No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Climate Change Induced Glacier Retreat and Risk Management: Glacial Lake Outburst Floods (GLOFs) in the Apolobamba Mountain Range, Bolivia
Abstract
Due to global warming, tropical glaciers in the Bolivian Andes have lost about half of their volume and surface area since 1975. Throughout the Apolobamba mountain range, the retreat of glaciers has resulted in the formation of small and medium-sized lakes on the glacier terminus. Many of the glacial lakes are contained only by loose moraine debris: thus they can pose a significant threat to human settlements and infrastructure downstream. Considering the fact that the Cordillera de Apolobamba holds the largest continuous glaciated area in Bolivia, which measured 220 km² in the 1980s, there is a legitimate concern regarding the dangers that might affect this mountain region. Yet there is no documentation available on glacial lakes in the Apolobamba mountain range; indeed there is little awareness of the related risks. Only recently has glacial retreat, and climate change impacts in general, been given some importance in the planning and management of the Apolobamba National Protected Area for Integrated Management, thereby opening a discussion on natural hazard threats and the development of adaptation strategies with the objective of minimising risks for human populations and local infrastructure. This paper presents documentation of glacier retreat and the forming of glacial lakes in the Cordillera of Apolobamba over the last 35 years. In addition, the risk potential of glacial lake outburst floods and the risk awareness of the local population will be analysed in relation to park management options, and ideas outlined for more detailed studies of glacial lake outburst floods in Bolivia.
... Like glaciers in many other mountains around the world, the Andean glaciers are generally in recession since the Little Ice Age (LIA) (Rabatel et al., 2013). It has been suggested that the current warming of the climate and related enhanced glacier melting resulted in the expansion or formation of numerous glacial lakes throughout the Andes (e.g., Veettil and Kamp, 2019;Veettil et al., 2017a, b;Cook et al., 2016;Hoffmann and Weggenmann, 2013;Rabatel et al., 2013;Carey, 2005). This is alarming since it is believed that until the end of 21st century the atmospheric warming rate in mountainous regions should be higher than that in lowlands (Pepin et al., 2015;Bradley et al., 2006Bradley et al., , 2004. ...
... In recent decades, numerous glacial lakes have formed across the tropical Andes (Veettil et al., 2017a;Cook et al., 2016;Hoffmann and Weggenmann, 2013), and their formation and expansion have been interpreted as a direct result of the rapid decline of glaciers since the late 1970s (Veettil et al., 2017b;Vuille et al., 2017). Compared to other tropical regions, Peru and Bolivia have the largest glacier coverage (Vuille et al., 2008) and, potentially, number of glacial lakes that need to be monitored. ...
... The expansion and formation of glacial lakes pose a threat to local communities. In the Cordillera Apolobamba, in November 2009, the Keara GLOF happened after the breach of the ice dam resulting in the loss of cattle and the destruction of some infrastructure; fortunately, no human causalities were claimed (Hoffmann and Weggenmann, 2013) (Fig. 4). An assessment of glacial lakes in the eastern part of the country concluded that GLOF hazard across Bolivia does not receive the needed attention from the scientific community (Cook et al., 2016). ...
In this article, we review the current knowledge of the glacial recession and related glacial lake development in the Andes of South America. Since the mid-1980s, hundreds of glacial lakes either expanded or formed, and predictions show that additional hundreds of lakes will form throughout the 21st century. However, studies on glacial lakes in the Andes are still relatively rare. Many glacial lakes pose a potential hazard to local communities, but glacial lake outburst floods (GLOFs) are understudied. We provide an overview on hazards from glacial lakes such as GLOFs and water pollution, and their monitoring approaches. In real-time monitoring, the use of unmanned aerial systems (UASs) and early warning systems (EWSs) is still extremely rare in the Andes, but increasingly authorities plan to install mitigation systems to reduce glacial lake risk and protect local communities. In support, we propose an international remote sensing-based observation initiative following the model of, for example, the Global Land Ice Measurements from Space (GLIMS) one, with the headquarters in one of the Andean nations.
... GLOF risk in Bolivia has received very little attention despite an event having occurred here in 2009, when an ice-dammed lake drained catastrophically, impacting the village of Keara in the Cordillera Apolobamba (Hoffmann and Weggenmann 2013). Recent work by Cook et al. (2016) found that glacier area in the Bolivian Andes had reduced by ~ 43% from 1986 to 2014, leading to an increase in the number and areal coverage of proglacial lakes. ...
... The Keara GLOF took place on 3 November 2009 at about 11:00 a.m. local time and involved the complete drainage of an ice-dammed lake (Hoffmann and Weggenmann 2013). This event flooded cultivated fields, destroyed several kilometres of a local dirt road, washed away pedestrian bridges, and killed a number of farm animals (Hoffmann and Weggenmann 2013). ...
... local time and involved the complete drainage of an ice-dammed lake (Hoffmann and Weggenmann 2013). This event flooded cultivated fields, destroyed several kilometres of a local dirt road, washed away pedestrian bridges, and killed a number of farm animals (Hoffmann and Weggenmann 2013). Fortunately, there were no human fatalities. ...
The Bolivian Andes have experienced sustained and widespread glacier mass loss in recent decades. Glacier recession has been accompanied by the development of proglacial lakes, which pose a glacial lake outburst flood (GLOF) risk to downstream communities and infrastructure. Previous research has identified three potentially dangerous glacial lakes in the Bolivian Andes, but no attempt has yet been made to model GLOF inundation downstream from these lakes. We generated 2 m resolution DEMs from stereo and tri-stereo SPOT 6/7 satellite images to drive a hydrodynamic model of GLOF flow (HEC-RAS 5.0.3). The model was tested against field observations of a 2009 GLOF from Keara, in the Cordillera Apolobamba, and was shown to reproduce realistic flood depths and inundation. The model was then used to model GLOFs from Pelechuco lake (Cordillera Apolobamba), and Laguna Arkhata and Laguna Glaciar (Cordillera Real). In total, six villages could be affected by GLOFs if all three lakes burst. For sensitivity analysis, we ran the model for three scenarios (pessimistic, intermediate, optimistic), which give a range of ~1100 to ~2200 people affected by flooding; between ~800 and ~2100 people could be exposed to floods with a flow depth ≥2 m, which could be life threatening and cause significant damage to infrastructure. We suggest that Laguna Arkhata and Pelechuco lake represent the greatest risk due to the higher numbers of people who live in the potential flow paths, and hence these two glacial lakes should be a priority for risk managers.
