Will the Pyrenees suffer less rainfall-triggered landslides in the future? Results of regional-scale stability modelling in the Val d’Aran focussing on land cover and rainfall predictions. 

2021 ◽  
Author(s):  
Marcel Hürlimann ◽  
Zizheng Guo ◽  
Càrol Puig-Polo ◽  
Vicente Medina
Keyword(s):  
Climate Changes ◽  
Environmental Changes ◽  
Daily Rainfall ◽  
Stability Conditions ◽  
High Mountain ◽  
Mountain Areas ◽  
Lulc Changes ◽  
Overall Stability ◽  
The Future ◽  
Root Strength

<p>The occurrence of rainfall-induced landslides in high-mountain areas will be affected by future environmental changes. We analysed the influence of climate changes as well as land use and land cover (LULC) changes on shallow slope failures in the Val d’Aran region (Central Pyrenees) applying the simplified physically-based susceptibility model FSLAM. In this study, the event rainfall as well as the root strength were defined as the two input parameters that will be affected by the future changes.</p><p>On one side, the climate changes were analysed by the rainfall projections that are defined in the 26 regional climate models available at the moment in the EURO-CORDEX database using RCP 8.5 scenarios. Future precipitation return periods up to 2100 were calculated by a simplified peaks-over-threshold method based on storm events frequency analysis. Finally, daily rainfall scenarios for the entire study were estimated by weighting current rainfall extremes using a multiplier factor. On the other side, the LULC changes were calculated by the IDRISI TerrSet software suite. All the predictions were performed for three time periods (near, mid and far future).</p><p>The results of the climate change prediction showed that the daily rainfall will increase between 15 and 27 % assuming a return period of 100 years. In addition, the LULC predictions foresee a strong increase of the forest area, while in particular grassland, but also shrubs, decrease in area. Using the different rainfall and LULC predictions, multiples scenarios were defined and the corresponding susceptibility maps calculated. The stability calculations by the FSLAM model indicate that the overall stability conditions in the study area reduces when only the future rainfall prediction is considered. In contrast, the overall stability largely improves when only considering the LULC predictions (due to the increase of forest area and the corresponding higher root strength). However, the effect of LULC-changes is more important than the influence of rainfall-changes. Therefore, the overall stability conditions will improve in the future.</p><p>Many simplifications were incorporated in this susceptibility assessment and there are many uncertainties. Nonetheless, these results may help future studies to improve our knowledge on the impacts of future environmental changes on landslide occurrence in high-mountain areas.</p>

Impacts of future land cover and climate changes on landslide susceptibility. Results obtained from regional-scale modelling in the Pyrenees.

2020 ◽  
Author(s):  
Marcel Hürlimann ◽  
Vicente Medina ◽  
Zizheng Guo ◽  
Carol Puig-Polo ◽  
Antonio Lloret ◽  
...  
Keyword(s):  
Land Cover ◽  
Landslide Susceptibility ◽  
Climate Changes ◽  
Rainfall Intensity ◽  
Regional Scale ◽  
Stability Conditions ◽  
Lulc Changes ◽  
Mountainous Regions ◽  
Overall Stability ◽  
Physically Based

