scholarly journals Formation Patterns of Mediterranean High-Mountain Water-Bodies in Sierra-Nevada, SE Spain

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 438
Author(s):  
Jose Luis Diaz-Hernandez ◽  
Antonio Jose Herrera-Martinez

At present, there is a lack of detailed understanding on how the factors converging on water variables from mountain areas modify the quantity and quality of their watercourses, which are features determining these areas’ hydrological contribution to downstream regions. In order to remedy this situation to some extent, we studied the water-bodies of the western sector of the Sierra Nevada massif (Spain). Since thaw is a necessary but not sufficient contributor to the formation of these fragile water-bodies, we carried out field visits to identify their number, size and spatial distribution as well as their different modelling processes. The best-defined water-bodies were the result of glacial processes, such as overdeepening and moraine dams. These water-bodies are the highest in the massif (2918 m mean altitude), the largest and the deepest, making up 72% of the total. Another group is formed by hillside instability phenomena, which are very dynamic and are related to a variety of processes. The resulting water-bodies are irregular and located at lower altitudes (2842 m mean altitude), representing 25% of the total. The third group is the smallest (3%), with one subgroup formed by anthropic causes and another formed from unknown origin. It has recently been found that the Mediterranean and Atlantic watersheds of this massif are somewhat paradoxical in behaviour, since, despite its higher xericity, the Mediterranean watershed generally has higher water contents than the Atlantic. The overall cause of these discrepancies between watersheds is not connected to their formation processes. However, we found that the classification of water volumes by the manners of formation of their water-bodies is not coherent with the associated green fringes because of the anomalous behaviour of the water-bodies formed by moraine dams. This discrepancy is largely due to the passive role of the water retained in this type of water-body as it depends on the characteristics of its hollows. The water-bodies of Sierra Nevada close to the peak line (2918 m mean altitude) are therefore highly dependent on the glacial processes that created the hollows in which they are located. Slope instability created water-bodies mainly located at lower altitudes (2842 m mean altitude), representing tectonic weak zones or accumulation of debris, which are influenced by intense slope dynamics. These water-bodies are therefore more fragile, and their existence is probably more short-lived than that of bodies created under glacial conditions.

2020 ◽  
Author(s):  
Andrea Fischer

<p>Today, photos play an important role in geoscience and public discussion. When photographical techniques developed during the second half of the 19th century, it took several decades uuntil high mountain areas and specific features could be captured with this technique, as a follow upt o traditional paintings and drawings. In European geography, Friedrich Simony developed the idea of tackling geomorphological processes by time lapse photography. Contemporary literature shows that his technique of combining photography with empirical data and theories was convincing, and that he established a new style of scientific discussion. Still, the comparison of historical with contemporary photography offers scientific insights and information which is not covered by any other type of empirical evidence as measurements, maps or descriptions. For example not only extent, but also firn and debris cover of glaciers, information on type and extent of vegetation,  the width and style of roads, details of infrastructure and cultural practices can be tackled from early photographs.  Several archives do allow not only acess to photographic documents, but also to metadata. Interdisciplinary effort has to be taken to further analyse this wealth of information.</p>


1989 ◽  
Vol 13 ◽  
pp. 185-188 ◽  
Author(s):  
K.I. MacDonald

Slope instability and occasional devastating landslides are well-known hazards in high mountain areas. This paper describes and discusses an example of extensive and recurring damage associated with agricultural settlements around the lower reaches of the rapidly flowing Bualtar and Barpu Glaciers in northern Pakistan. These landslides occur over a zone about 20 km long in response to erosive processes at the ice-slope interface, and slowly descend 150–300 m from the edges of cultivation to the glacier margins. Damage is evident in the loss and/or abandonment of approximately 10 km2 of land, and in the destruction of dwellings and irrigation channels. The daily routine of local villagers is affected because alterations of both the slope and the ice surface destroy frequently used transport routes. Although the landslides have a history decades long, the landslide problem has more recently assumed heightened significance in relation to rapidly occurring economic and social change such as the introduction of wage labour and seasonal outmigration.


