Rhone Watershed At Risk from Climate Change

Rhône's source - Furkapass - Switzerland. Courtesy of Marle M./Flickr
Rhône’s source – Furkapass – Switzerland. Courtesy of Marle M./Flickr

Researchers, policy experts and agency managers have long recognized that water resources are influenced both by global climate processes and by regional environmental dynamics.  In a close examination of an economically important region in the Swiss Alps, reseachers recently found that land use change have a much smaller impact on glacier and snow melt than climate change. An assessment of stream flow during different times of year also revealed a lower peak flow and an earlier start to peak flows driven by melting snow and glaciers. The findings support previous research on annual melt in the region, and strengthen the understanding of the causes of the changes. By emphasizing the importance of climate change, this research can help shape policies to address declining water resources.

Water flowing from high altitudes in the Alps plays a significant role in Switzerland’s tourism industry, hydroelectricity production and feeds into the Rhone River and Lake Geneva. Every summer, runoff from snowmelt and the Rhone Glacier enters the Rhone River, which, at 167.5 kilometers in length, is one of the longest and most important in the country.

“The entire upper Rhone watershed is of paramount importance because 11 large hydropower plants are located in this watershed,” the authors wrote. “Therefore, a model could lead to a better understanding of the current inflow situation and scenario analysis could help in planning better downstream water management.”

By using data to create land maps and developing models, researchers from Stanford University, the University of Geneva and the Wegener Center for Climate and Global Change in Graz, Austria, found that if the world continues on a business as usual trajectory in which greenhouse gas emissions are not curbed, streamflow from the Swiss Alps will be greatly reduced as a result of glacier loss. Climate change will also lead to reduced agricultural production, which in turn will promote forest growth as farmers take lands out of cultivation. This change will also impact stream flow, since trees will absorb precipitation and reduce runoff into streams, though the impact of climate change was found to be more significant. This importance could be related to lower levels of land use change in high altitudes, the authors concluded.

The Rhone Glacier, courtesy of Ivo Jansch/Flickr.
The Rhone Glacier, courtesy of Ivo Jansch/Flickr.

Models were developed to assess glacier melt and land use change for two periods, between 2011 and 2025, and between 2026 and 2050. The models included a number of  physical processes, including ocean precipitation, transpiration, snow melt and glacier melt. Researchers also used a Soil and Water Assessment Tool to determine water flow.

“Since the runoff in this watershed is driven by snow and glacier melt, the early melt could lead to several consequences, the most severe of which is on hydropower based energy production,” the authors wrote. “Early melt will cause an early filling of reservoirs and result in a shortage during peak flows. Therefore, the result obtained from this study can be useful for water management in the Rhone Valley.” In this way, their findings correspond to other studies elsewhere in  Europe, in Latin America and Asia, which also show that glacier retreat will have negative effects on hydropower–a source of renewable energy which could reduced the dependence of global economies on fossil fuels. Studies such as these are thus of great importance for formulating responses to climate change.

 

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Roundup: Swiss Blankets and Data, Participation in Tajikistan

Blankets covering Swiss glacier to halt ice melt is a temporary fix

Blankets cover Swiss glacier
Photo courtesy of nycity.today

“From a distance, the Rhone glacier seems perfect, but when seen closely, the surface is covered with white blankets for slowing down the melting of the rapidly retreating ice. The dusty, white fleece covers a huge area near the glacier’s edge. But there is a Swiss tourist attraction hidden under the blankets. It is a long and winding ice grotto with shiny blue walls and a leaky ceiling that has been carved into the ice here every year since 1870.

While poking at a piece of cloth lying besides the way that leads toward the cave’s opening, David Volken, a glaciologist working with the Swiss environment ministry, said that for the last eight years, they have been covering the ice cave with such blankets to decrease the ice melt.”

Click here to read more.

A participatory method to enhance the collective ability to adapt to rapid glacier loss: the case of mountain communities in Tajikistan

2“A 2010 participatory case study in the Zerafshan Range, Tajikistan, disclosed a local lack of awareness of climate change and its consequences. We present a social learning method based on scenarios and visualization. The process exposed a remarkable potential for comprehensive adaptation, including in water harvesting, choice of crops and livestock, environmental enhancement, skills and conflict management. We recommend the approach as a model to promote local collective adaptive capacity development. The case study revealed high risks of massive out-migration from mountain villages if adaptation starts too late: countries with a high proportion of mountain agriculture might see significant losses of agricultural area, a reduction in food production and an increase in conflicts in areas where immigration occurs.”

To read more about the study and its findings, click here.

Influence of land use and climate change in glacial melt and hydrological process

“Land use and climate change play a significant role in hydrological processes. This study assesses the impact of land use and climate change in a snow and glacier dominated high altitude watershed, located in the southwestern part of Switzerland…. Our study shows a decrease in the summer peak flow and an early start of the melt driven peak flow. The major change observed in this study is the rising period of the hydrograph, i.e. in May and June an early shift is observed in the discharge. Independent analysis from land use change and climate change shows that the peak flow reduction occurs as a result of land use change, but the peak flow together with the timing of peak flow occurrence is also influenced by climatic change. The combined effect suggests a reduction of peak flow and early melt driven streamflow in the future. Information obtained from this study can be useful for water managers, especially for the hydropower based energy production sector in the Rhone watershed.”

To learn more, click here.

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