High Alpine Valley Research Articles

Glaciers and mass movements in the Hüttwinkl Valley (Hohe Tauern range): from the Last Glacial Maximum (LGM) until now

Abstract. The Hüttwinkl Valley, the uppermost section of the Rauris Valley, offers a unique sedimentary and morphological archive to study the development of the landscape in a high-Alpine valley since the Last Glacial Maximum (LGM). Glacial extents of the past, especially during the Younger Dryas (12.8–11.7 ka) and the Little Ice Age, as well as the present-day massive glacier retreat, are clearly recorded. On the other hand, the effects of different mass movements on valley development are evident. The field trip begins in Kolm-Saigurn, where the Durchgangwald landslide occurred in the Bølling–Allerød interstadial (14.7–12.9 ka). In the Younger Dryas (12.9–11.7 ka) glaciers overflowed parts of the Durchgangwald landslide deposit followed by the Lenzanger landslide (Preboreal, Early Holocene). North of Kolm-Saigurn, the Bucheben landslide (Early Holocene) and the Lechnerhäusel landslide (Middle Holocene) showed first a rockslide phase followed by a rock avalanche (sturzstrom), which led to the formation of toma in the distal area. All landslides detached from the western flank of the valley, whereas the eastern slopes are predominantly characterized by slow, deep-seated gravitational slope deformation (DSGSD). The most recent significant mass wasting was caused by rockfalls and catastrophic debris flows.

Limnophyes knispelae sp. n. and L. sartorii sp. n., two new crenophilous species from the Swiss Alps (Chironomidae, Orthocladiinae)

Limnophyes knispelae sp. n and L. sartorii sp. n. are diagnosed and described based on material collected in the high Alpine valley of the Rhône river and the cirque of Macun in the Swiss National Park (alt. 1800-2616 m a.s.l.). The first new species is described only as male adult, while the second as male adult and pupal exuviae. Main distinguishing characters found in the male adult of L. knispelae sp. n. L. sartorii sp. n. are: clypeus shield-like shaped; humeral pit typically circular with 3-4 or 9 lanceolate setae; virga strong spine-like; preepisternals vary from 4-6 to 4-8. The pupal exuviae of L. sartorii sp. n. is characterized by having frontal apotome domed; thoracic horn reduced to nose-like tubercle; posterior area of tergites II-VI with 1-7 rows of minute hooks; segment VIII with 5 lateral setae; inner posterior margin of anal lobe straight. A combination of the latter relevant morphological characters has allowed us to consider each of the two new species as a local biogeographic representative of the Swiss Alps. Currently, the genus Limnophyes Eaton, 1875 is represented in Switzerland by 15 species. Consequently, the description of L. knispelae sp. n and L. sartorii sp. n. increases the total number in the genus to 17 known valid species from this country. Discussions and a differential diagnosis on the two new species are given, in which some morphological affinities and distinguishing characters with other related congeners are detailed and highlighted. Comments on the ecology and geographical distribution of the new species are also provided.

Reinventing the attractiveness of borders in the French Alps: the challenge of access to lodging in a tourist context

This article seeks to understand how relatively isolated French Alpine valleys are influenced by economic (tourism, real estate market, etc.) and demographic (in settling inhabitants, gentrification, etc.) dynamics which can act in contradictory ways, both as development factors and as obstacles to the sustainability of the settlement of pleasure migrants. The objective of this article is to examine precisely the difficulties of access to housing and the different characteristics of the phenomenon of rural gentrification in the context of the high alpine valleys (profiles of new arrivals, co-presence of users). It is a question of understanding the complexity of the phenomenon through the analysis of the real estate market and of identifying the difficulties in terms of socio-spatial inequalities specific to these territories. This article proposes to analyze the impact of tourism activity according to the settlement of inhabitants and through the prism of the long-term attractiveness of the regions.

One and a half century of avalanche risk to settlements in the upper Maurienne valley inferred from land cover and socio-environmental changes.

