Roundup: The Hydropower Potential In Glacier Retreat, A Glacier Children’s Book, and How Glaciers Affect Kyrgyz Pasture Selection

Large Hydropower and Water-storage Potential in Future Glacier-free Basins

A major study published in Nature takes a global look at the hydropower potential of deglacierized water basins. As glaciers retreat in high mountain areas, they sometimes expose areas which can be used as hydropower reservoirs by holding snowmelt and runoff from rain. From the abstract:

“Climate change is causing widespread glacier retreat, and much attention is devoted to negative impacts such as diminishing water resources, shifts in runoff seasonality, and increases in cryosphere-related hazards. Here we focus on a different aspect, and explore the water-storage and hydropower potential of areas that are expected to become ice-free during the course of this century…Although local impacts would need to be assessed on a case-by-case basis, the results indicate that deglacierizing basins could make important contributions to national energy supplies in several countries, particularly in High Mountain Asia.”

Read the study here.

The O’Shaughnessy Dam in California’s deglacierized Hetch Hetchy Valley is a source of hydropower and water for the city of San Francisco (Source: King of Hearts/WikiCommons).

A Glacial Erratic is the Star of a New Children’s Book

A children’s book entitled Old Rock (Is Not Boring), written an illustrated by Deb Pilutti, features rocks and glaciers. From a review of Old Rock (Is Not Boring):

“Old Rock sits “in the same spot, at the edge of a clearing in the middle of a pine forest” every day, and the other forest residents insist the rock must be bored. After Hummingbird, Spotted Beetle, and Tall Pine regale Old Rock with tales of their adventures, Old Rock relays a rich history in which he was shot from a volcano, hid dinosaurs from predators, survived an ice age, traveled frozen in a glacier, and rolled onto plains populated with mastodons.”

Old Rock (is not boring) is a children’s book written and illustrated by Deb Pilutti (Source: Deb Pilutti/Twitter)

Kyrgyz Herders Follow Glacial Melt, Study Finds

Kyrgyz herders in Central Asia use proximity to glaciers as a criteria for selecting which kinds of pasture are best for their flocks, according to a recent study in the journal Ecology and Society. From the abstract:

“Consensus on the state of rangelands is often elusive. This is especially true in the primarily agropastoral former Soviet republic of Kyrgyzstan. Some argue Kyrgyz rangeland is being rapidly degraded by overgrazing. However, poor data and climatic changes confound this assessment. Thus there is contention amongst researchers, state officials, and local agropastoralists about the etiology and appropriate degree of concern regarding changes in flora and landscape patterns. This lack of consensus makes pasture management difficult for local elected managers. In this study, we use audiovisual primes, structured interview tasks, and consensus analysis to examine the degree of agreement among local agropastoralists of Naryn oblast about (a) the nature of several degradation-ambiguous plant and landscape types found in the area, and (b) indicators of “good” pasture. We find relatively little interparticipant agreement on high-resolution details, but a pattern of consensus regarding (i) a refutation of select species as indicators of degradation, as well as (ii) apparent shared heuristics for determining what makes for good, versus bad, pasture. We consider socio-historical and cognitive drivers of these patterns, and close with a discussion of implications for management.

Read the full study here.

High summer pasture in Naryn oblast (Source: Levine et al/Ecology and Society).

Read More on GlacierHub:

Indigenous Activist Among Those Killed In Iran’s Takedown of Civilian Airliner

What the Yak Herders of Northern Bhutan Are Saying About Global Warming

Mongolia’s Cashmere Goats Graze a Precarious Steppe

Large storage potential in future ice-free glacier basins

Global warming will cause substantial glacier retreat for the majority of the world’s glaciers over the next few decades. This will not only spell the end for some magnificent natural monuments, but also importantly affect the water cycle. In high-​mountain regions, these ice masses act as reservoirs feeding water to large river systems, and balancing seasonal discharges.

Without glaciers, rivers would carry considerably less water in summer, which would have noticeable consequences for water availability, energy production and agriculture in many regions of the world. Researchers had previously discussed the idea of compensating the shrinking storage function of glaciers with reservoirs (see Zukunftsblog – in German only).

A group of glaciologists from ETH Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL is now again engaging in the discussion about the dwindling ice: in a study published in Nature, they investigate the global potential for storing water and producing hydropower in presently-​glacierised areas that will become ice-​free within this century.

The Gebidem arch dam in Switzerland is partially fed by meltwater from the Aletsch Glacier, the longest glacier in the Alps (Source: WikiCommons).

Using glaciers as reservoirs

In their study, the research team around Daniel Farinotti, Professor of Glaciology at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at ETH Zurich and at WSL, analysed about 185,000 glaciers. For these sites they calculated a maximum theoretical storage potential of 875 cubic kilometers (km3) and a maximum theoretical hydropower potential of 1350 terawatt hours (TWh) per year.

“This theoretical total potential corresponds to about one third of current hydropower production worldwide. But in reality, only part of it would be realisable”, explains Farinotti.

In order to obtain a more realistic estimate, the researchers conducted an initial suitability assessment for all sites. They identified around 40 percent of the theoretical total potential as “potentially” suitable, equalling to a storage volume of 355 km3 and a hydropower potential of 533 TWh per year. The latter corresponds to around 13 percent of the current hydropower production worldwide, or nine times Switzerland’s annual electricity demand.

“Even this potentially suitable storage volume would be sufficient to store about half of the annual runoff from the studied glacierised basins,” Farinotti says. Assuming an average climate scenario, about three-​quarters of the storage potential could become ice-​free by 2050.

Cautious estimate of potential

For their analysis, the glaciologists used a global glacier inventory and placed virtual dams at the current terminus of each glacier with an area of more than 50,000 square meters located outside the Subantarctic. They then optimised the size of the reservoirs by appropriate dam positioning and height. In doing so, they minimised the reservoirs’ impact on the landscape and did not just maximise economic return. The team used digital elevation models of the subglacial terrain and combined them with a glacier evolution model to determine the storage volume of the 185,000 glaciers they had selected.

In the suitability analysis that followed, the researchers assessed the sites based on several ecological, technical and economic criteria: “On this basis, we ruled out the most unsuitable sites; this enabled a more realistic assessment,” explains co-​author Vanessa Round, who was affiliated at both institutions and had a pivotal role in the study. She also adds that it is neither realistic nor desirable to build a dam for every glacier.

A model for the future?

The team also stresses that local impacts should be assessed on a case-​by-case basis. Nevertheless, the results indicate that deglacierised basins could significantly contribute to national energy supply and water storage in a number of countries, particularly in High Mountain Asia.

Among the countries with the largest potentials are Tajikistan, where the calculated hydropower potential could account for up to 80 percent of current electricity consumption, Chile (40 percent) and Pakistan (35 percent). In Canada, Iceland, Bolivia and Norway, the potential equals 10–25 percent of their current electricity consumption. For Switzerland, the study shows a potential of 10 percent.

Meanwhile, the Swiss Federal Office of Energy has recently revised downwards the expansion potential for Swiss hydropower. This is mainly because of revised estimates for the impact of stricter regulations on environmental flows, and because the potential of small-​scale hydropower is now considered to be lower than it was in 2012. However, in its assessment, the SFOE explicitly excluded the hydropower potential that could arise from future ice-​free basins. For this reason, the glaciologists led by Farinotti do not see a contradiction to their results, as the two studies cannot be directly compared.

This post was written by Michael Keller and originally published by ETH Zurich.

Read More on GlacierHub

Damming Switzerland’s Glaciers

Trump’s Interior Pick Wants to Heighten California Dam

Video of the Week: Artificial Glaciers for Himalayan Desert