Nepal is in the top 10 percent of countries in the world in terms of the frequency and severity of disasters. A recently published study in the journal Land has found that more than a quarter of the new houses in Pokhara, the second-largest city in Nepal, are being built in highly dangerous areas susceptible to multiple natural hazards, including glacier lake outburst floods (GLOFs) and avalanches.
The study lists a number of challenges for this rapidly-growing city, located in a region with a number of geological hazards. Most of the newly settled areas are located in agricultural areas. These are attractive to prospective residents, because they are flat and have owners who permit construction. However, these locations place new houses at great risk. The researchers indicate that this growth will continue until at least 2035.
Time-series Landsat images helped the researchers to explore the changes in land use and urbanization of the Pokhara from 1988 to 2016. The images were verified using extensive field visits to ensure accuracy. They served as a basis for projections into 2025 and 2035.
GLOFs are a major threat in Nepal, where 15 percent of the country is covered by the Himalayan mountains. This holds true for the Kaski District, where Pokhara is located. With rapid melting due to rising temperatures, glacier lakes are forming and increasing the level of risk seen in the surrounding areas.
Two of the most prominent issues in dealing with hazards such as this in Pokhara are uncertainty and perception. According to a report by the International Centre for Integrated Mountain Development (ICIMOD), “The probability of a lake outburst cannot be predicted with any reasonable level of certainty.” In addition, the views of the people at greatest risk are often more strongly influenced by, often inaccurate, media accounts than by scientific assessments.
Tony Oliver-Smith, a Professor Emeritus of Anthropology at the University of Florida, told GlacierHub about his work in hazard perception and resettling. “Some people may be generally aware of the risks, but the need for housing is so great that it may override such concerns,” he said. This kind of drive is typical for areas like this one that are undergoing rapid urbanization, often in unplanned environments. “Many people prefer to take their chances with hazards rather than government schemes to relocate them in more secure zones,” continued Oliver-Smith.
Further, cities like Pokhara often lack relevant legislation and regulatory capacity, appropriate agencies, and personnel both in qualifications and number, to enforce land use restrictions regarding housing location and safety, according to Oliver-Smith. A practical application of the study’s findings, he said, would be to develop appropriate legislation and funding to improve land use regulatory capacity, increase awareness of risk in vulnerable and exposed communities, and develop appropriate legislation and capacities in resettlement practice.
Natural hazards are on the rise globally, and with more people moving to more susceptible areas, the losses in human life and property are likely to increase. “As you put more and more people in harm’s way, you make a disaster out of something that before was just a natural event,” Klaus Jacob, a senior research scientist at Columbia University’s Lamont-Doherty Earth Observatory, told Live Science. To make matters more difficult, the study emphasizes that “developing countries with low-income and lower-middle economies experience greater loss and damage due to hazards.”
The researchers hope that their results “will assist future researchers and planners in developing sustainable expansion policies that may ensure disaster-resilient sustainable urban development of the study area.”
The study ultimately illuminates the common risk of hazards that people all over the world face. Luxury apartments being built along coastlines in flood-prone cities threatened by sea level rise continue to be built, similar to the continued urbanization in Pokhara. It’s a common situation, and finding solutions requires place-based, locally-specific information and research.
A longer version of this post appeared in the April 2017 issue of EcoAmericas.
When a flood from a mountain lake threatened to swamp the town of Carhuaz in the Peruvian Andes early one morning in April 2010, Víctor Rodríguez was the only person who knew. From his hut on a plain below the mountain, he heard the jet-like rumble as a block of ice calved off a glacier and crashed into the lake. The force of the fall produced a wave that swept over the earthen dike around the water body, called Lake 513, and cascaded down the steep slope. Rodríguez watched as the water swirled across the plain, swamping the catchment for the municipal water system, where he worked as caretaker. Picking up speed as it funneled into the Chucchún River, the torrent of water carrying mud and boulders swept away crops, livestock and some buildings. But it stopped just short of the town of about 12,000 people beside the Santa River, at the foot of Peru’s Cordillera Blanca.
The Destruction of an Early-Warning System
With climate change increasing the threat of such hazards, the Swiss government’s development agency, a Peruvian nonprofit, and a Swiss university teamed up to develop a high-tech early-warning system. By the end of 2013, lakeside sensors and cameras were in place above Carhuaz, with relay antennae that could transmit information quickly to a command center in the municipal offices. Once its kinks were worked out, the organizers of the project hoped the system could serve as a model for other towns that lie below glacial lakes. Then disaster struck again, this time in the form of a drought. Not only was rain scarce, but an unseasonable frost damaged crops. Rumors spread among residents of the farming communities around Carhuaz that the monitoring equipment at Lake 513 was preventing clouds from forming. Early one morning last November, several hundred people from the largely indigenous communities, where traditional Andean beliefs still hold sway, trekked up to the lake and tore down the system. Within a week, it rained.