<p>Future environmental changes will strongly affect the occurrence of rainfall-induced landslides in mountainous regions. In our ongoing study, we focus on the effects of climate changes as well as land use and land cover (LULC) changes on shallow slope failures in the Pyrenees. For this reason, a physically-based susceptibility model was developed, which calculates the landslide susceptibility at regional scale. The model merges two different approaches for the calculation of pore fluid pressure and also includes the option of defining the values of input parameters stochastically.</p><p>The model was validated using landslide inventories from two different study areas located in the Central and Eastern Pyrenees. One is the inventory of historic shallow slides and debris flows in Andorra country. The other one is the inventory of the catastrophic landslide episode in Val d’Aran area in June 2013, which includes 393 landslide initiation points. The susceptibility modelling of these two validation cases produced acceptable results and showed that our physically-based model is producing consistent stability conditions.</p><p>In the next step, the future LULC and climate changes until the end of the 21th century were simulated for Val d’Aran study area. The LULC changes were determined with the IDRISI TerrSet software suite, while the climate changes were obtained from the ensemble of regional climate models using RCP 4.5 and 8.5 scenarios. The results of the susceptibility modelling showed that the impacts of future LULC changes increase the overall stability because of the larger area of forest and shrubs (and consequently higher cohesion due to root strength). In contrast, the impact of future climate changes, which was principally incorporated by higher rainfall intensity, reduced the overall slope stability. However, when we compared the impacts of both future changes, the results showed that the influence of the vegetation expansion is more important than the effect of higher rainfall intensity. Therefore, the overall stability conditions in the study area seem to slightly improve in the future.</p><p>As always in such studies, there are many uncertainties in the input data and additional simulations are necessary to confirm the observed trends. Nonetheless, the outcomes provide helpful information for researchers and practitioners that deal with the impacts of future changes on landslide susceptibility in mountainous regions.</p>

Future Extreme Climates Projection over Huang-Huai-Hai Region of China

2014 ◽  
Vol 955-959 ◽  
pp. 3887-3892 ◽  
Author(s):  
Huang He Gu ◽  
Zhong Bo Yu ◽  
Ji Gan Wang
Keyword(s):  
Climate Changes ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Air Temperature ◽  
Daily Rainfall ◽  
Heavy Rain ◽  
Near Surface ◽  
Temperature And Precipitation ◽  
Huai River ◽  
The Future

This study projects the future extreme climate changes over Huang-Huai-Hai (3H) region in China using a regional climate model (RegCM4). The RegCM4 performs well in “current” climate (1970-1999) simulations by compared with the available surface station data, focusing on near-surface air temperature and precipitation. Future climate changes are evaluated based on experiments driven by European-Hamburg general climate model (ECHAM5) in A1B future scenario (2070-2099). The results show that the annual temperature increase about 3.4 °C-4.2 °C and the annual precipitation increase about 5-15% in most of 3H region at the end of 21st century. The model predicts a generally less frost days, longer growing season, more hot days, no obvious change in heat wave duration index, larger maximum five-day rainfall, more heavy rain days, and larger daily rainfall intensity. The results indicate a higher risk of floods in the future warmer climate. In addition, the consecutive dry days in Huai River Basin will increase, indicating more serve drought and floods conditions in this region.

Exploring the future hydrology of a Canadian Rockies glacierized catchment and its sensitivity to meteorological forcings

2021 ◽  
Author(s):  
Caroline Aubry-Wake ◽  
John W. Pomeroy
Keyword(s):  
Hydrological Model ◽  
Comprehensive Evaluation ◽  
Subsurface Water ◽  
High Mountain ◽  
Blowing Snow ◽  
Mountain Areas ◽  
Canadian Rockies ◽  
Process Representation ◽  
The Future ◽  
Physically Based

<p>Glacierized mountain areas are witnessing strong changes in their streamflow generation processes, influencing their capacity to provide crucial water resources to downstream environments. Shifting precipitation patterns, a warming climate, changing snow dynamics and retreating glaciers are occurring simultaneously, driven by complex physical feedbacks. To predict and diagnose future hydrological behaviour in these glacierized catchments, a semi-distributed, physically-based hydrological model including both on and off-glacier process representation was applied to Peyto basin, a 21 km2 glacierized alpine catchment in the Canadian Rockies. The model was forced with bias-corrected outputs from a dynamically downscaled, 4-km resolution Weather and Research Forecasting (WRF) simulation, for the 2000-2015 and 2085-2100 period.  The future WRF runs had boundary conditions perturbed using RCP8.5 late century climate.  The simulations show by the end-of-century, the catchment shifts from a glacial to a nival regime. The increase in precipitation nearly compensates for the decreased ice melt associated with glacier retreat, with a decrease in annual streamflow of only 7%. Peak flow shifts from July to June and August streamflow is reduced by 68%. Changes in blowing snow transport and sublimation, avalanching, evaporation and subsurface water storage also contribute to the strong hydrological shift in the Peyto catchment. A sensitivity analysis to uncertainty in forcing meteorology reveals that streamflow volume is more sensitive to variations in precipitation whereas streamflow timing and variability are more sensitive to variations in temperature. The combination of the temperature and precipitation variations caused substantial changes both in the future snowpack and in the streamflow pattern. By including high-resolution atmospheric modelling and unprecedented both on and off-glacier process-representation in a physically-based hydrological model, the results provide a particularly comprehensive evaluation of the hydrological changes occurring in high-mountain environments in response to climate change.</p>

