What is the contribution of snow and glacier to discharge in Swiss alpine headwater catchments under climate change?

2020 ◽  
Author(s):  
Daphné Freudiger ◽  
Irene Kohn ◽  
Kerstin Stahl ◽  
Markus Weiler ◽  
Jan Seibert
Keyword(s):  
Climate Change ◽  
Hydrological Processes ◽  
Snow Melt ◽  
Headwater Catchments ◽  
Glacier Melt ◽  
Current Climate ◽  
Emissions Scenarios ◽  
Rcp 8.5 ◽  
The Alps ◽  
Total Discharge

<p><span>Switzerland is often referred to as Europe’s Water Tower. During the melt season, water stored in the Alps as snow and ice feeds large European rivers such as the Rivers Rhine and Rhone. Under climate change conditions, snow and glacier melt contributions to discharge are expected to change dramatically. These changes might be very important during dry periods, when snow and glacier melt are the main sources of water. Assessing water availability in the future is essential for sustainable management of our water resources. Understanding how much melt water contributes to the discharge at different locations along the rivers is therefore necessary. </span></p><p><span>In this study, we used a customized version of the bucket-type hydrological model HBV-light, specially developed to assess the daily contribution of snow and glacier melt to discharge in a transient way. We assess the discharge components for 195 glacierized headwater catchments covering the entire Swiss Alps from 1973 to 2099. Hydrological processes in the Alps are spatially and temporally highly variable. Snow and glacier melt modelling are also challenged by data scarcity. Heterogeneously distributed meteorological measurement stations in high elevated and remote regions further complicate the representativity of the data. We show the advantages and challenges of using datasets from various sources as meteorological input data and for model calibration and validation of discharge, snow and glacier cover. In a second step, we applied a regionalization approach to defining model parameters for the ungauged catchments. A multi-criteria calibration was used to ensure that all hydrological processes are correctly represented within the model. </span></p><p><span>For future climate projections, we used the newly generated precipitation and temperature gridded products from MeteoSwiss for 45 climate models and for three emissions scenarios (RCP 2.6, RCP 4.5 and RCP 8.5). The results show that glacier peak water is already reached by most of the catchments and will be reached by all catchments during the first half of the Century for all three emissions scenarios. Under RCP 8.5, total glacier contribution summarized over all headwater catchments is 8% of total discharge under current climate and less than 2% at the end of the century. Snow melt will still be an important contribution to discharge during the first half of the century. In the second half of the century, however, snow melt contribution will significantly decrease from 34% (current climate) to 25% +/- 10% (2070-2099) of the total discharge. In contrary, rainfall contribution will increase from 58% to 72% +/- 15% of total discharge. Overall, the total annual discharge is expected to decrease slightly. The intensity of these changes in discharge contributions depends on the catchment elevation and large regional differences can be observed. The effects are much smaller under emission scenario RCP 2.6. </span></p>

Glaciohydrology of the Himalaya-Karakoram

Science ◽  
2021 ◽  
pp. eabf3668
Author(s):  
Mohd. Farooq Azam ◽  
Jeffrey S. Kargel ◽  
Joseph M. Shea ◽  
Santosh Nepal ◽  
Umesh K. Haritashya ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Current Status ◽  
Snow Melt ◽  
Resources Management ◽  
Critical Knowledge ◽  
Glacier Melt ◽  
Sustainable Water Resources Management ◽  
The Himalaya ◽  
Sustainable Water Resources

Understanding the response of Himalayan-Karakoram (HK) rivers to climate change is crucial for ~1 billion people who partly depend on these water resources. Policymakers tasked with the sustainable water resources management for agriculture, hydropower, drinking, sanitation, and hazards require an assessment of rivers’ current status and potential future changes. This review demonstrates that glacier and snow melt are important components of HK rivers, with greater hydrological importance for the Indus than Ganges and Brahmaputra basins. Total river runoff, glacier melt, and seasonality of flow are projected to increase until the 2050s, with some exceptions and large uncertainties. Critical knowledge gaps severely affect modeled contributions of different runoff components, future runoff volumes and seasonality. Therefore, comprehensive field- and remote sensing-based methods and models are needed.

