Roundup: Chemistry, Dams and Elevations

Roundup: Meltwater Chemistry, Hydroelectric Dams and Glacier Elevation


Diurnal Changes in the Chemistry of Glacier Meltwater

From Chemosphere: “An evaluation of glacial meltwater chemistry is needed under recent dramatic glacier melting when water resources might be significantly impacted. This study investigated trace elements variation in the meltwater stream, and its related aquatic environmental information, at the Laohugou glacier basin (4260 m a.s.l.) at a remote location in northeast Tibetan Plateau… Results showed evident elements spatial difference on the glacier surface meltwater, as most of the elements showed increased concentration at the terminus compared to higher elevations sites… The accelerated diurnal and temporal snow-ice melting (with high runoff level) were correlated to increased elemental concentration, pH, EF (enrichment factor,the minimum factor by which the weight percent of mineral in is greater than the average occurrence of that mineral in the Earth’s crust) and elemental change mode, and thus this work is of great importance for evaluating the impacts of accelerated glacier melting to meltwater chemistry and downstream ecosystem in the northeast Tibetan Plateau.”

Read more about it here.

Accelerated melting affects the chemistry of glacier meltwater streams (Source: Shayon Ghosh/Creative Commons)
Accelerated melting affects the chemistry of glacier meltwater streams (Source: Shayon Ghosh/Creative Commons)


Locals Oppose Dam Construction in the North Western Himalayas

From the International Journal of Interdisciplinary and Multidisciplinary Studies: “Since early 1970s dam development projects witnessed severe opposition in India. The remote tribal groups and rural population rejected the idea of large scale displacement, land alienation, economic insecurity and endless suffering that came along with ‘development’ projects… In recent past the construction of hydroelectricity projects has faced severe opposition in the tribal regions in Himachal Pradesh. The locals in Kinnaur are facing numerous socio-economic and environmental consequences of these constructions in fragile Himalayan ecology… More than 30 hydro projects proposed in Lahaul & Spiti are also being challenged by the people in Chenab valley… The paper summarises the ongoing struggle and diverse implications added with climate change in the rural structures.”

Read more about local opposition to these projects here.

Karcham Wangtoo Hydroelectric Plant in Kinnaur (Source: Sumit Mahar/Creative Commons).
Karcham Wangtoo Hydroelectric Plant in Kinnaur (Source: Sumit Mahar/Creative Commons).


Uneven Changes in Ice Sheet Elevation in West Antarctica

From Geophysical Research Letters: “We combine measurements acquired by five satellite altimeter missions to obtain an uninterrupted record of ice sheet elevation change over the Amundsen Sea Embayment, West Antarctica, since 1992… Surface lowering has spread slowest (<6 km/yr) along the Pope, Smith, and Kohler (PSK) Glaciers, due to their small extent. Pine Island Glacier (PIG) is characterized by a continuous inland spreading of surface lowering, notably fast at rates of 13 to 15 km/yr along tributaries draining the southeastern lobe, possibly due to basal conditions or tributary geometry… Ice-dynamical imbalance across the sector has therefore been uneven during the satellite record.”

Read more about the changes in ice sheet elevation here.

The calving front of Pine Island Glacier (Source: NASA/Creative Commons).
The calving front of Pine Island Glacier (Source: NASA/Creative Commons).

India’s Hydroelectric Plans Threaten Local Comunities


Indigenous Buddhist tribes in northeast India are protesting government plans to build fifteen new hydroelectric sites along their settlement region. The Monpa tribe, which lives along the Tawang river basin in over 234 scattered settlements in Arunachal Pradesh, fears that the hydroelectric projects will affect their religious sites and monasteries, as well as the region’s springs, and biological diversity, which carry large cultural significance for the tribe. The region is also at risk of Glacial Lake Outburst Floods (GLOFs), which could have hazardous impacts on hydroelectric projects.

Black Cranes
Black-necked cranes by a lake in Tibet. Courtesy of Purbu Zhaxi/Xinhua Press/Corbis

The government is proceeding with the construction of one particularly contentious hydroelectric site: a 780MW station along the Nyamjang Chhu river that threatens a cultural and religiously significant migration site of endangered black-necked cranes. This site will occupy the middle of a 3-km stretch of the Nyamjang Chhu river, which is partially fed by the region’s glaciers and along which eight black-necked cranes reside during their winter migration.  The Monpa eagerly await the birds’ arrival, and revere their species as the reincarnation of the sixth Dalai Lama.