scholarly journals The Diatomic Diversity of Two Mediterranean High-Elevation Lakes in the Sibillini Mountains National Park (Central Italy)

Environments ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 79
Author(s):  
Rosalba Padula ◽  
Antonella Carosi ◽  
Alessandro Rossetti ◽  
Massimo Lorenzoni
Keyword(s):  
Sustainable Management ◽  
National Park ◽  
Climate Changes ◽  
Environmental Changes ◽  
Central Italy ◽  
High Elevation ◽  
High Mountain ◽  
Spatial And Temporal Heterogeneity ◽  
Management Plans ◽  
Changes Over Time

Temporary high-elevation lakes represent vulnerable and unstable environments strongly threatened by tourism, hydrogeological transformations and climate changes. In-depth scientific knowledge on these peculiar habitats is needed, on which to base integrated and sustainable management plans. Freshwater diatoms, thanks to their high diversity and their particular sensitivity to the water chemistry, can be considered powerful ecological indicators, as they are able to reflect environmental changes over time. The aim of the present study was to analyze the diatomic diversity of the Pilato and Palazzo Borghese lakes, two small temporary high-mountain basins, falling in a protected area within the Apennine mountains chain (central Italy). Diatoms data were collected, at the same time as 12 physicochemical parameters, through six microhabitat samplings, from 17 June to 30 August 2019. In both lakes, a total of 111 diatomic species and varieties were identified. The most species-rich genera were Gomphonema, Navicula, and Nitzschia. The Pilato Lake showed a diatomic community dominated by few species, favored by more stable and predictable environmental conditions than the Palazzo Borghese Lake, which hosted a more diversified community, guaranteed by greater spatial and temporal heterogeneity. Both lakes were characterized by the presence of diatomic species typical of good quality waters. The occurrence of numerous aerial species reflected adaptation strategies adopted to colonize environments subjected to extended drought periods. Endangered diatomic species of particular conservational interest were recorded, confirming the need to preserve their habitats.

GIS and geomatics for hydrogeodiversity assessment of glaciated mountains: examples from the Western Alps (Italy) and the Coast Mountains (Canada)

2020 ◽  
Author(s):  
Luigi Perotti ◽  
Manuela Lasagna ◽  
Gilda Carraro ◽  
Cristina Viani ◽  
Federico Tognetto ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Environmental Changes ◽  
Western Alps ◽  
High Mountain ◽  
Mountain Areas ◽  
Coast Mountains ◽  
Climate Change Effects ◽  
Monitoring Tools ◽  
Detailed Interpretation ◽  
Temporal Dimensions