Response of Hydrological Process to Climate Change of Basins with Different Glacier Ratio in the Tibet Plateau

2020 ◽  
Author(s):  
Li Wang ◽  
Fan Zhang
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Negative Impact ◽  
Positive Impact ◽  
River Basins ◽  
Hydrological Processes ◽  
Tibet Plateau ◽  
Hydrological Process ◽  
Snow Melt ◽  
Rainfall Runoff

<p>The glacier ratio influences both the contribution of meltwater runoff and the response of the basin's hydrological processes to climate change. In this study, the Karuxung, the Tuotuo and the Babao river basins with glaciers accounting for 20.7%, 2.1% and 0.38% respectively, were selected to study their hydrological processes under the climate change. Based on the daily runoff data of 30 years and MODIS snow cover products, the J2000 model was applied to quantify the contribution of meltwater and rainfall runoff, analyze the temporal and spatial variation characteristics of runoff and clarify the influence of climate change on these three basin. The main findings are as follows: (1) The contribution of glacier and snow melt runoff for the Karuxung, Tuotuo and Babao river basin was 60.7%, 25.3% and 19.9%, respectively. The contribution of rainfall runoff for the three basins was 39.3%, 74.7% and 81.1%, respectively. (2) The peak of glacier and snow melt runoff converted from summer to spring with the glacier ratio decreasing. (3) The runoff supplies in the Karuxung, Tuotuo and Babao river basin were from the 5500m-6500m, 4500m-5500m zone, and 3500m-4500m elevation zone, respectively. (4) The runoff and its components in the Karuxung and Tuotuo river basins showed significant increasing trends while the Babao river basin showed no significant change trends. (5) In the Karuxung river basin with large glacier ratio, the increase in temperature mainly caused the increase of meltwater and runoff, showing a positive impact on runoff. For the Tuotuo and Babao river basin with small glacier ratios, the increase in temperature mainly caused increased evaporation and reduced runoff, showing a negative impact on runoff.</p>

scholarly journals Winter tourism and climate change in the Pyrenees and the French Alps: relevance of snowmaking as a technical adaptation

2018 ◽  
Author(s):  
Pierre Spandre ◽  
Hugues François ◽  
Deborah Verfaillie ◽  
Marc Pons ◽  
Matthieu Vernay ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Projections ◽  
Reference Period ◽  
Winter Tourism ◽  
French Alps ◽  
Ski Resorts ◽  
Rcp 8.5 ◽  
The Alps ◽  
Natural Snow ◽  
Near Future

Abstract. Climate change is increasingly regarded as a threat for winter tourism due to the combined effect of decreasing natural snow amounts and decreasing suitable periods for snowmaking. The present work investigated the snow reliability of 175 ski resorts in France (Alps and Pyrenees), Spain and Andorra under past and future conditions using state-of-the-art snowpack modelling and climate projections. The natural snow reliability (i.e. without snowmaking) elevation showed a significant spatial variability in the reference period (1986–2005) and to be highly impacted by the on-going climate change. The technical reliability (i.e. including snowmaking) is projected to rise by 200 m to 300 m in the Alps and by 400 m to 600 m in the Pyrenees in the near future (2030–2050) compared to the reference period for all climate scenarios. While 99 % of ski lift infrastructures are reliable in the reference period thanks to snowmaking, a significant fraction (14 % to 25 %) may be considered "at risk" in the near future. Beyond the mid century, climate projections highly depend on the scenario with steady conditions compared to the near future (RCP 2.6) or continuous decrease of snow reliability (RCP 8.5). According to the "business as usual" scenario (RCP 8.5), there would no longer be any snow reliable ski resorts based on natural snow conditions in French Alps and Pyrenees (France, Spain and Andorra) at the end of the century (2080–2100). Only 24 resorts are projected to remain technically reliable, all being located in the Alps.

scholarly journals The Tree Height Growth of Most Southern Scot Pine Populations Are Locally Adapted to Drought

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 555
Author(s):  
Natalia Vizcaíno-Palomar ◽  
Noelia González-Muñoz ◽  
Santiago C. González-Martínez ◽  
Ricardo Alía ◽  
Marta Benito Garzón
Keyword(s):  
Climate Change ◽  
Local Adaptation ◽  
Scots Pine ◽  
Tree Height ◽  
Height Growth ◽  
Species Ranges ◽  
Current Climate ◽  
Rcp 8.5 ◽  
Tree Height Growth ◽  
The Impact