In late July of 2015, the Save Mon Region Federation sent a letter to the Expert Appraisal Committee of the ministry, accusing NJC Hydropower, the independent company building the Nyanjan Chhu hydroelectric site, of purposely concealing information about the black-necked cranes’ wintering site. Allegedly, the company didn’t cooperate with the study’s researchers until the end of winter, when the black-necked cranes had left their wintering site.

A Monpa monk spins prayer wheels at Tawang monastery
A Monpa monk spins prayer wheels at Tawang monastery. Photo courtesy of Anupam Nath/AP

“The hydroelectric projects will totally destroy natural habitats in the region,” Asad Rahmani, scientific adviser of the Bombay Natural History Society, told the Guardian. “When planning such projects, we’re not paying attention to their impact on local culture. The electricity is for people like us in the cities, but all the damage is suffered by the local people.”

In addition to going ahead with the highly disputed site placement, the Dehli government has plans for another fourteen proposed hydroelectric projects in the Tawang region. These projects are part of major government efforts to bring power to the 300 million people living without electricity by 2022. The government will also increase solar, wind and coal generation in the next seven years.

“We don’t need so many hydel projects to meet the electricity demand of our people,” Save Mon Region Federation’s general secretary, Lobsang Gyatso, told the Times of India. “Small hydro-projects would suffice. All these large dams are meant to generate electricity to be sold outside, at the cost of our livelihoods and ecology.”

To express concerns about the new hydroelectric plans, villagers in the Tawang region organized a large rally in December of 2012. The protesters alleged that the government had developed hydroelectric projects with private utility developers without proper consent from the residents in the region. The region currently maintains a ban against public gathering.

In addition, the relatively unexplored, mountainous region in the Eastern Himalayas is especially prone to the risk of Glacial Lake Outburst Floods (GLOFs), as are most regions of this type, which poses risky problems to hydroelectric development.

GLOFs are one of the major hazards of mountainous, glacial regions, especially those susceptible to climate change. Tawang’s lakes and rivers are mainly supplied by snowmelt and the melting glaciers of the Himalayas. The lakes, while usually dammed by end-moraines, have a tendency to flash flood, which induces large volumes of flowing water, large quantities of sediment runoff, as well as potential flowing boulders and the risk of washing away mountain valleys. GLOFs are often responsible for catastrophic flooding, large losses of property, and human life.

While the region’s dams have a combined capacity of about 2800 MW of power, a recent study stated that GLOFs and their associated risk are likely to have a “direct impact” on the commissioned hydropower projects in the region, as well as on the Monpa population living downstream of the glacial lakes and hydroelectric projects.

The study aimed to detect potential dangerous lakes to proposed hydroelectric sites, as well as to quantify the volume of water discharge and to predict the hydrograph, or rate of flow versus time, at the lake sites at risk of GLOFs.  The researchers estimated that at peak flow, flooding at one particular dammed lake likely of flooding would take as little as an hour and ten minutes to reach a downstream hydroelectric site, posing great risk to the site. Despite promises from the governmental parliament, no public consultation on the Tawang river basin study report has yet been held.

The Monpa protestors remain focused on the threats the hydroelectric sites pose to their cultural and religious traditions. Each of the 234 Tawang settlements along the river will be affected by at least one hydropower plant, and construction for the sites will demolish roughly 615 acres of forest. Monpa residents also fear the disruption of sacred pilgrimage sites and springs.

Climate Change Brings Global Energy Concerns

An image of the Kali Gandaki Hydroelectric Plant in Nepal
Kali Gandaki Hydroelectric Plant in Nepal is an example of new hydropower projects in the Himalayas. Image by Asian Development Bank via Flicker

Global reliance on hydroelectric energy production has only increased in the 21st century, even as our supply of hydropower has become increasingly uncertain due to climate change impacts, including glacial retreat. South Asia is a clear example: due to the high cost and political risks of importing fuels like oil or coal, countries in this region have increasingly turned to hydroelectric power for domestic energy production. But changes to the Himalayan hydro-ecosystem could severely disrupt future hydroelectric development in South Asia.

Today, large regional electrical grids feed most global energy demand. To maintain constant supply and meet demand as efficiently as possible, different “tiers” of power plants tend to work together. “Base load” power plants, such as nuclear and coal generators, are most efficient when providing a constant supply of energy around the clock, as opposed to in short bursts to meet peak demand, and so form the backbone of most electric grids. “Load following” power plants are used to adapt to short-term changes in demand, typically shutting down at night or early morning. Examples include natural gas or diesel and renewable power plants. “Peaking power” plants can start and stop very quickly but are far less efficient than base load plants at longer timescales and are more expensive to run than load following plants. They typically come online for only a few hours a day to meet peaks in energy demand. Diesel and gasoline internal combustion engines are examples.