The events raise questions about how to ensure that in areas where rural residents distrust technology, systems can be created to reliably warn those in the path of Carhuaz-style deluges, known as glacial lake outburst floods, or GLOFs. It also highlights tensions between growing urban areas and their rural neighbors— tensions that could deepen as dense development encroaches on agricultural land and city dwellers demand a larger share of water from threatened sources.
The destruction of the Carhuaz early-warning equipment came as a shock to the system’s developers, but in hindsight, signs of discontent had been building. During workshops in 2012, residents said they felt unprotected against outburst floods like the one in 2010, says Karen Price Ríos of CARE Peru, a nonprofit development organization that has been active in the area for several years. Price worked with local communities on the three-year early warning project, which was funded by the Swiss aid agency COSUDE and supported by researchers from the University of Zurich. The researchers drew up a risk map, showing the areas in varying degrees of danger from a mudslide like that of 2010, and devised evacuation routes, marking them with signs. The centerpiece of the project was the early-warning system on Mount Hualcán. If a block of ice broke from the glacier and crashed into Lake 513, it would trigger sensors that would turn on cameras and send an alert to local officials. They could then check the images from the cameras to verify the flood and sound an alarm.
The early warning would give local residents about half an hour to evacuate to safety zones. One monitoring station was installed at Lake 513, some 4,491 meters above sea level, with additional equipment several hundred meters higher. A repeater down in the valley boosted the signal before it reached the municipal offices in Carhuaz, at 2,641 meters above sea level. Another monitoring station— on the plain below Mount Hualcán, beside the upper part of a system of irrigation canals and the intake for Carhuaz’s drinking water system— gathered water-level and flow data from the Chucchún River.
The system was installed in 2012. In 2015, CARE’s Glacier Project in Carhuaz officially ended and the system was turned over to the Carhuaz provincial government headed by Mayor Jesús Caballero García, who had taken office in January. Though the head of the local disaster management office could monitor the system, the government lacked funds for specialized maintenance, Caballero says. “We didn’t have personnel trained to evaluate the entire system and say whether it was functioning,” he says.
In 2016, lack of rain became a more pressing concern than an outburst flood for farmers in the rural communities along the Santa River and its tributaries, including the Chucchún. It is not clear when people began to blame the equipment on Mount Hualcán, but in February 2016, one local leader asked Caballero to remove it. Two months later, vandals stole the cameras from the lakeside monitoring station. It might have been an ordinary theft, but observers note that it would be difficult to fence the specialized cameras in local black markets.
CARE and COSUDE agreed to replace the stolen cameras, but before arrangements could be made, leaders from several surrounding communities again demanded that the equipment be removed. A town hall-style meeting was scheduled for November to discuss the problem, but on Nov. 24, several hundred people from surrounding communities marched up the mountain to the lake. Caballero says he accompanied the group to persuade the protesters to leave the equipment in place, but after a few tense hours, they tore down what was left of the equipment beside the lake and the monitoring station on the plain below.
The Search for an Explanation
A few months later, some embarrassment seemed to have set in. It is difficult to find people who will admit to dismantling the equipment, although some will talk about the beliefs that led to the action— that the equipment “blew the clouds away,” or that it might have been placed there to benefit some outside interest, such as a mining company. It was not the first time equipment had been blamed for unfavorable weather near Carhuaz. Nearly two decades ago, farmers demanded that another researcher remove meteorological monitoring devices from the mountain. “People have a very close relationship with the mountains,” says geographer Christian Huggel of the University of Zurich. “The snow-capped peaks are living beings.”
With time, however, a more complex picture of the tensions over the Carhuaz early-warning system have emerged. In workshops with Glacier Project staff shortly after the 2010 outburst flood, people in both Carhuaz and the surrounding farming communities identified floods as the greatest natural hazard they faced. Climate change, it seemed, was on everyone’s mind. And in a study conducted during 2012-14, sociologist Luis Vicuña found that when discussing risks, people in the farming communities around Carhuaz spoke of climate change in virtually the same terms they had heard in the workshops. But when Vicuña changed the question slightly, he found that farmers were actually more concerned about their supply of irrigation water—whether they would continue to have enough water, and how much of a say they would have in managing it.
The water worries reflected tensions between the farming communities and the town of Carhuaz, where population growth has pushed the urban limits farther into the countryside. Farms have been shrinking as demand for food has been increasing, Vicuña says. The expanding urban population has increased demand for drinking water, too, says Lindón Mejía, who manages the city’s water and sanitation system. Since the timing of the Glacier Project happened to coincide with plans to expand Carhuaz’s potable water system, the drought may have exacerbated fears of more water being used for the urban area.
