Posts Tagged "glof"

Palcacocha Icefalls Demonstrate Hazard Vulnerabilities in Peru

Posted by on Jun 6, 2017 in All Posts, Featured Posts, News, Policy and Economics, Science | 1 comment

Palcacocha Icefalls Demonstrate Hazard Vulnerabilities in Peru

Spread the News:ShareRecent Calving Events at Lake Palcacocha In the last week, calving events at Lake Palcacocha in the Peruvian Andes released masses of ice from a glacier on Mount Pucaranra. The ice fell into the lake, sending waves across the lake that destroyed infrastructure designed to prevent dangerous outburst floods. Fortunately, the waves were not high enough to overtop the moraine dam and send floodwaters downstream, where they could have taken many lives and damaged urban infrastructure. A glacial lake outburst flood from Palcacocha devastated Huaraz, the largest city in the region, in 1941, killing about 5,000 people. Other, more recent, glacier floods in the region have also been very destructive. Marco Zapata, the director of glacier research at INAIGEM, the Peruvian National Institute of Research on Glaciers and Mountain Ecosystems, spoke about the events recently in a press conference reported in the Peruvian daily El Comercio. A Spanish-language video of the full press conference is available online. Zapata indicated that the calving event occurred around 8 p.m. on May 31. The resulting waves, three meters in height, were strong enough to move and damage ten large pipes, rendering them inoperable. These pipes, known locally as “syphons,” are designed to draw water from the lake at times when its level is high; in this way, they were thought to reduce flood risk significantly. They had been a point of local pride, seen as a successful application of modern technology to protect against the dangers to which the region has long been subject. Zapata mentioned that the waves also destroyed several gauges and a sensor which measures lake levels. And the event was not an isolated one, at least according to a regional newspaper, which reported a second calving event at 5:40 a.m. on June 2. Representatives of INAIGEM and two other organizations, the National Water Authority and the local municipality of Independencia, visited the lake a few days later. They found that the workers on Pucarthe site had restored two of the drainage pipes. These officials anticipated that the other eight will soon be functional.  Zapata and the other authorities called for increased investment in infrastructure at the lake to reduce the risks of a flood. They estimated that an expenditure of US $6 million would prevent about $2.5 billion in potential damages, including a hydroelectric plant and irrigation facilities on Peru’s desert coast; it would also protect the lives of the 50,000 people who live in the potential flood zone. The Causes of the Calving Events These events were not entirely unexpected. Marcelo Somos Valenzuela, a postdoctoral fellow at the Northeast Climate Science Center at the University of Massachusetts, is the lead author of a study, published last year in the journal Hydrology and Earth System Sciences, which concluded “there is consensus among local authorities, scientists and specialists that Lake Palcacocha represents a glacier lake outburst flood hazard with potentially high destructive impact on Huaraz.” This paper also stated that a “small avalanche” like the ones that recently occurred are “the highest likelihood event” and that they would “produce significantly less inundation.”  Somos Valenzuela wrote to GlacierHub, “There are empirical models and hydrodynamic models which provide estimates of the height of the wave in the lake… In this case, it seems that the ice-fall was small, and 3 meters is a reasonable estimate of the wave height.” Moreover, several sources indicated high risks at this time of year. Noah Walker-Crawford, an anthropologist at the University of Manchester, spoke recently with the workers at the drainage site at the lake. He wrote to GlacierHub, “According to the people who work at the...

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A Visit to the Source of a Recent Glacier Flood in Nepal

Posted by on May 17, 2017 in All Posts, Classroom Hub, Featured Posts, Interviews, News | 0 comments

