche frequency), avalanche magnitude and those which are known to affect avalanche formation including terrain features, vegetation density, vegetation height and ground surface roughness. The results provide the data framework for possibly preventing future disasters by altering logging plans.

Snow‐push processes in pronival (protalus) rampart formation: geomorphological evidence from smørbotn, romsdalsalpane, southern norway

It is demonstrated that pronival (protalus) ramparts can be formed by a snow‐push mechanism and need not accumulate in the conventional manner as a result of supranival processes. Ridges in pronival positions up to 1.2 m high and of unequivocal snow‐push origin are described from two sites in Smørbotn cirque, Romsdalsalpane, southern Norway. The seven lines of evidence are: (1) parallel abrasion tracks on large boulders embedded in the substrate; (2) displaced surface and embedded clasts with proximal furrows; (3) corrugated (flute‐like) substrate surfaces; (4) the sickle‐shaped plan‐form of the ridges; (5) generally asymmetrical ridge cross‐profiles (shallow, concave proximal; steep, convex distal); (6) strong preferred orientations and dips of surface‐embedded clasts on ridge proximal slopes; and (7) a subnival/pronival ridge comprising loosely packed diamicton forming along the contact zone between the snowbed and substrate. This evidence indicates ridge formation by snow sliding involving bulldozing of the substrate. Factors considered important in favouring snow push producing distinct pronival ramparts at the sites include: a maritime periglacial climate with heavy winter snowfall and rapid snow‐firn conversion producing snow densities of up to 900 kg m–3; a deformable substrate with relatively small inputs of rockfall or avalanche debris; and a steep headwall susceptible to snow avalanching and hence enhanced snow supply. Consideration is given to the prospect that larger pronival ramparts can form incrementally by a snow‐push mechanism.

Stratigraphic Studies and Surface-Layer Formation. A Case Study: Eastern Wilkes Land, East Antarctica (Abstract)

This paper presents the results of a detailed study on the geomorphic and diagenetic processes of surface-layer formation and its subsequent preservation in the stratigraphic record. The study supplemented stratigraphic studies carried out along a 750 km ANARE traverse route along the 69 °S parallel between 112° and 131 °E (which approximately follows the 2000 m contour) in the katabatic wind zone of eastern Wilkes Land.A 100 cane farm was established at GD03 (69 °S, 115°E; 1835 m a.s.l.), adjacent to a 30 m deep firn-core drill site. The cane farm was used to monitor seasonal changes in snow accumulation and the type, size, distribution and orientation of the surface micro-relief.The annual snow accumulation at GD03 is equivalent to 300 kg m−2 of water. This annual layer is visibly marked by a multi-layered ice crust, typically 1–2 mm thick, which is formed in autumn during a hiatus in snow supply. Within the annual layer, single-layered thin ice crusts were observed. These correspond to short hiatus periods, of the order of 2–3 weeks, during late winter–early spring, and radiation glazes formed during summer.Density and oxygen-isotope–depth profiles display annual cyclicity within the snow-pack. Considerable horizontal variation was found in a single annual-layer thickness, with respect to ice-crust thickness, snow-density and oxygen-isotope values, and depth-hoar development, when traced in 21 2 m cores drilled at 5 m horizontal spacing.The observed changes in surface micro-relief distributions over the cane farm have enabled a greater understanding of vertical variations between annual layers observed in the 30 m firn core.

Stratigraphic Studies and Surface-Layer Formation. A Case Study: Eastern Wilkes Land, East Antarctica (Abstract)

This paper presents the results of a detailed study on the geomorphic and diagenetic processes of surface-layer formation and its subsequent preservation in the stratigraphic record. The study supplemented stratigraphic studies carried out along a 750 km ANARE traverse route along the 69 °S parallel between 112° and 131 °E (which approximately follows the 2000 m contour) in the katabatic wind zone of eastern Wilkes Land. A 100 cane farm was established at GD03 (69 °S, 115°E; 1835 m a.s.l.), adjacent to a 30 m deep firn-core drill site. The cane farm was used to monitor seasonal changes in snow accumulation and the type, size, distribution and orientation of the surface micro-relief. The annual snow accumulation at GD03 is equivalent to 300 kg m−2 of water. This annual layer is visibly marked by a multi-layered ice crust, typically 1–2 mm thick, which is formed in autumn during a hiatus in snow supply. Within the annual layer, single-layered thin ice crusts were observed. These correspond to short hiatus periods, of the order of 2–3 weeks, during late winter–early spring, and radiation glazes formed during summer. Density and oxygen-isotope–depth profiles display annual cyclicity within the snow-pack. Considerable horizontal variation was found in a single annual-layer thickness, with respect to ice-crust thickness, snow-density and oxygen-isotope values, and depth-hoar development, when traced in 21 2 m cores drilled at 5 m horizontal spacing. The observed changes in surface micro-relief distributions over the cane farm have enabled a greater understanding of vertical variations between annual layers observed in the 30 m firn core.