2008 ◽  
Author(s):  
J. M. Marques ◽  
P. M. Carreira ◽  
J. Espinha Marques ◽  
H. I. Chaminé ◽  
P. E. Fonseca ◽  
...  

2020 ◽  
Vol 163 (2) ◽  
pp. 953-972
Author(s):  
Graham McDowell ◽  
Leila Harris ◽  
Michele Koppes ◽  
Martin F. Price ◽  
Kai M.A. Chan ◽  
...  

AbstractAdaptation needs in high mountain communities are increasingly well documented, yet most efforts to address these needs continue to befall mountain people who have contributed little to the problem of climate change. This situation represents a contravention of accepted norms of climate justice and calls attention to the need for better understanding of prospects for externally resourced adaptation initiatives in high mountain areas. In response, this paper examines the architecture of formal adaptation support mechanisms organized through the United Nations Framework Convention on Climate Change (UNFCCC) and how such mechanisms might help to meet adaptation needs in high mountain communities. It outlines key global adaptation initiatives organized through the UNFCCC, clarifies idealized linkages between these global adaptation initiatives and meeting local adaptation needs, and evaluates actual progress in connecting such support with discrete adaptation needs in the upper Manaslu region of Nepal. The paper then critically examines observed shortcomings in matching adaptation support organized through the UNFCCC with local adaptation needs, including complications stemming from the bureaucratic nature of formal adaptation support mechanisms, the intervening role of the state in delivering aid, and the ways in which these complexities intersect with the specific socio-cultural contexts of mountain communities. It concludes by highlighting several prospects for increasing the quantity and quality of adaptation support to mountain communities. These opportunities are considered alongside several salient concerns about formal adaptation support mechanisms in an effort to provide a well-rounded assessment of the prospects for planned adaptations in high mountain communities.


1989 ◽  
Vol 13 ◽  
pp. 185-188
Author(s):  
K.I. MacDonald

Slope instability and occasional devastating landslides are well-known hazards in high mountain areas. This paper describes and discusses an example of extensive and recurring damage associated with agricultural settlements around the lower reaches of the rapidly flowing Bualtar and Barpu Glaciers in northern Pakistan. These landslides occur over a zone about 20 km long in response to erosive processes at the ice-slope interface, and slowly descend 150–300 m from the edges of cultivation to the glacier margins. Damage is evident in the loss and/or abandonment of approximately 10 km2 of land, and in the destruction of dwellings and irrigation channels. The daily routine of local villagers is affected because alterations of both the slope and the ice surface destroy frequently used transport routes. Although the landslides have a history decades long, the landslide problem has more recently assumed heightened significance in relation to rapidly occurring economic and social change such as the introduction of wage labour and seasonal outmigration.


Hydrology ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 59
Author(s):  
Jose Luis Diaz-Hernandez ◽  
Antonio Jose Herrera-Martinez

Each lake complex must be understood before attempting any regional synthesis leading us to view these water-bodies as indicators of regional climate change. Therefore, in order to improve knowledge of these Mediterranean biotopes, we examined the dependence of the fringes of hygrophilous communities surrounding the water-bodies (green fringes) on their hydrological and geomorphological features. The climate of the western sector of this massif is cryo–oromediterranean, where thawing produces 53 hm3 of run-off and 11 hm3 of sub-surface flow. Part of this water is stored in 123 water-bodies located from 2480 to 3200 m a.s.l., 72 of which (58%) are located on the south-facing Mediterranean watershed. The total surface of the water sheet is approximately 170,000 m2, and volume is approximately 215,000 m3, of which 140,000 m3 (65%) are stored in the south-facing water-bodies. Green fringes surrounding 84 water-bodies have a total surface area of approximately 186,000 m2. Surprisingly, the more xeric Mediterranean watershed holds 58 such fringes (149,000 m2, 80%) while 26 are found on the Atlantic watershed (38,000 m2, 20%). Green fringes are mainly associated with small water-bodies (<5000 m3), which occupy 148,000 m2 on the Mediterranean watershed, while on the Atlantic side, green fringes occupy 31,000 m2. Sierra Nevada also has 46 times higher water-efficiency in the smaller water-bodies than in the large ones; 16.4 and 335.8 times higher on the Atlantic and Mediterranean watersheds, respectively. The differences in gradient of the massif hillsides must largely explain this uneven behaviour.