... In Peru in 1941, an outpouring destroyed the village of Huaraz affecting 5000 people (Carey, 2010). In Bolivia, the risk of disaster related to glacial shrinkage is lower, but, according to Hoffmann and Weggenmann (2012), there is still concern with the danger of GLOFs in certain parts of the country. In 2009, a glacial lake above a small village in Apolobamba's Cordillera sent a wave of water downstream, flooding cultivated fields, destroying local roads, and killing some domestic animals. ...
... In Ecuador, the glacier Cotacachi completely melted over the past decade, considerably affecting agriculture and the local tourism sector (Rhoades, 2008;Rhoades et al., 2006). Finally, authors studying GLOF risk suggest that relocation is an option to avoid disasters for parts of exposed villages (Hoffmann & Weggenmann, 2012). ...
... Une autre spécificité liée à la dimension des glaciers concerne l'exposition aux risques de GLOF's. Le risque est pratiquement inexistant en Bolivie (Hoffmann & Weggenmann, 2012), alors qu'au Pérou des événements de ce type ont donné lieu à des tragédies de grande ampleur (Carey, 2010). Cette réflexion s'applique également pour le cas des régions montagneuses de l'Himalaya où la gestion des lacs de haute montagne représente un enjeu majeur pour la sécurité des populations vivant en aval de ces réservoirs (Botez, 2010). ...
Cette thèse a pour objectif de questionner, par l’intermédiaire d’une étude de cas dans les Andes boliviennes, le rôle des effets du changement climatique et plus largement des dégradations environnementales sur les migrations de populations. L’étude est articulée autour de quatre articles scientifiques et du texte cadre qui explicite l’ensemble du projet de recherche.
Mon analyse exhaustive des études empiriques portant sur les conséquences migratoires du changement climatique ou des catastrophes environnementales en Amérique du Sud permet de relever le nombre encore modeste de ces études et leur répartition très inégale. On trouve en effet beaucoup plus d’enquêtes sur l’Amérique centrale et en particulier sur le Mexique. En revanche, les pays andins restent peu explorés malgré leur forte vulnérabilité environnementale. Une des conclusions centrales du travail est que la relation entre les changements environnementaux et les migrations observée en Amérique latine confirme les principales tendances soulignées dans d’autres régions du monde : les déplacements se font le plus souvent sur de courtes distances avec une forte attraction des centres urbains. Dans le cas de catastrophes soudaines, les déplacements sont souvent de courtes durées. Il ressort également de l’étude que certains effets du changement climatique sur les migrations concernent tout particulièrement l’Amérique latine. C’est le cas de la fonte des glaciers tropicaux, dont les conséquences sur les sociétés sont encore peu étudiées. Le retrait glaciaire fait justement l’objet d’analyses approfondies dans cette étude.
Ma recherche identifie les principaux facteurs migratoires ainsi que les dynamiques migratoires à travers une étude de cas dans les régions montagneuses proches de La Paz en Bolivie. Des événements climatiques extrêmes, comme la grêle, le gel ou la forte variabilité de la disponibilité en eau pour l’irrigation, sont les principaux motifs environnementaux invoqués par les migrants. Ma recherche confirme donc le caractère multi-causal des migrations, où les facteurs environnementaux se combinent à d’autres facteurs migratoires comme l’accès aux terrains cultivables, à des emplois rémunérés ou à une formation supérieure. Les migrations observées sont régionales et se manifestent dans un contexte de relations migratoires préexistantes entre régions rurales et urbaines (La Paz et de El Alto), où l’on observe des mouvements d’allers-retours, de séjours temporaires ou encore de multi-résidences.
L’analyse approfondit également le rôle spécifique du retrait glaciaire au sein de ces dynamiques migratoires andines. Le retrait glaciaire est sûrement l’impact le plus tangible du changement climatique dans les Andes et plusieurs articles parus dans certains médias, rapports gouvernementaux ou d’ONG font état de potentielles conséquences migratoires. Cependant, mes résultats montrent qu’actuellement en Bolivie, le retrait des glaciers ne contribue pas à générer de nouveaux flux migratoires. En revanche, la fonte des glaces reste un phénomène préoccupant, car si elle ne pousse pas directement les gens à partir, la saisonnalité de la disponibilité en eau ou encore la dimension symbolique de la disparition de glaciers interfère néanmoins avec certains choix migratoires. Il génère par exemple, des craintes auprès des agriculteurs de montagnes quant aux possibilités futures de cultiver les terres dans des régions fortement dépendantes de l’eau des glaciers.
Mon étude se termine en questionnant les mécanismes qui ont fait de Khapi, l’un des quatre villages étudiés, le village le plus médiatisé de Bolivie lorsque sont évoquées les thématiques du retrait glaciaire et des « migrants climatiques ». Cette analyse permet de mettre en évidence le rôle et les agendas d’acteurs impliqués dans ce processus de médiatisation (journalistes, membres d’ONG, experts et habitants de la région). En donnant la parole aux habitants qui s’approprient, transforment ou rejettent les discours les concernant, mon étude permet d’aller au-delà de l’image simplificatrice et misérabiliste que l’on affecte souvent à ces « victimes-témoins ». Cette discussion contribue ainsi aux réflexions critiques sur la manière dont certaines régions du monde deviennent des études de cas emblématiques.
Finalement, mon étude apporte de nouveaux éléments de compréhension qui permettent de discuter de manière nuancée des impacts migratoires, des changements environnementaux et des enjeux de cette relation dans la région encore peu étudiée des Andes boliviennes. Sur la base de mon analyse, je propose, dans le chapitre conclusif, plusieurs pistes de recherches pour approfondir cette thématique ainsi qu’une réflexion sur les implications de cette recherche en termes de recommandations politiques.
... Unfortunately, several of these environmental factors show synergies with each other, and while our general knowledge of them has advanced (Williamson et al. 2019, Cabrerizo et al. 2020, Loria et al. 2020, it is still insufficient, mostly in the mountainous tropical belt. Regions near the Earth's equator reveal a stronger and earlier impact on temperature rise compared to temperate regions (Urrutia andVuille 2009, Hoffmann andWeggenmann 2013), and in the future, Latin America's mountainous ecosystems are expected to be warmer and drier climates than they are today. These changes may reduce water saturation in soils near waterbodies, preventing the flow of carbon from soil to waterbodies (e.g., lakes), reducing the attenuation of ultraviolet radiation (UVR) in the water column Zagarese 2003, Cooke andWilliamson 2006). ...