<p>This paper aims at the systematization of knowledge related to geodiversity assessment for water resources and its evaluation within high mountain areas. In this environmental context, geological features, landforms and geomorphological processes, soils and water too are particularly sensitive to climatic and environmental changes, thus giving geodiversity a particularly dynamic character.</p><p>A multidimensional (regional, local; present, past) approach was developed for analyzing components of geomorphological and hydrogeological systems, both at superficial and underground level, in order to establish a conceptual model and a specific procedure for the evaluation of geodiversity.</p><p>Spatial and temporal dimensions of glaciated mountain landscapes of the Italian Western Alps (Monte Rosa, Maggiore Lake, Sesia Val Grande UNESCO Global Geopark) and the Coast Mountains of Canada (Mount Meager, Lillohet Valley, Sea-to-Sky Corridor) were mapped and interpreted by means of: 1) detailed interpretation of DEM-derived data, 2) proper selection of Geomatics survey and monitoring tools and 3) targeted application of GIS analytical methods. The selection and processing operations of the elements considered for this evaluation led to the identification of areas characterized by greater values of hydrogeodiversity. Here, the link between surface and underground hydrodynamics becomes closer and intense, thus conditioning the local landscape setting and the interactions of its natural and human components.</p><p>The conceptual model and related workflow proved to be useful for both a) enhanced accuracy of models of a diversity of geomorphological and hydrogeological elements and processes of mountain regions and b) improved “targeted” knowledge on hydrogeodiversity and increased awareness on related geoheritage.</p><p>The proposed GIS and Geomatics framework allowed the hydrogeodiversity assessment going well beyond the limit of classical geomorphological and hydrogeological techniques. Difficulty of quantitative analysis over large areas was overcome, and small landscape features and other “hidden” hydrogeological markers could be taken into account. The results of the research strengthened the possibility of strategic management of geological, geomorphological and hydrological heritages within the study areas. In fact, we identified different landscapes and local peculiarities determined by mutual influences between geology and hydrological dynamics and mapped their possible interaction with human activities and infrastructures within areas of enhanced climate change effects.</p>

scholarly journals Responses of Benthic Macroinvertebrate Communities of Two Tropical, High-Mountain Lakes to Climate Change and Deacidification

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 243
Author(s):  
Javier Alcocer ◽  
Luis A. Oseguera ◽  
Diana Ibarra-Morales ◽  
Elva Escobar ◽  
Lucero García-Cid
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Water Temperature ◽  
Water Level ◽  
Environmental Changes ◽  
Mountain Lakes ◽  
High Mountain ◽  
Macroinvertebrate Communities ◽  
High Mountain Lakes ◽  
La Luna

High-mountain lakes are among the most comparable ecosystems globally and recognized sentinels of global change. The present study pursued to identify how the benthic macroinvertebrates (BMI) communities of two tropical, high mountain lakes, El Sol and La Luna, Central Mexico, have been affected by global/regional environmental pressures. We compared the environmental characteristics and the BMI communities between 2000–2001 and 2017–2018. We identified three principal environmental changes (the air and water temperature increased, the lakes’ water level declined, and the pH augmented and became more variable), and four principal ecological changes in the BMI communities [a species richness reduction (7 to 4), a composition change, and a dominant species replacement all of them in Lake El Sol, a species richness increase (2 to 4) in Lake La Luna, and a drastic reduction in density (38% and 90%) and biomass (92%) in both lakes]. The air and water temperature increased 0.5 °C, and lakes water level declined 1.5 m, all suggesting an outcome of climate change. Contrarily to the expected acidification associated with acid precipitation, both lakes deacidified, and the annual pH fluctuation augmented. The causes of the deacidification and the deleterious impacts on the BMI communities remained to be identified.

scholarly journals Debris Flows Occurrence in the Semiarid Central Andes under Climate Change Scenario

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 43
Author(s):  
Stella M. Moreiras ◽  
Sergio A. Sepúlveda ◽  
Mariana Correas-González ◽  
Carolina Lauro ◽  
Iván Vergara ◽  
...  
Keyword(s):  
Climate Change ◽  
Debris Flows ◽  
Environmental Changes ◽  
Urban Expansion ◽  
Central Andes ◽  
Semiarid Region ◽  
Change Scenario ◽  
Permafrost Degradation ◽  
Mountain Areas ◽  
Negative Impacts

This review paper compiles research related to debris flows and hyperconcentrated flows in the central Andes (30°–33° S), updating the knowledge of these phenomena in this semiarid region. Continuous records of these phenomena are lacking through the Andean region; intense precipitations, sudden snowmelt, increased temperatures on high relief mountain areas, and permafrost degradation are related to violent flow discharges. Documented catastrophic consequences related to these geoclimatic events highlight the need to improve their understanding in order to prepare the Andean communities for this latent danger. An amplified impact is expected not only due to environmental changes potentially linked to climate change but also due to rising exposure linked to urban expansion toward more susceptible or unstable areas. This review highlights as well the need for the implementation of preventive measures to reduce the negative impacts and vulnerability of the Andean communities in the global warming context.