Changes in mountain landscape can affect avalanche activity, causing changes in risk, potentially enhanced by a transition of the socio-environmental system and its underlying dynamics. Thus, integrative approaches combining biophysical and social sciences are required to assess changes in risk in all its dimensions. This study proposes a holistic methodology combining land cover change detection using advanced image processing techniques, geohistorical investigations and qualitative modelling of risk changes in order to infer the evolution of avalanche risk and its drivers in the upper Maurienne (French Alps) from 1860 to 2017. Results show that a continuous increase of forested areas associated with the retraction of agro-pastoral zones followed a period of land abandonment and depopulation. However, reforestation within avalanche paths remains largely incomplete and mostly absent in the majority of release areas, making a decrease in avalanche occurrence and propagation unlikely. This, combined with marked urban sprawl partially concentrated in avalanche prone areas, locally increased the exposure of residential settlements to avalanches. Hence, even if new defense structures have been set up, our analysis indicates that avalanche risk in the upper Maurienne increased through the study period. Even if local specificity related to physical dissimilarities and/or distinguished socio-economic trends always exist, our results may be valid for many high alpine valleys. Our approach is also transferable to other natural hazards, notably in wider mountain environments, as a contribution to the elaboration of effective adaptation strategies in a context of increasing risks related to combined climate change and socio-economic transitions.

Danger along the high road: report from the 2017 field season of the Vayots Dzor Fortress Landscapes Project (VDFLP), Armenia

The Vayots Dzor Fortress Lansdscapes Project investigates the rise and fall of fortress culture in southern Armenia, focusing on the Late Bronze/Early Iron and medieval periods. The paper summarises the findings of the inaugural field season in 2017. The team performed extensive and intensive survey in a high alpine valley that was a key transportation corridor between Lake Sevan in the north and Nakhichevan and northwest Iran to the south. The project employed digital mapping, drone photogrammetry and digital storytelling in support of digital humanities approaches. Important findings include the documentation of Late Bronze/Early Iron cyclopean fortress architecture situated along roads as well as evidence for Urartian control of the valley. Furthermore, medieval structures and monuments are prominent features in the archaeological record of the valley.

Multitemporal Accuracy and Precision Assessment of Unmanned Aerial System Photogrammetry for Slope-Scale Snow Depth Maps in Alpine Terrain

Reliable and timely information on the spatio-temporal distribution of snow in alpine terrain plays an important role for a wide range of applications. Unmanned aerial system (UAS) photogrammetry is increasingly applied to cost-efficiently map the snow depth at very high resolution with flexible applicability. However, crucial questions regarding quality and repeatability of this technique are still under discussion. Here we present a multitemporal accuracy and precision assessment of UAS photogrammetry for snow depth mapping on the slope-scale. We mapped a 0.12 km2 large snow-covered study site, located in a high-alpine valley in Western Austria. 12 UAS flights were performed to acquire imagery at 0.05 m ground sampling distance in visible (VIS) and near-infrared (NIR) wavelengths with a modified commercial, off-the-shelf sensor mounted on a custom-built fixed-wing UAS. The imagery was processed with structure-from-motion photogrammetry software to generate orthophotos, digital surface models (DSMs) and snow depth maps (SDMs). Accuracy of DSMs and SDMs were assessed with terrestrial laser scanning and manual snow depth probing, respectively. The results show that under good illumination conditions (study site in full sunlight), the DSMs and SDMs were acquired with an accuracy of ≤ 0.25 and ≤ 0.29 m (both at 1σ), respectively. In case of poorly illuminated snow surfaces (study site shadowed), the NIR imagery provided higher accuracy (0.19 m; 0.23 m) than VIS imagery (0.49 m; 0.37 m). The precision of the UASSDMs was 0.04 m for a small, stable area and below 0.33 m for the whole study site (both at 1σ).

Exposure dating of a pronounced glacier advance at the onset of the late-Holocene in the central Tyrolean Alps

A two-phased moraine system in the high Alpine valley of Lisenser Längental in the Stubai Alps of western Austria is located in an intermediate morphostratigraphic position constrained by ‘Egesen Stadial’ (Younger Dryas) moraines down valley and ‘Little Ice Age’ (‘LIA’) positions (modern times) up valley. The equilibrium line altitude (ELA) was about 50 m lower than during the ‘LIA’ when applying an accumulation area ratio of 0.67. Exposure dating of boulders with 10Be yields a mean age of 3750 ± 330 years for the more extensive outer moraine system and a single age of 3140 ± 280 years for the inner one. The ages correspond well to the ‘Loebben oscillation’, a sequence of multi-decadal to multi-centennial cooling phases at the onset of the late-Holocene, also recognized in other Alpine records. The climatic downturn was severe enough to cause small to medium-sized Alpine glaciers in the central Alps to advance significantly beyond their ‘LIA’ extent, but too short to trigger a similar reaction with large glaciers.