... Furthermore, other environmental factors such as predation (Alcocer et al. 2020, Oliver et al. 2022) come into play and can be more pressing than high elevation or UVR (Alcocer et al. 2020, Symons et al. 2021, setting the zooplankton assemblage in the position of choosing between pigmentation and becoming more conspicuous to predation. According to our results, when faced with climate change that predicts an increase in temperature (Urrutia andVuille 2009, Hoffmann andWeggenmann 2013) and greater penetration of UVR as an indirect effect Zagarese 2003, Cooke andWilliamson 2006), populations of D. pulicaria will likely collapse faster unless other global change factors (e.g., browning; Pilla and Williamson 2023) come into play. While our results suggest that Andean D. pulicaria populations are adapted to UVR exposure, the sheer number of possible interactions between environmental factors (Cabrerizo et al. 2020, Nevalainen et al. 2020) and community interactions complicates predicting the direct and indirect effects of temperature and UVR on zooplankton communities. ...
Aquatic organisms from high mountain lakes experience extreme influences of climate and solar radiation, especially ultraviolet radiation (UVR), manifested through alterations in physiology, life history, and phenology. Zooplankton, a pivotal component of lake ecosystems, is particularly sensitive to changes in environmental conditions because of their short life cycles and diminished mobility. In the high mountains of the tropical Andes, zooplankton populations are adapted to low temperatures and high UVR because most of the Andean lakes are >4000 m a.s.l. This study focuses on Daphnia pulicaria populations originating from high-mountain Andean lakes, investigating their responses to different temperatures and UVR exposure by means of lab experiments. Key findings indicate that temperature is the most important factor impacting population variables, with high temperatures and UVR exposure leading to unfavorable population outcomes; however, physiological variables (cell viability and pigmentation, measured as melanin) are similarly influenced by temperature and UVR exposure. Pigmentation increases with temperature and is accentuated by solar radiation, indicating an adaptive response to mitigate UVR damage. Conversely, cellular viability declines with elevated temperatures and UVR exposure, showing that higher temperatures may offset the protective effects of pigmentation. Overall, these findings underscore the vulnerability of daphnid populations in high-mountain Andean systems to anticipated climate change impacts, with potential consequences for ecological dynamics in these critical ecosystems. More importantly, they show the importance of studying temperature and UVR (and probably other environmental conditions) as interacting variables because the results will dramatically differ if each factor is considered separately.
... A nivel global, los desastres naturales de origen glaciar y especialmente los GLOFs han originado eventos catastróficos con importantes pérdidas humanas y materiales (Haeberli et al., 2013;Hoffmann y Weggenmann, 2013;Worni, Huggel y Stoffel, 2012;Booth y Punt, 2012;Jain et al., 2012;Mergili et al., 2012;Bajracharya y Mool, 2009;Harrison et al., 2006). En los Andes del Perú se han registrado repetitivos eventos GLOF en las últimas décadas con consecuencias en algunos casos devastadoras (Carey, 2010;Portocarrero, 2014). ...
... Además, para poder comprender en más detalle cambios en los factores climáticos a largo plazo y su posible impacto en la morfología (peri)glaciar, el desarrollo de las lagunas glaciares y cambios en las condiciones de amenaza, se debe contar con una mayor red de monitoreo meteorológica, glaciar y geomorfológica. Actualmente, no existe una red de monitoreo glaciar y sísmico sistemático ni en la Cordillera de Vilcabamba, ni en otras cordilleras vecinas (Hoffmann y Weggenmann, 2013). ...
En las últimas décadas, los glaciares de diferentes regiones montañosas han experimentado un retroceso sin precedentes desde finales de la Pequeña Edad de Hielo (LIA). Este proceso contribuye a la formación y crecimiento de lagunas glaciares, que en conjunto con otros componentes de potencial amenaza pueden generar condiciones más frecuentes y aptas para la ocurrencia de un desastre, como flujos por el desborde violento de una laguna glaciar (GLOFs). En los Andes del Perú, varios GLOFs han cobrado un gran número de pérdidas humanas y materiales, pero la colección de datos y la implementación de programas de monitoreo basados en la amenaza son escasos. Este estudio se centra en cambios de superficies lagunares y glaciares en la poco estudiada Cordillera de Vilcabamba (Cusco y Apurímac, Perú). Presentamos un marco multitemporal y semiautomatizado basado en el Índice Normalizado Diferencial del Agua (NDWI) y el Índice Normalizado Diferencial de la Nieve (NDSI) usando imágenes Landsat TM 5 y OLI 8 en el periodo 1991-2014. Nuestros resultados indican un fuerte retroceso del área glaciar de 51% entre 1991 (201.0 km2) y 2014 (98.9 km2). En el mismo período, el número de lagunas (superficie lagunar total) se ha incrementado de 247 (4.1 km2) en 1991 a 329 (5.2 km2) en el año 2014 lo cual corresponde a un crecimiento acelerado de 0.8% (0.6%) de 1991 a 2001 y 2.3% (1.7%) de 2010 a 2014, respectivamente. El mayor crecimiento de lagunas se ha identificado en áreas de altitud elevada (4400-4800 msnm) particularmente durante el último período (2010-2014) lo cual podría ser correlacionado a la desglaciación actual y, por ende, a cambios en características geomorfológicas. La discriminación de lagunas y el análisis de potencial amenaza se llevaron a cabo en un protocolo de cuatro etapas, en primer lugar, basado en las variaciones 2 superficiales de lagunas y la posible exposición de centros poblados ante un GLOF aguas abajo. Se aplicó criterios adicionales incluyendo (a) distancia glaciar-laguna, (b) tipo de dique, (c) período de formación, (d) pendientes críticas y (e) estimaciones de volumen. Un total de 52 “lagunas indicadores” han sido identificadas, de las cuales 13 lagunas glaciares están en contacto con 15 centros poblados expuestos aguas abajo. Dos de estas lagunas han sido clasificadas en un nivel de potencial amenaza bajomediano y tres en un nivel mediano-alto. Nuestros resultados tienen diferentes implicancias para la investigación y gestión del agua futuras. El continuo derretimiento glaciar y desarrollo de lagunas generan condiciones potenciales de amenaza y riesgo. Sin embargo, emergen oportunidades para una futura gestión (integrada) del agua considerando la necesidad de nuevos reservorios, p. ej., para la demanda de agua creciente de agricultura e hidroenergía en la región. La metodología presentada facilita un análisis efectivo y extenso de amenaza que debería ser corroborado también con data in situ y criterios adicionales aplicados a otras cordilleras glaciares. Futuros estudios deberían enfocarse en un mayor desarrollo de un análisis detallado, continuo y estandarizado de amenaza y riesgo, y monitoreo de lagunas glaciares.