Most populations of Scots pine in Spain are locally adapted to drought, with only a few populations at the southernmost part of the distribution range showing maladaptations to the current climate. Increasing tree heights are predicted for most of the studied populations by the year 2070, under the RCP 8.5 scenario. These results are probably linked to the capacity of this species to acclimatize to new climates. The impact of climate change on tree growth depends on many processes, including the capacity of individuals to respond to changes in the environment. Pines are often locally adapted to their environments, leading to differences among populations. Generally, populations at the margins of the species’ ranges show lower performances in fitness-related traits than core populations. Therefore, under expected changes in climate, populations at the southern part of the species’ ranges could be at a higher risk of maladaptation. Here, we hypothesize that southern Scots pine populations are locally adapted to current climate, and that expected changes in climate may lead to a decrease in tree performance. We used Scots pine tree height growth data from 15-year-old individuals, measured in six common gardens in Spain, where plants from 16 Spanish provenances had been planted. We analyzed tree height growth, accounting for the climate of the planting sites, and the climate of the original population to assess local adaptation, using linear mixed-effect models. We found that: (1) drought drove differences among populations in tree height growth; (2) most populations were locally adapted to drought; (3) tree height was predicted to increase for most of the studied populations by the year 2070 (a concentration of RCP 8.5). Most populations of Scots pine in Spain were locally adapted to drought. This result suggests that marginal populations, despite inhabiting limiting environments, can be adapted to the local current conditions. In addition, the local adaptation and acclimation capacity of populations can help margin populations to keep pace with climate change. Our results highlight the importance of analyzing, case-by-case, populations’ capacities to cope with climate change.

scholarly journals Localize the Impact of Global Greenhouse Gases Emissions under an Uncertain Future: A Case Study in Western Cape, South Africa

Earth ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 111-123
Author(s):  
Bowen He ◽  
Ke J. Ding
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Co2 Emissions ◽  
Ghg Emissions ◽  
Future Climate ◽  
Emissions Reduction ◽  
Western Cape ◽  
Emissions Scenarios ◽  
Rcp 8.5 ◽  
The Impact

The growing impact of CO2 and other greenhouse-gas (GHG) emissions on the socio-climate system in the Western Cape, South Africa, urgently calls for the need for better climate adaptation and emissions-reduction strategies. While the consensus has been that there is a strong correlation between CO2 emissions and the global climate system, few studies on climate change in the Western Cape have quantified the impact of climate change on local climate metrics such as precipitation and evaporation under different future climate scenarios. The present study investigates three different CO2 emissions scenarios: Representative Concentration Pathway (RCP) 2.6, RCP 4.5, and RCP 8.5, from moderate to severe, respectively. Specifically, we used climate metrics including precipitation, daily mean and maximum near-surface air temperature, and evaporation to evaluate the future climate in Western Cape under each different RCP climate scenario. The projected simulation results reveal that temperature-related metrics are more sensitive to CO2 emissions than water-related metrics. Districts closer to the south coast are more resilient to severer GHG emissions scenarios compared to inland areas regarding temperature and rainfall; however, coastal regions are more likely to suffer from severe droughts such as the “Day-Zero” water crisis. As a result, a robust drying signal across the Western Cape region is likely to be seen in the second half of the 21st century, especially under the scenario of RCP 8.5 (business as usual) without efficient emissions reduction policies.

scholarly journals Timing and magnitude of future annual runoff extremes in contrasting Alpine catchments in Austria

2021 ◽  
Author(s):  
Sarah Hanus ◽  
Markus Hrachowitz ◽  
Harry Zekollari ◽  
Gerrit Schoups ◽  
Miren Vizcaino ◽  
...  
Keyword(s):  
Climate Change ◽  
High Elevation ◽  
Annual Runoff ◽  
Snow Melt ◽  
Annual Maximum ◽  
Ice Dynamics ◽  
Rcp 8.5 ◽  
Alpine Catchments ◽  
Maximum Flows ◽  
Hydrological Regimes