Spatial and temporal variability of bacterial communities in high alpine water spring sediments

Water springs are complex, fragile and taxa-rich environments, especially in highly dynamic ecosystems such as glacier forefields experiencing glacier retreat. Bacterial communities are important actors in alpine water body metabolism, and have shown both high seasonal and spatial variations. Seven springs from a high alpine valley (Matsch Valley, South Tyrol, Italy) were examined via a multidisciplinary approach using both hydrochemical and microbiological techniques. Amplified ribosomal intergenic spacer analysis (ARISA) and electric conductivity (EC) measurements, as well as elemental composition and water stable isotopic analyses, were performed. Our target was to elucidate whether and how bacterial community structure is influenced by water chemistry, and to determine the origin and extent of variation in space and time. There existed variations in both space and time for all variables measured. Diversity values more markedly differed at the beginning of summer and then at the end; the extent of variation in space was prevalent over the time scale. Bacterial community structural variation responded to hydrochemical parameter changes; moreover, the stability of the hydrochemical parameters played an important role in shaping distinctive bacterial communities.

Sediment connectivity in the high-alpine valley of Val Müschauns, Swiss National Park — linking geomorphic field mapping with geomorphometric modelling

The efficiency of sediment routing through mountain sediment cascades is controlled by the connectivity of hillslopes to the main river system. A lack of connectivity may cause long-term sediment storage and exclude large fractions of a basin from the sediment routing for several thousand years. Here, we studied sediment dynamics in a small, formerly glaciated valley in the Swiss Alps. To characterise the sediment connectivity to the stream, we calculated a morphometric index using a GIS algorithm. The modelling results were tested against a field based geomorphic mapping of sediment storages, which were evaluated with respect to their state of (de)coupling. In accordance to the field diagnostics, the modelling results indicate very well that the present-day sediment flux is conditioned by the glacial valley morphometry inherited through Pleistocene glaciation. Especially in the upper hanging valleys, the connectivity index is reduced noticeably due to the glacial cirque morphology. Based on the field mapping, 30% of the hillslope sediment cascades are interrupted and 20% of the storage boundaries are currently affected by a lack of material transfer. As a consequence, ~29% of the basin surface is currently disconnected from the main river. Nevertheless, the GIS algorithm overestimates the connectivity within the basin, because it fails to calculate decoupling between neighbouring pixels in digital terrain models (DTMs). Around 35% of the basin surface, which has been mapped in the field as being decoupled, is related to relative high connectivity. Our study highlights the potential of morphometric GIS modelling for studying sediment connectivity, but additionally emphasises the indispensability of geomorphic field mapping for a holistic understanding of mountain cascading systems.

Early East Antarctic Ice Sheet growth recorded in the landscape of the Gamburtsev Subglacial Mountains

The Gamburtsev Subglacial Mountains are regarded as a key nucleation site for the Antarctic Ice Sheet and they retain a unique long-term record of pre-glacial and early glacial landscape evolution. Here, we use a range of morphometric analyses to constrain the nature of early glaciation and subsequent ice sheet evolution in the interior of East Antarctica, using a new digital elevation model of the Gamburtsev Subglacial Mountains, derived from an extensive airborne radar survey. We find that an inherited fluvial landscape confirms the existence of the Gamburtsev Subglacial Mountains prior to the onset of glaciation at the Eocene–Oligocene climate boundary (ca. 34Ma). Features characteristic of glaciation, at a range of scales, are evident across the mountains. High elevation alpine valley heads, akin to cirques, identified throughout the mountains, are interpreted as evidence for early phases of glaciation in East Antarctica. The equilibrium line altitudes associated with these features, combined with information from fossil plant assemblages, suggest that they formed at, or prior to, 34Ma. It cannot be ruled out that they may have been eroded by ephemeral ice between the Late Cretaceous and the Eocene (100–34Ma). Hanging valleys, overdeepenings, truncated spurs and steep-sided, linear valley networks are indicative of a more widespread alpine glaciation in this region. These features represent ice growth at, or before, 33.7Ma and provide a minimum estimate for the scale of the East Antarctic Ice Sheet between ca. 34 and 14Ma, when dynamic fluctuations in ice extent are recorded at the coast of Antarctica. The implications are that the early East Antarctic Ice Sheet grew rapidly and developed a cold-based core that preserved the alpine landscape. The patterns of landscape evolution identified provide the earliest evidence for the development of the East Antarctic Ice Sheet and can be used to test coupled ice–climate evolution models.