... A nivel global, los desastres naturales de origen glaciar y especialmente los GLOFs han originado eventos catastróficos con importantes pérdidas humanas y materiales ( Haeberli et al., 2013;Hoffmann y Weggenmann, 2013;Worni, Huggel y Stoffel, 2012;Booth y Punt, 2012;Jain et al., 2012;Mergili et al., 2012;Bajracharya y Mool, 2009;Harrison et al., 2006). En los Andes del Perú se han registrado repetitivos eventos GLOF en las últimas décadas con consecuencias en algunos casos devastadoras (Carey, 2010;Portocarrero, 2014). ...
... Además, para poder comprender en más detalle cambios en los factores climáticos a largo plazo y su posible impacto en la morfología (peri)glaciar, el desarrollo de las lagunas glaciares y cambios en las condiciones de amenaza, se debe contar con una mayor red de monitoreo meteorológica, glaciar y geomorfológica. Actualmente, no existe una red de monitoreo glaciar y sísmico sistemático ni en la Cordillera de Vilcabamba, ni en otras cordilleras vecinas (Hoffmann y Weggenmann, 2013). ...
In recent decades, glaciers in different high-mountain regions have experienced unprecedented shrinkage since the end of the Little Ice Age (LIA). This process triggers the formation and growth of glacier lakes, which in combination with other potential hazard components can result in more likely conditions prone to the occurrence of disasters, such as Glacier Lake Outburst Floods (GLOFs). In the Peruvian Andes, multiple GLOFs have caused a large number of human and material losses, but hazard-based data collection and implementation of lake monitoring programs are scarce in this region.
This study focuses on lake and glacier area changes in the little studied Cordillera Vilcabamba (Cusco and
Apurimac, Peru). We present a multi-temporal and semiautomatic framework based on the Normalized Difference Water Index (NDWI) and Normalized Difference Snow
Index (NDSI), using Landsat TM 5 and OLI 8 images in the period 1991-2014. Our results corroborate a strong
glacier area shrinkage of 51% between 1991 (201.0 km2) and 2014 (98.9 km2). In the same period, the number of lakes (total lake surface) has increased from 247 (4.1 km2) in 1991 to 329 (5.2 km2) in 2014, which corresponds to an accelerated growth of 0.8% (0.6%) from 1991 to 2001 and 2.3% (1.7%) from 2010 to 2014, respectively. The strongest lake growth has been identified in high-altitudinal areas (4400-4800 masl) particularly for the last period (2010-2014), which might be correlated to current deglaciation processes and changes in geomorphologic features. The lake discrimination and potential hazard analysis were performed in a four-step protocol, primarily based on lake surface variations and a possible GLOF exposure of villages downstream. Further criteria were applied, including (a) glacier-lake distance, (b) dam type, (c) formation period, (d) critical slopes and (e) volume estimations. A total of 52 “indicator lakes” have been identified, of which 13 glacier lakes are connected to 15 exposed villages down valley. Two of these lakes have been classified in a low-medium potential hazard level and three in a medium-high level.
Our study results have several implications for future research and water management. Ongoing glacier shrinkage and lake development generate serious hazard and potential risk conditions. Nonetheless, there are opportunities for (integrated) future water management considering the growing need for new reservoirs, for example, for growing agriculture and hydropower water demand in the region. The presented methodology facilitates an effective and extended hazard analysis which should be further corroborated with additional in-situ data and criteria applied to other glaciated mountain ranges. Future research should focus on further development of a comprehensive, continuous and standardized hazard and risk analysis, in connection with glacier lake monitoring.
... In Peru in 1941, an outpouring destroyed the village of Huaraz affecting 5,000 people (Carey 2010). In Bolivia, the risk of disaster related to glacial shrinkage is lower, but, according to Hoffmann and Weggenmann (2012), there is still concern with the danger of GLOFs in certain parts of the country. In 2009, a glacial lake above a small village in Apolobamba's Cordillera sent a wave of water downstream, flooding cultivated fields, destroying local roads, and killing some domestic animals. ...
... In Ecuador, the glacier Cotacachi completely melted over the past decade, considerably affecting agriculture and the local tourism sector (Rhoades 2008;Rhoades et al. 2006). Finally, authors studying GLOF risk suggest that relocation is an option to avoid disasters for parts of exposed villages (Hoffmann and Weggenmann 2012). ...
This article examines the role of glacial retreat on human migration in the Bolivian Andes—a topic with virtually no scholarly focus, yet of critical importance in the era of global climate change. Glacial melting has increased since the 1980s, and popular reports often suggest there will be significant impacts on local populations, including migration. Based on interviews with local residents, both migrants and nonmigrants, as well as topical experts, this study suggests that residents do, indeed, have serious concerns about future livelihood conditions in the Bolivian Andes. Even so, glacial retreat has not triggered new migration flows and has had a limited impact on the existing migratory patterns.
... Se puede suponer que esta tendencia se mantendrá, y la superficie y la masa glaciar existente en 2012 se reducirían a la mitad en 2030 (véase la Figura 12.2). En cuanto a los glaciares menores, situados actualmente en alturas por debajo de los 5.600 metros de altitud, se estima su pérdida total Hoffmann & Weggenmann, 2011). En relación con la ocurrencia de eventos extremos, de acuerdo con las tendencias generales previstas por el IPCC (2007), se estima un aumento de estos para las próximas décadas que se expresaría fundamentalmente en inundaciones más frecuentes y extendidas en época de lluvias; sequías más severas, prolongadas y con efectos en mayores extensiones de territorio, y precipitaciones extremas, granizadas y tormentas más frecuentes y más fuertes, así como heladas más pronunciadas. ...
Se centra en la Amazonía sudoeste contemporánea (es decir, desde el año 2000), un período en el que los cambios se han acelerado notablemente porque las fuerzas motrices claves se han intensificado y los procesos de cambio han sido, a su vez, modificados, tanto en su estructura como en su ritmo.