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
Keyword(s):  
Sierra Nevada ◽  
Unknown Origin ◽  
Slope Instability ◽  
Water Bodies ◽  
High Mountain ◽  
Mountain Areas ◽  
Glacial Processes ◽  
The Mediterranean ◽  
Water Volumes

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.

scholarly journals Climate change drives mountain butterflies towards the summits

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dennis Rödder ◽  
Thomas Schmitt ◽  
Patrick Gros ◽  
Werner Ulrich ◽  
Jan Christian Habel
Keyword(s):  
Climate Change ◽  
Life History ◽  
Climate Warming ◽  
Environmental Changes ◽  
Range Shifts ◽  
Solar Irradiation ◽  
High Mountain ◽  
Detailed Knowledge ◽  
Annual Range

AbstractClimate change impacts biodiversity and is driving range shifts of species and populations across the globe. To understand the effects of climate warming on biota, long-term observations of the occurrence of species and detailed knowledge on their ecology and life-history is crucial. Mountain species particularly suffer under climate warming and often respond to environmental changes by altitudinal range shifts. We assessed long-term distribution trends of mountain butterflies across the eastern Alps and calculated species’ specific annual range shifts based on field observations and species distribution models, counterbalancing the potential drawbacks of both approaches. We also compiled details on the ecology, behaviour and life-history, and the climate niche of each species assessed. We found that the highest altitudinal maxima were observed recently in the majority of cases, while the lowest altitudes of observations were recorded before 1980. Mobile and generalist species with a broad ecological amplitude tended to move uphill more than specialist and sedentary species. As main drivers we identified climatic conditions and topographic variables, such as insolation and solar irradiation. This study provides important evidence for responses of high mountain taxa to rapid climate change. Our study underlines the advantage of combining historical surveys and museum collection data with cutting-edge analyses.

Future changes in heatwaves over Africa at the convection-permitting scale

2021 ◽  
Author(s):  
Cathryn Birch ◽  
Lawrence Jackson ◽  
Declan Finney ◽  
John Marsham ◽  
Rachel Stratton ◽  
...  
Keyword(s):  
Climate Model ◽  
Daily Rainfall ◽  
Shortwave Radiation ◽  
Daily Maximum ◽  
Future Change ◽  
Driving Mechanisms ◽  
The Future ◽  
Convective Scale ◽  
Climate Model Simulations ◽  
The Impact

<p>Mean temperatures and their extremes have increased over Africa since the latter half of the 20th century and this trend is projected to continue, with very frequent, intense and often deadly heatwaves likely to occur very regularly over much of Africa by 2100. It is crucial that we understand the scale of the future increases in extremes and the driving mechanisms. We diagnose daily maximum wet bulb temperature heatwaves, which allows for both the impact of temperature and humidity, both critical for human health and survivability. During wet bulb heatwaves, humidity and cloud cover increase, which limits the surface shortwave radiation flux but increases longwave warming. It is found from observations and ERA5 reanalysis that approximately 30% of wet bulb heatwaves over Africa are associated with daily rainfall accumulations of more than 1 mm/day on the first day of the heatwave. The first ever pan-African convection-permitting climate model simulations of present-day and RCP8.5 future climate are utilised to illustrate the projected future change in heatwaves, their drivers and their sensitivity to the representation of convection. Compared to ERA5, the convection-permitting model better represents the frequency and magnitude of present-day wet bulb heatwaves than a version of the model with more traditional parameterised convection. The future change in heatwave frequency, duration and magnitude is also larger in the convective-scale simulation, suggesting CMIP-style models may underestimate the future change in wet bulb heat extremes over Africa. The main reason for the larger future change appears to be the ability of the model to produce larger anomalies relative to its climatology in precipitation, cloud and the surface energy balance.</p>

Sign in / Sign up

Export Citation Format

Share Document