Quaternary slope processes and morphologies in the upper Sehonghong Valley, eastern Lesotho

Several high south-facing slopes in the southern Drakensberg were glaciated during the Late Quaternary, yet little is known about the slope geomorphic history on equally high slopes that appear not to have been glaciated. To this end, we examine evidence for Late Quaternary slope dynamics in a high alpine valley of eastern Lesotho, with particular attention given to palaeo-environmental signatures offered by deep colluvial mantles along the flanks of the Sehonghong River and pronival ramparts along the upper southerly-facing slopes of the adjoining Thabana-Ntlenyana. Sedimentary exposures were mapped and sampled for clast fabric, clast shape, organic matter content, granulometry and 14C age determination. Similarly, a pronival rampart was mapped and clast size, shape and fabric determined for various micro-topographic settings. A palaeosol beneath the rampart was also Radiocarbon dated. Findings suggest that the deep and extensive debris mantles on lower south-facing slopes are a product of prolonged colluviation, whilst the more stratified sequences on north-facing slopes indicate greater slope geomorphic-process variability over time. Radiocarbon ages suggest sediment accumulation along the north-facing exposure from at least ∼43 ka. It is proposed that snowcreep and snowpush on high (>3400 m a.s.l.) southeast-facing slopes during a relatively cold, yet moist period at ∼AD 300–1000 initiated boulder movement to form the pronival ramparts.

Quantifying sediment storage in a high alpine valley (Turtmanntal, Switzerland)

AbstractThe determination of sediment storage is a critical parameter in sediment budget analyses. But, in many sediment budget studies the quantification of magnitude and time‐scale of sediment storage is still the weakest part and often relies on crude estimations only, especially in large drainage basins (>100 km2). We present a new approach to storage quantification in a meso‐scale alpine catchment of the Swiss Alps (Turtmann Valley, 110 km2).The quantification of depositional volumes was performed by combining geophysical surveys and geographic information system (GIS) modelling techniques. Mean thickness values of each landform type calculated from these data was used to estimate the sediment volume in the hanging valleys and the trough slopes. Sediment volume of the remaining subsystems was determined by modelling an assumed parabolic bedrock surface using digital elevation model (DEM) data.A total sediment volume of 781·3×106–1005·7×106 m3 is deposited in the Turtmann Valley. Over 60% of this volume is stored in the 13 hanging valleys. Moraine landforms contain over 60% of the deposits in the hanging valleys followed by sediment stored on slopes (20%) and rock glaciers (15%).For the first time, a detailed quantification of different storage types was achieved in a catchment of this size. Sediment volumes have been used to calculate mean denudation rates for the different processes ranging from 0·1 to 2·6 mm/a based on a time span of 10 ka.As the quantification approach includes a number of assumptions and various sources of error the values given represent the order of magnitude of sediment storage that has to be expected in a catchment of this size. Copyright © 2009 John Wiley & Sons, Ltd.

Characteristics of wet-snow avalanche activity: 20 years of observations from a high alpine valley (Dischma, Switzerland)

The occurrence of wet-snow avalanches is, in general, poorly understood. For 20 years (winters of 1975–1976 to 1994–1995), the avalanche activity has been observed in the Dischma valley near Davos (Eastern Swiss Alps). The study area comprises a large starting zone of north-easterly aspect (2,300 m a.s.l.) with several avalanche paths. We have analyzed the occurrence data in combination with meteorological and snowpack data collected at an elevation of 2,090 m a.s.l. During the 20-year observation period, almost 800 wet-snow avalanches were observed, about 4.5 times more loose snow avalanches than slab avalanches. Considering both types of avalanches jointly, snow depth, precipitation and air temperature showed the highest correlation with avalanche activity. Most loose snow avalanches occurred when air temperature was high and/or after a precipitation period. Slab avalanches occurrence was primarily related to warm air temperatures and snowpack properties such as the isothermal state and the existence of capillary barriers. Radiation did not show up as a significant variable. The results suggest that in a transitional snow climate wet-snow avalanches are, as dry snow avalanches, often related to precipitation events, and that wet slab instability strongly depends on snowpack properties in relation to warming of the snowpack and melt water production.