... Dust storm and desert climate around Aral Sea (Micklin et al., 2014); Flooding (human induced climate change) (Linear in terms of biophysical feedbacks, tipping possible in the ecological system) Glacial retreat (Hoffmann and Weggenmann, 2013) Ecosystem collapse due to unnatural flow regimes (dams and reservoirs) Loss of flow variation. (Linear in terms of biophysical feedbacks, tipping possible in the ecological system) Dolphin population dependence on natural flows in the Gangetic basin (Choudhary et al., 2012); Global flow regulation and fragmentation (Nilsson et al., 2005); (Cowen, 1999) agricultural land degradation salinization canals silt-choked deathblow=flood-generatedshift of river courses water supply collapse agricultural system collapse socio-economic collapse of rich Arab culture(time of Sheherazade) Iraq remained desert >600 yrs (linear collapse) ...
Water is indispensable for Earth resilience and sustainable development. The capacity of social-ecological systems to deal with shocks, adapting to changing conditions and transforming in situations of crisis are fundamentally dependent on the functions of water to e.g., regulate the Earth’s climate, support biomass production, and supply water resources for human societies. However, massive, inter-connected, human interference involving climate forcing, water withdrawal, dam constructions, and land-use change have significantly disturbed these water functions and induced regime shifts in social-ecological systems. In many cases, changes in core water functions have pushed systems beyond tipping points and led to fundamental shifts in system feedback. Examples of such transgressions, where water has played a critical role, are collapse of aquatic systems beyond water quality and quantity thresholds, desertification due to soil and ecosystem degradation, and tropical forest dieback associated with self-amplifying moisture and carbon feedbacks. Here, we aggregate the volumes and flows of water involved in water functions globally, and review the evidence of freshwater related linear collapse and non-linear tipping points in ecological and social systems through the lens of resilience theory. Based on the literature review, we synthesize the role of water in mediating different types of ecosystem regime shifts, and generalize the process by which life support systems are at risk of collapsing due to loss of water functions. We conclude that water plays a fundamental role in providing social-ecological resilience, and suggest that further research is needed to understand how the erosion of water resilience at local and regional scale may potentially interact, cascade, or amplify through the complex, globally hyper-connected networks of the Anthropocene. Keywords: Water sustainability, Green-Blue water, Earth resilience, Global water system, Regime shift, Water conflict
... This lake is graded as low risk (a result that is sustained throughout the sensitivity analyses -Tables 4 and 5) due to both downstream impact parameters (IM.1 and IM.2) falling into the low impact category -there is no significant population or infrastructure in the immediate floodpath downstream (except farmland and a minor road). The Passu lake, Keara lake and lake 513 GLOF events are known to have damaged roads or bridges, or to have increased downstream sedimentation causing malfunction of water-treatment plants or damage to agricultural land (Ashraf et al., 2012;Carey et al., 2012;Hoffmann and Weggenmann, 2013;Klimeš et al., 2014;Vilímek et al., 2015). Nevertheless, they did not cause any casualties or fatalities. ...
Glacial Lake Outburst Floods (GLOFs) represent a significant
threat in deglaciating environments, necessitating the development of
GLOF hazard and risk assessment procedures. Here, we outline a Multi-
Criteria Decision Analysis (MCDA) approach that can be used to rapidly
identify potentially dangerous lakes in regions without existing tailored
GLOF risk assessments, where a range of glacial lake types exist, and
where field data are sparse or non-existent. Our MCDA model (1) is deskbased
and uses freely and widely available data inputs and software, and
(2) allows the relative risk posed by a range of glacial lake types to be
assessed simultaneously within any region. A review of the factors that
influence GLOF risk, combined with the strict rules of criteria selection
inherent to MCDA, has allowed us to identify 13 exhaustive, nonredundant,
and consistent risk criteria. We use our MCDA model to assess
the risk of 16 extant glacial lakes and 6 lakes that have already
generated GLOFs, and found that our results agree well with previous
studies. For the first time in GLOF risk assessment, we employed
sensitivity analyses to test the strength of our model results and
assumptions, and to identify lakes that are sensitive to the criteria and
risk thresholds used. A key benefit of the MCDA method is that
sensitivity analyses are readily undertaken. Overall, these sensitivity
analyses lend support to our model, although we suggest that further work
is required to determine the relative importance of assessment criteria,
and the thresholds that determine the level of risk for each criterion.
As a case study, the tested method was then applied to 25 potentially
dangerous lakes in the Bolivian Andes, where GLOF risk is poorly
understood; 3 lakes are found to pose 'medium' or 'high' risk, and
require further detailed investigation.
... For the people who live in the Cordillera Apolobamba region -home to many of Bolivia's rapidly melting tropical glaciers -the impact of climate change is a lived reality. From risks associated with glacial lake outburst floods (Hoffmann and Weggenmann, 2012) to a decreasing amount of water supply for communities and cities across the Andes (Fabricant, 2013, p. 159), melting glaciers pose a definite threat to the Kallawaya. However, risks from melting glaciers aside, the increase in temperatures due to global warming pose other myriad threats to the Kallawaya tradition. ...
Relative to research efforts in higher latitiudes, the impact of climate shifts in the tropical treeline remains understudied. Little is known about the tree growth dynamics and climate response at this treeline over the past few centuries, and at present under a rapidly changing environment. Here we provide information on recent changes in tree-ring patterns of Polylepis pepei BB.Simpson, a tropical tree species that grows in a monospecific forest at the elevational treeline in the Andes-Amazon ecotone of Bolivia and identify factors that limit its radial growth. We first developed a ring width (RW) chronology spanning 1867–2018 C.E. using dendrochronological methods and independently verified annual periodicity with radiocarbon dating. The RW chronology indicates a significant (p < 0.01) radial growth decline in P. pepei since 1997, a trend that mirrors a decrease reported in other Polylepis species from the drier central Andes of South America. P. pepei tree-ring width (RW) was mostly limited by mean, minimum, and maximum temperature and precipitation during austral summer (November–January). Over the instrumental period (1981–2019) prior-year temperatures negatively affected current-year tree growth (p < 0.05), while prior-year wet conditions were associated with higher growth (p < 0.05). Gridded temperature records (1901–2019) showed a significant increase in minimum temperatures and a decline in the diurnal temperature range since 1967, which may reduce orographic convection and water availability at higher elevations where our forest is located. In situ daily measurements from dataloggers in the forest recorded higher temperatures and lower relative humidity values when data was available. Our results suggest less moisture availability associated with warming conditions was related to the observed tree-growth decline. If temperature continues to rise at current rates, one of the highest-elevation tree species on the globe, P. pepei, could face severe consequences. This work provides insights into the past and historical trends of a tropical Andean treeline, which shows a recent decline also observed in other high-elevation forests (4657–4800 m.a.s.l.) of tropical South America (>17° S).