2010 ◽  
Vol 65 (2) ◽  
pp. 146-156 ◽  
Author(s):  
C. Huggel ◽  
L. Fischer ◽  
D. Schneider ◽  
W. Haeberli

Abstract. High-mountain areas with glacier and permafrost occurrence are temperature sensitive environments. Climatic changes are, thus, likely to have an effect on slope stability. Several recent events have shown that rock and ice avalanches and related hazards can have severe consequences. For hazard analysis, the processes of slope failure and flow dynamics should therefore be better understood. In this article, recent advances in this field are presented, including high-resolution topographic monitoring of a large Alpine high-mountain flank (Monte Rosa) over the past 50 years and laboratory experiments with rotating drums and numerical modelling. This recent research has revealed important insight into the causes and dynamics of slope instabilities and contributes towards a better understanding of the influence of ice on avalanche dynamics and runout. It is emphasized that high-mountain slope failures need to be viewed from an interdisciplinary perspective, taking a number of process interactions into account.


2022 ◽  
Vol 10 (1) ◽  
pp. 23-42
Author(s):  
Yan Zhong ◽  
Qiao Liu ◽  
Matthew Westoby ◽  
Yong Nie ◽  
Francesca Pellicciotti ◽  
...  

Abstract. Topographic development via paraglacial slope failure (PSF) represents a complex interplay between geological structure, climate, and glacial denudation. Southeastern Tibet has experienced amongst the highest rates of ice mass loss in High Mountain Asia in recent decades, but few studies have focused on the implications of this mass loss on the stability of paraglacial slopes. We used repeat satellite- and unpiloted aerial vehicle (UAV)-derived imagery between 1990 and 2020 as the basis for mapping PSFs from slopes adjacent to Hailuogou Glacier (HLG), a 5 km long monsoon temperate valley glacier in the Mt. Gongga region. We observed recent lowering of the glacier tongue surface at rates of up to 0.88 m a−1 in the period 2000 to 2016, whilst overall paraglacial bare ground area (PBGA) on glacier-adjacent slopes increased from 0.31 ± 0.27 km2 in 1990 to 1.38 ± 0.06 km2 in 2020. Decadal PBGA expansion rates were ∼ 0.01 km2 a−1, 0.02 km2 a−1, and 0.08 km2 in the periods 1990–2000, 2000–2011, and 2011–2020 respectively, indicating an increasing rate of expansion of PBGA. Three types of PSFs, including rockfalls, sediment-mantled slope slides, and headward gully erosion, were mapped, with a total area of 0.75 ± 0.03 km2 in 2020. South-facing valley slopes (true left of the glacier) exhibited more destabilization (56 % of the total PSF area) than north-facing (true right) valley slopes (44 % of the total PSF area). Deformation of sediment-mantled moraine slopes (mean 1.65–2.63 ± 0.04 cm d−1) and an increase in erosion activity in ice-marginal tributary valleys caused by a drop in local base level (gully headward erosion rates are 0.76–3.39 cm d−1) have occurred in tandem with recent glacier downwasting. We also observe deformation of glacier ice, possibly driven by destabilization of lateral moraine, as has been reported in other deglaciating mountain glacier catchments. The formation, evolution, and future trajectory of PSFs at HLG (as well as other monsoon-dominated deglaciating mountain areas) are related to glacial history, including recent rapid downwasting leading to the exposure of steep, unstable bedrock and moraine slopes, and climatic conditions that promote slope instability, such as very high seasonal precipitation and seasonal temperature fluctuations that are conducive to freeze–thaw and ice segregation processes.


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