Comparing geophysical methods for talus slope investigations in the Turtmann valley (Swiss Alps)

Three geophysical methods, ground penetrating radar, 2D-resistivity and seismic refraction were applied to two landform complexes in a high-alpine valley in Switzerland to investigate their internal structure. Results of the different methods were analysed separately, before conclusions about sediment thickness and geomorphologic implications were drawn. The results from the three methods were compared to focus on the quality of the methods and their field utility, with respect to portability of equipment, required man-power and measurement time. In this study, ground penetrating radar and seismic refraction proved to be the most suitable with respect to the quality and resolution of the subsurface information and the level of field utility. Sediment thicknesses of 15 m on a rectilinear slope and more than 30 m on a talus cone have been measured; a backweathering rate of approximately 700 mm ka − 1 was established. Furthermore, the radar delivered detailed internal sediment structure as well as interfaces between talus and rock glacier. The combined geophysical investigation produced a detailed image of the subsurface composition of the two landform complexes that enhance the understanding of the paraglacial landform evolution in this hanging valley.

The contribution of condensation to the water cycle under high‐mountain conditions

AbstractLittle is known about the interaction between condensation, precipitation and evaporation as an integral part of the water cycle under high‐mountain conditions. This paper focuses on methods of identification and measurement of condensation under natural conditions in high alpine valleys by example of the Dischma in eastern Switzerland. The role of different vegetation zones in transferring water from and to the atmosphere is investigated above the treeline (1900–2600 m a.s.l.). Field measurements of condensation and evaporation at 10 min intervals show that condensation plays a more significant role in the water cycle than previously assumed. Both diurnal and nocturnal condensation are compared at different altitudes on slope and valley locations during the exceptionally hot and dry mid‐summer of 1998. It is suggested that, in addition to standard hydrological components, water balance modelling in mountain zones should include more precise data on measured condensation. Copyright © 2005 John Wiley & Sons, Ltd.

A new instrumental precipitation dataset for the greater alpine region for the period 1800-2002

The paper describes the development of a dataset of 192 monthly precipitation series covering the greater alpine region (GAR, 4–18°E by 43–49°N). A few of the time series extend back to 1800. A description is provided of the sometimes laborious processes that were involved in this work: from locating the original sources of the data to homogenizing the records and eliminating as many of the outliers as possible. Locating the records required exhaustive searches of archives currently held in yearbooks and other sources of the states, countries and smaller regional authorities that existed at various times during the last 200 years. Homogeneity of each record was assessed by comparison with neighbouring series, although this becomes difficult when the density of stations reduces in the earliest years. An additional 47 series were used, but the density of the sites in Austria and Switzerland was reduced to maintain an even coverage in space across the whole of the GAR. We are confident of the series back to 1840, but the quality of data before this date must be considered poorer. Of all of the issues involved in homogenizing these data, perhaps the most serious problem is associated with the differences in the height above ground of the precipitation gauges, in particular the general lowering of gauge heights in the late 19th century for all countries, with the exception of Italy. The standard gauge height in the early-to-mid 19th century was 15–30 m above the ground, with gauges being generally sited on rooftops. Adjustments to some series of the order of 30–50% are necessary for compatibility with the near-ground location of gauges during much of the 20th century. Adjustments are sometimes larger in the winter, when catching snowfall presents serious problems. Data from mountain-top observatories have not been included in this compilation (because of the problem of measuring snowfall), so the highest gauge sites are at elevations of 1600–1900 m in high alpine valley locations. Two subsequent papers will analyse the dataset. The first will compare the series with other large-scale precipitation datasets for this region, and the second will describe the major modes of temporal variability of precipitation totals in different seasons and determine coherent regions of spatial variability. Copyright © 2005 Royal Meteorological Society