The prevalence and impacts of glacier lake outburst floods (GLOFs) in all glacierized mountain ranges globally underlines the importance of GLOF disaster risk management (DRM). A large variety of types of GLOF DRM measures exists, targeting the reduction of the hazard of a potential GLOF, of the exposure, or of the vulnerability of people and infrastructure. A wide range of such measures have been implemented in different mountain regions all over the world since the mid 20th century. While many of these measures have been reported, there are relevant gaps in the systematic documentation, analysis, and evaluation of GLOF DRM measures globally. A comprehensive compilation, classification and evaluation of GLOF DRM measures is required to establish a guidance for best practice approaches. DRM measures aiming at a reduction of the hazard component are typically structural measures, while vulnerability is addressed mainly by nonstructural measures. Hazard and exposure reduction measures cover all temporal ranges from short- to long-term interventions. The design and implementation of GLOF DRM measures is demanding due to harsh environmental conditions, remoteness, and rapidly changing hazard and risk situations on the one hand. Institutional and organizational aspects related to the funding, planning, and implementation of such measures, on the other hand, pose further challenges to successful GLOF DRM.
The Bolivian Andes have experienced sustained and widespread glacier area reduction and volume loss in recent decades. This study finds that from 1986 to 2018 glacier areas have shrunk from 529 km2 to 281 km2 (49 %) in the Bolivian Cordillera Oriental. Glacier melting and recession has been accompanied by the development of proglacial lakes, which can pose a glacial lake outburst flood (GLOF) risk to downstream communities. Therefore, glacier bed topographies were extracted and illustrate the potential development of 68 future lakes. Eight of these lakes possess populations downstream. A simple geometric model (MC-LCP) was used to model GLOFs from these potential future lakes, illustrating that ~1100 to ~2900 people could be affected by flooding if these lakes were to appear and to burst. The rest of this work is dedicated on the estimation of the risk from current, already existing lakes. Multi-Criteria Decision Analysis (MCDA) was used to rapidly identify potentially dangerous proglacial lakes in regions around the world without existing tailored GLOF risk assessments, where a range of proglacial lake types exist, and where field data are sparse or non-existent. After testing the robustness of the MCDA model against a number of past GLOFs, it was applied to the Bolivian Cordillera Oriental. From the 25 lakes possessing populations downstream, 3 lakes were found to pose ‘medium’ or ‘high’ risk, and required further detailed investigation. Since no attempt has yet been made to model GLOF inundation downstream from these proglacial lakes, 2m resolution DEMs were generated from stereo and tri-stereo SPOT 6/7 satellite images to drive a hydrodynamic model (HEC-RAS 5.0.3) of GLOF flow. The model was tested against field observations of a 2009 GLOF from Keara, in the Cordillera Apolobamba, and was shown to reproduce realistic flood depths and inundation. The model was then used to model GLOFs from Pelechuco lake (Cordillera Apolobamba) and Laguna Arkhata and Laguna Glaciar (Cordillera Real). In total, ~1100 to ~2200 people could be directly affected by outburst flooding.
Tropical glaciers are sensitive to climate variations and more than 95% of them are located in the South American Andes. The present study estimated current glacial surface extent in the eastern mountain ranges of Bolivia. Glacial surface changes were estimated using satellite images and available literature between 1975 and 2016. Sentinel-2 images were used, for the first time, for glacier mapping in the tropical Andes and Landsat imagery for glacial surface area change. Estimated glacial area reduction between 1975 and 2016 in Cordilleras; Apolobamba, Real, and Tres Cruces–Nevado Santa Vera Cruz was 48.8, 50.7, and 59.4%, respectively. Overall glacier shrinkage between 1975 and 2016 was 51% (from 543.9 to 266.5 km2). For the same period, total glacier area reduction in the Bolivian Cordillera Oriental below 5000 m a.s.l. was 91%. A prevalent southward glacial orientation was accounted for glaciers along the Cordillera Oriental of Bolivia. Furthermore, meteorological data analysis showed a positive trend in the air temperature and a negative trend in precipitation in the region. If current environmental conditions persist, no glacial surface at low elevations (5000 m a.s.l.) will remain in the future. This may seriously influence water resources in the region. Nevertheless, glaciers above 5500 m a.s.l. are considered relatively stable.
Glaciers of the Bolivian Andes represent an important water resource for
Andean cities and mountain communities, yet relatively little work has
assessed changes in their extent over recent decades. In many mountain
regions, glacier recession has been accompanied by the development of
proglacial lakes, which can pose a glacial lake outburst flood (GLOF) hazard.
However, no studies have assessed the development of such lakes in Bolivia
despite recent GLOF incidents here. Our mapping from satellite imagery
reveals an overall areal shrinkage of 228.1 ± 22.8 km2
(43.1 %) across the Bolivian Cordillera Oriental between 1986 and 2014.
Shrinkage was greatest in the Tres Cruces region (47.3 %), followed by
the Cordillera Apolobamba (43.1 %) and Cordillera Real (41.9 %). A
growing number of proglacial lakes have developed as glaciers have receded,
in accordance with trends in most other deglaciating mountain ranges,
although the number of ice-contact lakes has decreased. The reasons for this
are unclear, but the pattern of lake change has varied significantly
throughout the study period, suggesting that monitoring of future lake
development is required as ice continues to recede. Ultimately, we use our
2014 database of proglacial lakes to assess GLOF risk across the Bolivian
Andes. We identify 25 lakes that pose a potential GLOF threat to downstream
communities and infrastructure. We suggest that further studies of potential
GLOF impacts are urgently required.