Abstract. Hydrological regimes of alpine catchments are expected to be strongly affected by climate change mostly due to their dependence on snow and ice dynamics. While seasonal changes have been studied extensively, studies on changes in the timing and magnitude of annual extremes remain rare. This study investigates the effects of climate change on runoff patterns in six contrasting alpine catchments in Austria using a process-based semi-distributed hydrological model and projections from 14 regional climate and global climate model combinations for RCP 4.5 and RCP 8.5. The study catchments represent a spectrum of different hydrological regimes, from pluvial-nival to nivo-glacial, as well as distinct topographies and land forms, characterizing different elevation zones across the Eastern Alps to provide a comprehensive picture of future runoff changes. The climate projections are used to model river runoff in 2071–2100, which are then compared to the 1981–2010 reference period for all study catchments. Changes in timing and magnitude of annual maximum and minimum flows as well as in monthly runoff and snow melt are quantified and analyzed. Our results indicate a substantial shift to earlier occurrences in annual maximum flows by 9 to 31 days and an extension of the potential flood season by one to three months for high-elevation catchments. For low-elevation catchments, changes in timing of annual maximum flows are less pronounced. Magnitudes of annual maximum flows are likely to increase by 2–18 % under RCP 4.5, while no clear changes are projected for four catchments under RCP 8.5. The latter is caused by a pronounced increase in evaporation and decrease in snow melt contributions which offset increases in precipitation. Minimum annual runoff occur 13–31 days earlier in the winter months for high-elevation catchments, whereas for low-elevation catchments a shift from winter to autumn by about 15–100 days is projected. While all catchments show an increase in mean magnitude of minimum flows by 7–30 % under RCP 4.5, this is only the case for four catchments under RCP 8.5. Our results suggest a relationship between the elevation of catchments and changes in timing of annual maximum and minimum flows. For the magnitude of the extreme flows, a relationship is found between catchment elevation and annual minimum flows, whereas this relationship is lacking between elevation and annual maximum flow.

scholarly journals Neglected and Underutilized Fruit Species in Sri Lanka: Prioritisation and Understanding the Potential Distribution under Climate Change

Agronomy ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 34 ◽  
Author(s):  
Sujith S. Ratnayake ◽  
Lalit Kumar ◽  
Champika S. Kariyawasam
Keyword(s):  
Climate Change ◽  
Sri Lanka ◽  
Potential Distribution ◽  
Potential Range ◽  
Fruit Species ◽  
Emissions Scenarios ◽  
Rcp 8.5 ◽  
Food Security And Nutrition ◽  
Suitable Area ◽  
The Impact

Neglected and underutilized fruit species (NUFS) can make an important contribution to the economy, food security and nutrition requirement for Sri Lanka. Identifying suitable areas for cultivation of NUFS is of paramount importance to deal with impending climate change issues. Nevertheless, limited studies have been carried out to assess the impact of climate change on the potential distribution of NUFS. Therefore, we examined the potential range changes of NUFS in a tropical climate using a case study from Sri Lanka. We prioritized and modeled the potentially suitable areas for four NUFS, namely Aegle marmelos, Annona muricata, Limonia acidissima and Tamarindus indica under current and projected climates (RCP 4.5 and RCP 8.5) for 2050 and 2070 using the maximum entropy (Maxent) species distribution modeling (SDM) approach. Potentially suitable areas for NUFS are predicted to decrease in the future under both scenarios. Out of the four NUFS, T. indica appears to be at the highest risk due to reduction in potential areas that are suitable for its growth under both emissions scenarios. The predicted suitable area reductions of this species for 2050 and 2070 are estimated as >75% compared to the current climate. A region of potentially higher climatic suitability was found around mid-county for multiple NUFS, which is also predicted to decrease under projected climate change. Further, the study identified high-potential agro-ecological regions (AERs) located in the mid-country’s wet and intermediate zones as the most suitable areas for promoting the cultivation of NUFS. The findings show the potential for incorporating predictive modeling into the management of NUFS under projected climate change. This study highlights the requirements of climate change adaptation strategies and focused research that can increase the resilience of NUFS to future changes in climate.

scholarly journals Predicting the Water Requirement for Rice Production as Affected by Projected Climate Change in Bihar, India

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3312
Author(s):  
Ranjeet K. Jha ◽  
Prasanta K. Kalita ◽  
Richard A. Cooke ◽  
Praveen Kumar ◽  
Paul C. Davidson ◽  
...  
Keyword(s):  
Climate Change ◽  
Irrigation Water ◽  
Water Demand ◽  
Climate Scenario ◽  
Baseline Period ◽  
Water Requirement ◽  
Rice Production ◽  
Climate Change Scenarios ◽  
Current Climate ◽  
Rcp 8.5