Espaces, usages et dynamiques de la dette dans les hautes vallées dauphinoises (XVIe-XVIIIe siècles)

Le crédit est à la fois bien connu des historiens parce que toujours mentionné et méconnu parce que peu analysé dans la diversité de ses pratiques. L'attention a surtout été portée sur l'analyse des transferts de propriété qu'il a permis, partant sur son rôle d'instrument économique. Pourtant, le crédit ne se réduit pas à ce seul aspect : il est aussi un lien social, culturel et parfois un instrument politique. L'objectif de ce texte est de montrer — à travers l'analyse des pratiques de crédit que l'on observe dans les communautés montagnardes du haut Dauphiné aux XVIIe et XVIIIe siècles— la diversité des espaces géographiques que dessinent les relations de crédit et les différents rôles qu'assume le lien de la dette.

Ranging behaviour of the red fox in the Gran Paradiso National Park (Italy)

Abstract The home-ranges and activities of the fox were studied by radiotelemetry in a high alpine valley of the Gran Paradiso National Park (Aosta, Italy). The patterns of food dispersion and availability, combined with those of human disturbance, are the shaping pressure on the fox's use of its range in a peculiar way. Foxes seem to prefer an intermediate belt between the valley floor and the high pasture as denning and resting areas where they return every day: this pattern seems the optimal strategy to have access to the food resources of both low and high altitude habitats. Success rates of different trapping gears are presented.

On Competition Between Galium Saxatile L. (G. Hercynicum Weig.) and Galium Sylvestre Poll. (G. Asperum Schreb.) On Different Types of Soil

The publication, so long ago as 1865, of Nageli's paper on the conditions of occurrence of species and. varieties within their areas of distribution1 brought into prominence an ecological problem of considerable interest and importance, namely the relation of competition between species, particularly closely related species, to their soil preferences. The striking case of Achillea moschata and A. atrata, particularly their distribution in the Heuthal, a high alpine valley in the Bernina region of the Upper Engadine, at once suggests the investigation of this relation, but definite attempts to elucidate the problem appear to have been lacking. Achillea moschata is a widely distributed species of siliceous soils in the Alps and is reputed calcifuge: A. atrata, on the other hand, is calcicole; and each, on its own soil, is said to suppress the other. But where either of the two is absent altogether from a region the other grows on calcareous and non-calcareous soils alike, though A. atrata is said to colonise non-calcareous soils with less difficulty than that experienced by its congener in colonising calcareous soils. In the Heuthal Nageli found a large block of limestone, barely covered with a thin layer of soil, which had fallen on to an area of non-calcareous schist. On this block a colony of A. moschata had established itself, competition with the other species being excluded. A number of pairs of closely allied species or varieties, both in the Alps and in other parts of Europe, show similar sVrongly contrasted soil preferences, and the relation described by Nageli, each form being bodenstet where both occur and bodenvag where its congener is absent, appears to be common2. In order to elucidate this interesting phenomenon it is evidently first necessary to grow the two species of such a pair in competition on different types of soil and to see exactlv what happens. Of a number of pairs of closelv allied

The Structure of the Davos Valley

In several of the high Alpine passes and valleys there are certain structural features which show that important changes in the process of denudation have taken place, and that in many cases there has been an alteration or complete reversal of the drainage-system. Among a considerable number of instances, that of the Upper Engadine or source of the Inn is perhaps the most familiar. Prof. Heim, Prof. Bonney, and others have called attention to this area as showing the way in which the gorges of the southern side of the Alps are cut back with far greater steepness than the river-valleys of the northern slopes. While Prof. Bonney regards the difference as due to the greater rainfall and more rapid current on the southern side, and the consequently greater erosive power of the torrents, Dr. Preller believes that it is not possible to account for the present condition of the district without presupposing a subsidence on the south. Whichever view may be held, however, there is no doubt as to the facts. It can hardly be disputed that the Inn once took its rise beyond Maloja, and that the glaciers on the south once contributed to its formation streams now diverted towards the Italian plain. The valley has in fact been decapitated, and its feeding-streams have been diverted into a new and opposite course. The object of the present paper is to call attention to the conditions which exist in the adjacent area of Davos: conditions which are to some extent parallel, but, on the other hand, are distinctly more complicated and less easy of explanation.