Glaciers of the Bolivian Andes represent a vital water resource for Andean cities and mountain communities, yet relatively little work has assessed changes in their extent over recent decades. In many mountain regions, glacier recession has been accompanied by the development of proglacial lakes, which can pose a glacial lake outburst flood (GLOF) hazard. However, no studies have assessed the development of such lakes in Bolivia despite recent GLOF incidents here. Our mapping from satellite imagery reveals an overall areal shrinkage of 228.1 ± 22.8 km2 (43.1%) across the Bolivian Cordillera Oriental between 1986 and 2014. Shrinkage was greatest in the Tres Cruces region (47.3%), followed by the Cordillera Apolobamba
(43.1%) and Cordillera Real (41.9%). A growing number of proglacial lakes have developed as glaciers have receded, in accordance with trends in most other deglaciating mountain ranges, although the number of ice-contact lakes has decreased.
The reasons for this are unclear, but the pattern of lake change has varied significantly throughout the study period, suggesting that monitoring of future lake development is required as ice continues to recede. Ultimately, we use our 2014 database of proglacial lakes to assess GLOF risk across the Bolivian Andes. We identify 25 lakes that pose a potential GLOF threat to downstream communities and infrastructure. We suggest that further studies of potential GLOF impacts are urgently required.
Damage due to glacier floods in the Swiss Alps occurs about once every two years at present, despite the pronounced retreat of glaciers during the twentieth century and the installation of many water reservoirs, which act as flood retention basins. Over half (60 to 70%) of the observed floods are caused by outbursts of marginal glacier lakes or sudden breaks of ice dams, and 30 to 40% by ruptures of water pockets. In a glacierized mountain region as densely populated as the Swiss Alps, even debris flows triggered by outbursts of very small water masses may be dangerous. Historical information about glacier floods in the Swiss Alps, although incomplete and heterogeneous, is used as an empirical basis for an attempt to recognize potential hazards at an early stage by considering outburst processes, volumes of water involved, potential peak-discharge values, lithology and inclination within the reach of glacier streams.
Glacier lakes are a common phenomenon in high mountain areas. Outbursts from glacier lakes have repeatedly caused the loss of human lives as well as severe damage to local infrastructure. In several high mountain ranges around the world, a grave uncertainty about the hazard potential of glacier lakes still exists, especially with respect to the effects of accelerating rates of glacier retreat as a consequence of atmospheric warming. Area-wide detection and modeling of glacier lake hazard potentials is, therefore, a major challenge. In this study, an approach integrating three scale levels allows for the progressive focus on critical glacier lakes. Remote sensing methods for application in glacier lake hazard assessment are presented, and include channel indexing, data fusion, and change detection. Each method matches the requirements of a certain scale level. For estimating potential disaster amplitudes, assessments must be made of maximum discharge and runout distance of outbursts floods and debris flows. Existing empirical relations are evaluated and complementary ones as derived from available data are proposed. Tests with observations from a recent outburst event from a moraine-dammed lake in the Swiss Alps show the basic applicability of the proposed techniques and the usefulness of empirical relations for first hazard assessments. In particular, the observed runout distance of the debris flow resulting from the outburst does not exceed the empirically estimated maximum runout distance. A list of decision criteria and related remote sensing techniques are discussed in conclusion. Such a list is an essential tool for evaluating the hazard potential of a lake. A systematic application of remote sensing based methods for glacier lake hazard assessment is recommended.
Glacial hazards such as ice avalanches, glacial lake outburst floods, and debris flows have caused severe damage,in populated,mountain,regions such as the Swiss Alps. Assessment,of such hazards must consider basic glaciological, geomorphological, and hydraulic principles together with experience gained from previous events. An ap- proach is presented here to assess the maximum,event magnitude,and probability of occurrence,of glacial hazards. Analysis of magnitude,is based on empirical relationships derived from published case histories from the Swiss Alps and other mountain,regions. Probability of occurrence,is difficult to estimate because of rapid changes in the nature of glacial systems, the low frequency of events, and the high complexity of the involved processes. Here, the probability is specified in qualitative and systematic terms based on indicators such as dam type, geometry, and freeboard height (for glacial lakes) and tendency of avalanche repetition, precursor events, and increased water supply to the glacier bed (for ice avalanche,events). The assessment,procedures are applied to a recent lake outburst with subsequent,debris flow and to an ice avalanche,in the Swiss Alps. The results yield reasonable event maxima,that were not exceeded,by actual events. The methods,provide first-order assessments,and may,be applied in dynamic,mountain,environments,where population and infrastructure growth,require continuous,evaluation of hazards. Key words: glacial hazards, lake outburst, debris flow, ice avalanche, hazard assessment procedure, probability of occur-
The volume changes of 21 glaciers in the Cordillera Real have been determined between 1963 and 2006 using photogrammetric measurements. These data form the longest series of mass balances obtained with such accuracy in the tropical Andes. Our analysis reveals that temporal mass balance fluctuations are similar, revealing a common response to climate over the entire studied region. The mass of these glaciers has clearly been decreasing since 1975 without any significant acceleration of this trend over recent years. We have found a clear relationship between the average mass balance of these glaciers as a function of exposure and altitude. From this relationship, the ice volume loss of 376 glaciers has been assessed in this region. The results show that these glaciers lost 43% of their volume between 1963 and 2006, essentially over the 1975–2006 period and 48% of their surface area between 1975 and 2006.
) clean glaciers by as much as 50 percent of the ca. 1955 volumes at elevations ranging from approximately 5500-5600 masl, (c) the formation of new and potentially dangerous glacial lakes that had been debris covered glaciers (D-Type) in the 1950s, and (d) the ablation of most of the D-Type glaciers re-photographed. The findings support and complement those of recent investigations based almost entirely on remote sensing and computer modelling. However, detailed, on-the-ground field studies of potential climate change impacts on the people and environments of the Mt. Everest region are disturbingly absent. I suggest that only by systematically combining field and laboratory-based investigations will we acquire the tools to enable us to identify the real threats, non-threats, and ways in which local people can adapt and reduce vulnerabilities to climate change.