At the heart of those fears is concern that less irrigation water will be available for rural residents, who in addition face a lower risk of outburst-flood damage than town dwellers since they live on higher ground. Such tensions, combined with local urban and rural political dynamics, probably created fertile ground for rumors that led the crowd to tear down the monitoring stations, Vicuña says. Glacier Project staff made a concerted effort to forge consensus, meeting with people in the urban area and in the villages closest to Carhuaz. But many of those who climbed the mountain to pull down the monitoring equipment were from villages outside the area that would be in the path of an outburst flood from Lake 513. They knew little about the system and did not stand to benefit from it, Vicuña says. CARE and COSUDE decided not to reinstall the system at Lake 513, although COSUDE will finance a similar system around Santa Teresa, in the southern Peruvian region of Cusco.
Meanwhile, researchers, project staff and government officials puzzle over what could be done differently next time. Any such project, whether in Huaraz or elsewhere, should involve more extensive studies of local communities and political positions, Vicuña says. Another possibility might be to turn local residents into citizen scientists. Anthropologist Ben Orlove of Columbia University says the citizen scientists might be invited to help gather data and become part of the study, rather than simply witnessing the installation of instruments they don’t understand. And when new local government officials take office, attention must be paid to ensure that they will take responsibility for early-warning systems installed by their predecessors, says Martin Jaggi, COSUDE’s director of global cooperation programs.
The question will only become more critical. The Andes Mountains are home to the largest expanse of tropical glaciers in the world, but the ice fields have been shrinking significantly over the past half-century. A warmer climate means glaciers will continue to recede, and their meltwater will feed lakes high above valley towns. This, in turn, will heighten the risk of outburst floods.
Despite the dismantling of its early-warning equipment, Carhuaz is nevertheless better protected than it was before, Huggel says. Government officials and residents are more aware of the outburst-flood risks, evacuation routes are clear, and the personnel who keep watch over the city’s drinking water intake 24 hours a day can radio a message to the town in case of a flood. It is estimated that town residents can expect warnings 10 to 15 minutes before outburst waters arrive. That’s significantly less time to evacuate than the 30 minutes promised under the high-tech system originally envisioned, but the current plan still could be efficient, Huggel says. He adds: “The early warning system is much more than just instruments.”
From The Cryosphere: “Glacier outburst floods with origins from Lhotse Glacier, located in the Everest region of Nepal, occurred on 25 May 2015 and 12 June 2016. The most recent event was witnessed by investigators, which provided unique insights into the magnitude, source, and triggering mechanism of the flood. The field assessment and satellite imagery analysis following the event revealed that most of the flood water was stored englacially and that the flood was likely triggered by dam failure.”
From Nature: “Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs. Here we show that surface runoff from three island groups of the maritime Antarctic exports more filterable than icebergs. Glacier-fed streams also export more acid-soluble iron associated with suspended sediment than icebergs. Significant fluxes of filterable and sediment-derived iron are therefore likely to be delivered by runoff from the Antarctic continent. Although estuarine removal processes will greatly reduce their availability to coastal ecosystems, our results clearly indicate that riverine iron fluxes need to be accounted for as the volume of Antarctic melt increases in response to 21st century climate change.”
From International Soil and Water Conservation Research: “One fifth of the world’s population is living in mountains or in their surrounding areas. This anthropogenic pressure continues to grow with the increasing number of settlements, especially in areas connected to touristic activities, such as the Italian Alps. The process of soil formation on high mountains is particularly slow and these soils are particularly vulnerable to soil degradation. In alpine regions, extreme meteorological events are increasingly frequent due to climate change, speeding up the process of soil degradation and increasing the number of severe erosion processes, shallow landslides and debris flows. Vegetation cover plays a crucial role in the stabilization of mountain soils thereby reducing the risk of natural hazards effecting downslope areas.”
Uttarakhand Himalaya in northwest India is a rural, mountain region that shares borders with Nepal and Tibet. Often referred to as “The Land of Gods” for its physical grandeur, Uttarakhand is surrounded by some of the world’s highest peaks and glaciers. However, such beauty comes at a price. The Uttarakhand area is prone to natural and glacier-related disasters, often exacerbated by the region’s topography and climate patterns. Landslides, triggered by heavy rainfall and events called glacial lake outburst floods (GLOFs), expose the high mountain communities to infrastructure, life and community losses. A recent article by Naresh Rana Poonam et al. in Geomorphology measured and mapped susceptibility in Uttarakhand to help create a template that can be applied to locations facing similar climate-related landslides.