Climate change is a well-known phenomenon all over the globe. The influence of projected climate change on agricultural production, either positive or negative, can be assessed for various locations. The present study was conducted to investigate the impact of projected climate change on rice’s production, water demand and phenology for the state of Bihar, India. Furthermore, this study assessed the irrigation water requirement to increase the rice production by 60%, for the existing current climate scenario and all the four IPCC climate change scenarios (RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5) by the 2050s (2050–2059). Various management practices were used as adaptation methods to analyze the requirement of irrigation water for a 60% increase in rice production. The climate data obtained from the four General Circulation Models (GCMs) (bcc_csm1.1, csiro_mk3_6_0, ipsl_cm5a_mr and miroc_miroc5) were used in the crop growth model, with the Decision Support System for Agrotechnology Transfer (DSSAT) used to simulate the rice yield, phenological days and water demand under all four climate change scenarios. The results obtained from the CERES-Rice model in the DSSAT, corresponding to all four GCMs, were ensembled together to obtain the overall change in yield, phenology and water demand for 10 years of interval from 2020 to 2059. We investigated several strategies: increasing the rice’s yield by 60% with current agronomic practice; increasing the yield by 60% with conservation agricultural practice; and increasing the rice yield by 30% with current agronomic practice as well as with conservation agricultural practices (assuming that the other 30% increase in yield would be achieved by reducing post-harvest losses by 30%). The average increase in precipitation between 2020 and 2059 was observed to be 5.23%, 13.96%, 9.30% and 9.29%, respectively, for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5. The decrease in yield during the 2050s, from the baseline period (1980–2004), was observed to be 2.94%, 3.87%, 4.02% and 5.84% for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, respectively. The irrigation requirement was predicted to increase by a range of 39% to 45% for a 60% increase in yield using the current agronomic practice in current climate scenario and by 2050s with all the four climate change scenarios from the baseline period (1980–2004). We found that if we combine both conservation agriculture and removal of 30% of the post-harvest losses, the irrigation requirement would be reduced by 26% (45 to 19%), 20% (44 to 24%), 21% (43 to 22%), 22% (39 to 17%) and 20% (41 to 21%) with current climate scenario, RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5 conditions, respectively. This combination of conservation practices suggests that the irrigation water requirement can be reduced by a large percentage, even if we produce 60% more food under the projected climate change conditions.

scholarly journals Hydropower Potential in the Alps under Climate Change Scenarios. The Chavonne Plant, Val D’Aosta

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2011
Author(s):  
Tommaso Duratorre ◽  
Giovanni Bombelli ◽  
Giovanni Menduni ◽  
Daniele Bocchiola
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Hydrological Cycle ◽  
Climate Change Scenarios ◽  
Snow Melt ◽  
Half Century ◽  
Ice Melt ◽  
Hydropower Potential ◽  
Hydropower Production ◽  
The Alps

Present and prospective climate change will likely affect the hydrological cycle in sensitive areas, such as the Alps, thus impacting water-based activities. A most representative example is hydropower production, i.e., exploitation of water to produce energy. In the Italian Alps hydropower is strictly dependent upon water from snow and ice melt, and both are decreasing in response to global warming. Here, we study the effects of potential climate change scenarios at 2100 upon hydropower production from the Chavonne plant, in Valle d’Aosta region of Italy, a run-of-the-river (ROR) plant taking water from two high altitude glacierized catchments of Val di Cogne, and Valsavarenche. We use Poli-Hydro, a state-of-the-art hydrological model to mimic the hydrological budget of the area, including ice and snow melt share. Projections of the hydrological budget were built until 2100 by means of selected climate change scenarios, under proper downscaling. We used runs of three General Circulation Models (GCMs), EC-Earth, CCSM4, and ECHAM6.0 under three Representative Concentration Pathways RCP 2.6, RCP 4.5, and RCP 8.5 from AR5 of IPCC, and of their updated version under four Shared Socio-Economic Pathways SSP1 2.6, SSP2 4.5, SSP3 7.0, and SSP5 8.5 from AR6. We then assessed hydropower production changes against a recent control run CR period (2005–2015). Mean annual flow is estimated at 14.33 m3 s−1 during CR, with ice melt contribution ca. 2%, and snow melt contribution ca. 44%. Ice cover in 2005 was estimated as 19.2 km2, reaching in 2015, 9.93 km2. Mean hydropower production was estimated at 153.72 GWh during the CR. Temperature would largely increase throughout the century (+0.93 °C on average at the half century, +2.45 °C at the end of the century). The ice covered area would be largely depleted (ca. −86%, −94% respectively), with reduced contribution of ice melt (0.23%, <0.1%, respectively) and snow melt (ca. 37%, 33%, respectively). Precipitation would show uncertain patterns, and hence incoming discharge at the plant would erratically vary (−29% to +24% half century, −27% to +59% end of century). Hydropower production displays a large dependence upon monthly discharge patterns, with mostly positive variations (+2.90% on average at half century, +6.95% on average at end of century), with its change driven by exceedance of plant’s capacity.

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