A Visit to the Source of a Recent Glacier Flood in Nepal

Spread the News:ShareAlton Byers discussed a recent glacier hazard in Nepal with GlacierHub. Byers is a senior research associate at the Institute of Arctic and Alpine Research at the University of Colorado and co-manager of High Mountains Adaptation Partnership (HiMAP). He has been recognized as an Explorer by National Geographic. The account below is based on interviews with Byers and emails from Dhananjay Regmi, a geographer at Tribhuvan University in Kathmandu. On May 2, Daene McKinney, Dhananjay Regmi and Alton Byers flew from Dingboche over the Sherpani Col and into the upper Barun valley in the eastern Himalayas of Nepal in an effort to determine the source of an April 20 flood. Dorje Sherpa, a resident of Yangle Kharka, reported that the lake burst around 1 p.m., flooding down the Barun River, and reached his village about a half-hour later. The settlements of Langmale, Zak Kharka and Rephuk Kharka remained largely undamaged, as did lodges in the area, but Yangle Kharka suffered a loss of at least three buildings and many hectares of valuable grazing land. Tematang, further downstream, is located on a high terrace and was fortunately spared damage. However, all local bridges were washed away. The flood arrived at the confluence of the Barun and Arun Rivers around 4 p.m., where the debris dammed the Arun River, forming a temporary lake 2-3 km long. This setting is remote, a two-day walk from the district capital of Khandbari. The lake presented a serious threat, since it would have created a second, more destructive flood in the densely populated areas downstream had it breached the dam. The government response was swift. Police reached the site on the morning of April 21 and started to plan how to protect the endangered communities. Deputy Prime Minister and Minister for Home Affairs Bimalendra Nidhi issued a directive to open the dam in order to reduce the threat of flooding. The Natural Disaster Rescue Committee, an organization within the Nepali Ministry of Home Affairs, met in Kathmandu to discuss the situation. Fortunately, the lake began to drain spontaneously around 2 p.m. on April 21, with some local flooding below, but far less than was feared. Rather than originating in the Lower Barun glacial lake or as a result of heavy rains and flooded tributaries, as some surmised, the flood’s trigger appears to have been two surficial glacial lakes on the Langmale Glacier just east of the Langmale settlement area, most likely supplemented by englacial conduit and subglacial conduit, as in the Lhotse glacier flood Byers observed and recorded last June. The combined volume of water cascaded over the Langmale’s terminal moraine, creating a huge torrent that picked up more material and debris as it cascaded down the Barun River channel, carving out massive new river channels and flooding large areas of grazing and forest land. Regmi and Byers spoke with 16 villagers in Yangle Kharka, who said that they would be rebuilding them and returning home soon. The villagers expressed deep concern about the impacts of the flood on the coming tourist season. The damaged trails and bridges make it difficult for local porters and foreign trekkers to reach the region, and the dramatically changed landscapes, with landslide scars, are less visually appealing to tourists. McKinney, Regmi and Byers were only able to fly another 10 km or so down valley because of fuel shortages before returning to the upper Barun and Khumbu, but they noticed another very large and fresh torrent scar on the right bank of the Barun. They plan to study it as well and learn more about its possible role in...

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Flooding Glacial Lakes in Chile

Posted by on May 9, 2017 in Adaptation, All Posts, Featured Posts, Science | 0 comments