To conduct their research, Poonam et al. relied on Landslide Susceptibility Zonation (LSZ) mapping in order to deepen understanding and response in Uttarakhand to local hazards in a manner that can also be replicated elsewhere. Landslide Susceptibility Zonation (LSZ) is a type of mapping system that organizes different variables like geological, geomorphic, meteorological and man-made factors as high-risk based on the chances of slope failure. A slope failure occurs whenever a mountain slope collapses due to gravitational stresses, often triggering a destructive local landslide. Mapping these vulnerabilities is critical to understanding the dynamics and potential force of future landslides in the Himalayas and elsewhere.
Many of Uttarakhand’s peaks have year-round snowpack with glaciers and glacial lakes that can be disturbed by shifting rainfall patterns and changes in the onset of monsoon season. These disruptions can cause a destabilization deep within the ground, causing the initial movement needed to produce a landslide. Additionally, Uttarakhand’s proximity to the Indian Plate, a large tectonic plate where movement occurs along the boundaries, makes it especially vulnerable to frequent earthquakes. According to the United States Geological Survey, the last earthquake in Uttarakhand occurred on December 1, 2016, with a 5.2 magnitude. The energy released during an earthquake of that magnitude has the potential to trigger multiple, large-scale landslides.
Given the high-altitude location of Uttarakhand, earthquakes can also cause glacial lake outburst floods (GLOFs), a type of flood that occurs when the terminal moraine dam located at the maximum edge of a glacier collapses, releasing a large volume of water. These events can be especially destructive to rural mountain communities that are hard to access, making recovery efforts challenging and untimely. Additionally, these villages are often settled in areas where landslides naturally funnel. Preparing mountain communities to understand the risks they face is critical to minimizing damage associated with natural disasters. As a recent article in GlacierHub points out, “Educating and adapting ensures resilience to risks associated not only with glacial outburst flood risks, but also other risks associated with changing climates.” In an attempt to lower the risk of a landslide disaster triggered by a glacial lake outburst flood or rainfall event, Poonam et al. looked at ways to increase accuracy of floodplain mapping. The hope is to help increase the resiliency of communities by encouraging smart expansion with higher predictability of slide prone areas.
LSZ mapping is created using the Weights of Evidence method, a statistical procedure for calculating risk assessment using training data, like an established inventory of previous landslides. This statistical approach allows for information retrieved from a geographic information system (GIS) and remotely sensed data to be integrated regionally. LSV maps can also be derived from a knowledge-driven method that involves more human interpretation; however, this method is based on expert evaluations of a location. According to the article, the statistical approach is used more frequently because it lacks the subjective nature of the knowledge-driven method. When a location is evaluated by an expert, risks and interpretation of potential risks will differ based on the expert, leaving the risk of human error. The statistical approach provides consistency and confidence of regional LSZ maps because they can be interpreted using a common baseline.
The researchers hope that more precise mapping will help communities prepare for disasters such as the one that occurred in Uttarakhand in 2013. In a normal year, the monsoon rains soak Uttarakhand during the second week of July; however, in 2013, those rains arrived in June, a month earlier than expected, catching Uttarakhand off guard. During the spring months, water levels are high with snowmelt from rivers and glacial lakes. Combining monsoon rains with snowmelt during the spring can lead to devastating floods and landslides. As a result, 7,000 people and hundreds of animals lost their lives in a rainfall event on June 15th that took place in the Mandakini Valley, east of Nanda Devi National Park, according to BBC News. Adding to the devastating losses, the Manadkini Valley is also home to the Kedarnath Temple, where Hindu pilgrims travel between the months of May to October. The high volumes of people paired with the early-activated monsoon resulted in increased losses.
After experiencing the devastation of the landslides resulting from the June 2013 monsoon, many people thought the risk of staying in Uttarakhand was too high, so they relocated to the plains. The outmigration left 3,600 villages mostly deserted, as reported by Poonam et al. Outmigration due to climate-related disasters places mountain communities at additional risk for economic stagnation that may lead to increased forced migration to other areas.
Educating communities in both a scientific and social capacity on the risks associated with the natural interaction of weather and a geography allows for increased awareness among local populations which can help lead to better preparedness for future events. According to a recent GlacierHub article, the state of Jammu and Kashmir, located nearby, held a workshop to communicate risk to small mountain communities to help them understand and raise awareness into the unique risks associated with their location. Like with Uttarakhand, it’s not a question of if these events will happen, but when. Providing communities with detailed maps highlighting certain areas that are more prone to landslides and GLOFs will not eliminate the risk, but it may lower it. Combining LSV mapping with education programs on how to use the mapping information will provide small mountain villages with the future tools to build more sustainable and resilient communities. Since LSV mapping efforts are still being integrated, success may not be immediate. However, LSV mapping shows tremendous potential to enable people to continue residing in the world’s richly historic and picturesque locations.