A map of Hydroelectric power generation in and around the US
Glacial fed hydropower is a significant resource for areas like the Pacific Northwest and British Columbia

Hydroelectric generators can theoretically be used to fill any of these roles, depending upon the availability of water, the size of the reservoir, and the installed capacity. For this reason variations in hydro-ecosystems have a large impact on the energy potential available to such generators. If a hydroelectric plant is supplying base load energy, low stream flow can lead to power outages. If such a plant is used to supply peak needs, declines in water supplies at the wrong times can cause voltage drops or brownouts. Conversely, if the reservoir is too full due to heavy rain or snowmelt, spillways have to be opened and the energy often cannot be used at all. For these reasons hydroelectric plants are most commonly used as load following plants. Some even pump water back up river into reservoirs as a form of energy storage if production is high when demand is low.

In the Himalayas, hydropower is at grave risk, and yet there is virtually no supplementary base load power available, and little ability to purchase energy from other sources. As Himalayan glaciers melt at unprecedented rates, springtime stream flows have become more intense and unpredictable, while the risks of glacial lake outburst floods and landslides are growing. The severe inconsistency of the water supply could even cause hydroelectric projects to fail, flooding downstream communities. Ultimately, investments in hydroelectric power in the region may be disproportionate to the amount of energy that these plants will realistically be able to produce, given the ecosystem risks.

Picture of Hoover Dam
The Hoover Dam on the Colorado River will be affected by decreased streamflows over the coming decades

Although South Asia is in a notably precarious position, such concerns are not uniquely Himalayan.  In fact, according to a study by Schaefli et al., the net effect of global warming in Switzerland will be to noticeably reduce hydroelectric production, which is a serious problem for a country where 75% of electricity comes from hydroelectric power. Another 2014 study on Swiss hydropower by Ludovic Gaudard et al. has warned that increased water scarcity may lead to competition for water uses, further limiting water available for energy production. As such, the country has been taking measures to insure energy resilience, managing its hydro projects more closely and investing in other forms of renewable energy. According to the results of a project by the Swiss Sustainable Water Management National Research Programme, more careful water management practices could make up for increasing stream flow uncertainty.

In the US Pacific Northwest, scientists are advocating for greater attention to the ways in which climate uncertainty will affect their energy resources. Matthew S. Markoff and Alison C. Cullen find in a recent study that the region’s energy grid will be impacted by global warming as soon as 2020. According to the EPA, on the American Colorado River, a 1% reduction in stream flow from climate change can reduce electricity output from the various hydroelectric plants that run along it by as much as 3%. And in California, a report from the Department of Water Resources states that:

“Climate change will reduce the reliability of California’s hydroelectricity operations . . . changes in the timing of inflows to reservoirs may exceed generation capacity, forcing water releases over spillways and resulting in lost opportunities to generate hydropower. Higher snow elevations, decreased snowpack, and earlier melting may result in less water available for clean power generation during hot summer months. . .”

An image of the dry Folsom Dam reservoir
Dry lakes can’t produce any power. Folsom Dam, Sacramento, California 200 MW installed hydropower capacity. By Dan Brekke with KQED

The report goes on to outline management, policy and funding measures that should be taken to prepare for this reality. Many of these measures are similar to the measures outlined in the Swiss and Pacific Northwest reports.

In each case, the recommended measures are relatively nonspecific, however: increased attention to the uncertainty, and the implementation of increased security standards to protect communities from severe floods and sediment build up. Safety standards can be more easily addressed through the reinforcement of reservoirs, damns and levees, to prepare them for more sporadic and intense stream flows. To address uncertainty, the reports recommend preparing to adapt, and increasing the availability of other forms of renewable energy.

As the world faces widespread glacial retreat and growing climate uncertainty, it is becoming imperative for public and regulatory agencies to take into consideration how climate change will affect energy resources and public safety. This is especially true considering that hydroelectric power is currently the world’s largest source of renewable energy, and that sources of nonrenewable energy are depleting. As the industrialized world publishes studies, drafts plans, and prepares to deal with these risks, industrializing nations like those in South Asia do not always have the same flexibility. Moving forward, different regions of the world must work together to assure the safety of dams and reservoirs, the resiliency of electrical grids, and the sustainability of energy supply.