Flooding Glacial Lakes in Chile

Spread the News:ShareIt is a peaceful experience to walk near the glacial lake near Colonia Glacier, one of several prominent glacier lakes in Patagonia, Chile. The breeze on the lake helps you relax as you look out on the distant glaciers. In such a tranquil setting, it is hard to imagine that a glacial lake outburst flood (GLOFs) could pose a threat to the area. However, GLOFs have become a significant but poorly understood hazard of a warming global climate. The truth is, melting Colonia Glacier, located in the Northern Patagonian Ice Field, Chile, has caused dozens of GLOFs over the years. The lake near Colonia Glacier, Cachet II, has been drained frequently after unexpected floodings. The people living nearby are under constant threat of a sudden flood, which could completely destroy homes and livelihoods. Actually now, in the Chilean and Argentinean Andes, recent research by project member Pablo Iribarren Anacona has identified at least 31 glacial lakes have failed since the eighteenth century, producing over 100 GLOF events. “These lakes can be dangerous, and we need to take action,” Alton Byers, a geologist at the University of Colorado, told GlacierHub. A group of scientists concerned about GLOF risk have initiated a project, “Glacier Hazards in Chile,” which aims to answer key questions concerning past, present and future glacial hazards in Chile. One of the members is Ryan Wilson, a glaciologist at Aberystwyth University in the United Kingdom. “The project will assess the changing magnitude, frequency, and distribution of different glacial hazards in Chile under current and future global climate change,” Wilson explained to GlacierHub. At the moment, Wilson and the other researchers are focusing on understanding the processes that govern the development of GLOFs in Chile. The fieldwork of Wilson and his team was recently featured in Science. The them held a workshop at Aberystwyth University in July 2016, during which they discussed progress on their Chilean fieldwork, glacial lake mapping, glacial hazard assessment, outburst flood modeling and climate modeling. To assess GLOFs and GLOF risk, the team compiled a glacial lake inventory for the central and Patagonian Andes (1986 – 2016). Wilson said they used remote-sensing and fieldwork to find past GLOF sites around the major icefields, satellite glaciers and snow-and ice-capped volcanoes of Chile. “We have managed to use this lake inventory to inform field campaigns in February to two interesting glacial lake sites in Chile,” Wilson said. “We conducted aerial drone surveys and collected lake bathymetry data.” The team will next analyze flood hydrographs (a graph showing the rate of flow versus time past a specific point in a river) of selected former GLOFs and use these to establish the patterns of downstream impacts. They are proud of their work so far, which they hope to publish soon. Using the inventory across Chile, the team and local community  are able to assess the potential damage GLOFs can cause. Wilson et al. plan to “conduct numerical simulations of downstream impacts for selected potential GLOF sites using physically-based numerical flood models.” In collaboration with Chilean partners, this research will be used to develop early warning systems and raise awareness about quantified GLOF risks. Glacial hazards have threatened various commercial and governmental stakeholders across Chile, making GLOFs a pressing priority. The ultimate goal of the project is to provide a framework that can be applied to other lower income countries, since GLOFs pose threats in multiple countries. “We will make recommendations for GLOF hazard assessment protocols and mitigation strategies in lower income countries globally,” Wilson told GlacierHub. Spread the...

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Earthquake in Peru Creates Fear of Glacier Floods

Posted by on Mar 8, 2017 in All Posts, Communities, Featured Posts, News, Policy and Economics | 0 comments

Earthquake in Peru Creates Fear of Glacier Floods

Spread the News:ShareAn earthquake in Peru earlier this year produced significant ground shaking in highland regions of the country. It set off a wave of panic that glacial lakes in the Andes might burst their banks and create devastating floods. The quake, of magnitude 5.3 on the Richter scale, took place at 1:42am local time on January 28. As reported by the U.S. Geological Survey’s Earthquake Hazards Program, its epicenter was located under the Pacific Ocean, about 55 kilometers from the port of Chimbote in the region of Ancash, where the shaking was most instance. It was felt up and down the coast, as far north as Trujillo and as far south as Lima. The tremors also extended inland. This earthquake was the first of a cluster. The second occurred five hours later in the town of Ica to the south of Chimbote. The third took place two hours after that, near Arequipa, still further to the south. These were smaller—4.7 and 4.4, respectively—but close enough in time to create a stir in the media, with extensive coverage all day long in national media. Moreover, Peru had experienced mudslides and debris flows in the months before the earthquake, adding to the sense of concern. Sismo de 5,1 se registró este viernes en el sur de Perú https://t.co/tD3ANGnumU #Actualidad #Noticias — Noticias24 Carabobo (@N24_carabobo) January 28, 2017 The first earthquake was a source of great concern in the highland areas closest to Chimbote, particularly in the Callejón de Huaylas—the long valley along the Santa River, just below the Cordillera Blanca, the mountain chain which contains the largest area of glaciers in Peru. The regional capital of Huaraz and several other sizable towns are located in this valley, which has experienced a number of destructive glacier lake outburst floods. Christian Huggel, a Swiss glaciologist who was working in the area at the time, wrote, “We felt the earthquake here in Huaraz during the night.” He added, “I did not see any damage in the morning, so everything seems to be okay around here.” Benjamin Morales, the director of Peru’s National Institute for Research on Glaciers and Mountain Ecosystems, told GlacierHub that “the heavy rainfall and landslides in central and southern regions [of Peru]” added to the concern following the earthquakes, sensitizing the whole country to the risk of natural hazards even though risks were not as severe in Ancash and north of the country, where, he said, “rainfall is lower.” Tony Oliver-Smith, an anthropologist at the University of Florida with extensive experience in the region, indicated to GlacierHub that the timing of the events, in the middle of the rainy season, was significant. He wrote, “Those of us who have worked in the Callejon de Huaylas are always alert to the effects of earthquakes and landslides, particularly in the rainy season,” when soils are moist, and more likely to erode. The greatest fear was in Carhuaz, a provincial capital to the north of Huaraz. It lies near Huascaran, the tallest peak in the Cordillera Blanca, and the site of one of the world’s largest glacier lake outburst floods in 1970. This event, triggered by an earthquake, led to a debris flow which covered the town of Yungay, with about 6,000 fatalities. A series of smaller aftershocks which followed the main earthquake kept the tensions high in Carhuaz. A Peruvian newspaper, Primera Página, reported that people were concerned that “blocks of ice would detach from glaciers and fall into the lake.” The resulting waves could overtop the rock walls that rim the lake and create a flood. The residents of Carhuaz were also aware that the town...

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Flood Early Warning Systems Leave Women Vulnerable

Posted by on Feb 9, 2017 in All Posts, Communities, Featured Posts, Policy and Economics | 0 comments

Flood Early Warning Systems Leave Women Vulnerable

Spread the News:ShareGlacier lake outburst floods (GLOFs) pose an immediate threat to locations in mountain regions where rising temperatures contribute to glacier melt. This risk makes it crucial that communities at risk to GLOFs develop early warning systems (EWS) to alert residents of impending danger. In order for EWS to be effective, gender needs to be prioritized. In a recent paper published by the International Center for Integrated Mountain Development (ICIMOD), Mandira Shrestha et al. evaluated flood early warning systems in Bhutan and found that many EWS exclude women, who are especially susceptible to natural disasters like GLOFs. GLOFs, which are difficult to predict and devastating to local populations, occur when meltwater is suddenly released from a lake just below a glacier. When this occurs, large amounts of water rush down valleys, picking up debris. They can lead to many deaths and to extensive destruction of fields and property.   In total, Bhutan has 24 lakes which are capable of causing GLOFs.  As temperatures rise, glacier melt increases, leading to exposed moraines and larger volumes of water. However, an EWS can help save lives during a GLOF, especially if it is combined with preparatory actions before a flood occurs. In Bhutan, the EWS was first introduced in 1988 as part of the Hindu Kush Himalayan – Hydrological Cycle Observing System (HKH-HYCOS), a project developed by ICIMOD, national governments in the region, and the World Meteorological Organization. However, Shrestha et al. found that none of the current policies in Bhutan’s EWS address specific needs and experiences of women during natural disasters. In planning documents, women are described as victims, rather than presented as playing an important role in disaster risk management. The Bhutan EWS contains four major elements, also found in other warning systems: risk assessment, monitoring and warning, dissemination and communication, and response capability. The Bhutanese government first prioritized flood early warning systems in 1994, following a detrimental GLOF, which killed 12 people, destroyed 21 homes, and washed away nearly 2,000 acres of land. Shrestha et al. point out that even a good warning system would not be fully effective in preventing such a tragedy if it fails to reach vulnerable populations like women, as well as other such populations including children, disabled people, and the elderly. As Shrestha et al. explain, while women in Bhutan make up 49% of the population and legally have equal rights and access to education, public services, and health care, most women engage in household labor, while men dominate political work. The authors indicate that only 25 percent of women in Bhutan are involved in non-agricultural work. Extensive male out-migration in Bhutan, as elsewhere in the Hindu Kush Himalayas, leaves women to carry out the work in domestic agriculture. As a result, Bhutanese women are excluded from decision-making processes at community or larger scales. This pattern is reflected in other nearby countries as well.  One study done on disaster-affected people seeking mental health care in Bangladesh, which has the highest natural disaster mortality rate in the world, found that women have higher mortality rates in natural disasters, and are also extremely vulnerable in the aftermath of a natural disaster. For example, they are more likely to face food shortage, sexual harassment, and disease, among other issues. Shrestha et al. describe how the social structure in Bhutan leaves women dependent on men for receiving disaster information, because these details are shared in public places, where women typically do not go. Many of the alerts are done through sirens, but some women cannot hear them as they are located in towns rather than rural areas. Even if women do receive the information, it is...

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