Damage due to glacier floods in the Swiss Alps occurs about once every two years at present, despite the pronounced retreat of glaciers during the twentieth century and the installation of many water reservoirs, which act as flood retention basins. Historical information about glacier floods in the Swiss Alps, although incomplete and heterogeneous, is used as an empirical basis for an attempt to recognize potential hazards at an early stage by considering outburst processes, volumes of water involved, potential peak-discharge values lithology and inclination within the reach of glacier streams. -from Author
Observations on glacier extent from Ecuador, Peru and Bolivia give a detailed and unequivocal account of rapid shrinkage of tropical Andean glaciers since the Little Ice Age (LIA). This retreat however, was not continuous but interrupted by several periods of stagnant or even advancing glaciers, most recently around the end of the 20th century. New data from mass balance networks established on over a dozen glaciers allows comparison of the glacier behavior in the inner and outer tropics. It appears that glacier variations are quite coherent throughout the region, despite different sensitivities to climatic forcing such as temperature, precipitation, humidity, etc. In parallel with the glacier retreat, climate in the tropical Andes has changed significantly over the past 50–60 years. Temperature in the Andes has increased by approximately 0.1 °C/decade, with only two of the last 20 years being below the 1961–90 average. Precipitation has slightly increased in the second half of the 20th century in the inner tropics and decreased in the outer tropics. The general pattern of moistening in the inner tropics and drying in the subtropical Andes is dynamically consistent with observed changes in the large-scale circulation, suggesting a strengthening of the tropical atmospheric circulation. Model projections of future climate change in the tropical Andes indicate a continued warming of the tropical troposphere throughout the 21st century, with a temperature increase that is enhanced at higher elevations. By the end of the 21st century, following the SRES A2 emission scenario, the tropical Andes may experience a massive warming on the order of 4.5–5 °C. Predicted changes in precipitation include an increase in precipitation during the wet season and a decrease during the dry season, which would effectively enhance the seasonal hydrological cycle in the tropical Andes.
Moraine-dammed lakes are common in the high mountains of British Columbia. Most of these lakes formed when valley and cirque glaciers retreated from advanced positions achieved during the Little Ice Age. Many moraine dams in British Columbia are susceptible to failure because they are steep-sided, have relatively low width-to-height ratios, comprise loose, poorly sorted sediment, and may contain ice cores or interstitial ice. In addition, the lakes commonly are bordered by steep slopes that are prone to snow and ice avalanches and rockfalls. Moraine dams generally fail by overtopping and incision. The triggering event may be a heavy rainstorm, or an avalanche or rockfall that generates waves that overtop the dam. The dam can also be overtopped by an influx of water caused by sudden drainage of an upstream ice-dammed lake (jökulhlaup). Melting of moraine ice cores and piping are other possible failure mechanisms. Failures of moraine dams in British Columbia produce destructive floods orders of magnitude larger than normal streamflows. Most outburst floods are characterized by an exponential increase in discharge, followed by an abrupt drop to background levels when the water supply is exhausted. Peak discharges are controlled by dam characteristics, the volume of water in the reservoir, failure mechanisms, and downstream topography and sediment availability. For the same potential energy at the dam site, floods from moraine-dammed lakes have higher peak discharges than floods from glacier-dammed lakes. The floodwaters may mobilize large amounts of sediment as they travel down steep valleys, producing highly mobile debris flows. Such flows have larger discharges and greater destructive impact than the floods from which they form. Moraine dam failures in British Columbia and elsewhere are most frequent following extended periods of cool climate when large lateral and end moraines are built. A period of protracted warming is required to trap lakes behind moraines and create conditions that lead to dam failure. This sequence of events occurred only a few times during the Holocene Epoch, most notably during the last several centuries. Glaciers built large moraines during the Little Ice Age, mainly during the 1700s and 1800s, and lakes formed behind these moraines when climate warmed in the 1900s. Twentieth-century climate warming is also responsible for recent moraine dam failures in mountains throughout the world. Warming from the late 1800s until about 1940 and again from 1965 to today destabilized moraine dams with interstitial or core ice. The warming also forced glaciers to retreat, prompting ice avalanches, landslides, and jökulhlaups that have destroyed some moraine dams.
A la fecha existe un importante número de estudios que demuestran la tendencia actual hacia la desaparición de los glaciares bolivianos. El presente estudio del impacto socio-económico del retroceso de los glaciares es un primer intento de obtener un panorama sobre dónde y qué cambios se podría esperar en un futuro cercano. Aproximadamente el 80% de los glaciares bolivianos tienen una superficie menor a 0,5 km²; por lo tanto, es muy probable que la mayoría de ellos hayan desaparecido completamente durante los próximos 10 a 15 años. Los impactos socio-económicos se harán notar sobre todo en un nivel local, y los elementos más preocupantes son, por un lado, la falta de investigación sobre el tema y por otro, la falta de una conciencia pública sobre el problema en la población boliviana y que una parte socio-políticamente importante y numerosa de la población será probablemente más afectada, la metrópoli La Paz – El Alto.
Les lacs glaciaires et la variabilité climatique dans les Andes depuis le dernier maximum glaciaire.
Des carottages réalisés dans des lacs glaciaires des Andes tropicales et subtropicales ont fourni des registres paléoclimatiques continus couvrant le Dernier Maximum Glaciaire et l'Holocène. Des datations 14C sur sédiments lacustres et sur tourbes indiquent que le maximum de la dernière glaciation s'est produit antérieurement au Dernier Maximum Glaciaire Global (18 ka BP). La plupart des lacs ont un âge inférieur à 13 ka BP, ce qui signifie que l'avancée des glaciers correspondant au Pleistocène terminal aurait culminé aux alentours de 14 ka BP. Des avancées durant le Tardi-glaciaire sont enregistrées dans plusieurs sites lacustres. À partir de 10 ka BP, les glaciers ont reculé au-delà de leurs limites actuelles. La sécheresse de l'Holocène moyen est repérée dans la stratigraphie de nombre de lacs, y compris le lac Titicaca. Cette phase d'aridité est suivie par une remontée des niveaux lacustres et une réavancée des glaciers à la fin de l'Holocène.
Climate models predict that greenhouse warming will cause temperatures to rise faster at higher than at lower altitudes. In
the tropical Andes, glaciers may soon disappear, with potentially grave consequences for water supplies.
The retreat of glaciers since 1927 in Cordillera Blanca has produced dangerous lakes at the front of many glaciers. All the known data, most of them unpublished, are reviewed. The known aluviones are listed, and those of Chavin, Quebrada Los Cedros and Artesoncocha described in full. In these three cases a breach in the front moraine came from big ice falls into the lake. The protective devices made on the outlets are described, as well as the effects of the big earthquake on 31 May 1970. In the case of Laguna Parón, which keeps its level thanks to infiltrations, the fluctuations of the discharge of the springs as related to the level of the lake from 1955 to 1969 are reported. The projects for lowering the level of Laguna Parón and for emptying Safuna Alta are described. The latter partially emptied in fact by piping after the earthquake, allowing a final solution.
In western Canada, existing and former lakes dammed by landslides, moraines, and glaciers have drained suddenly to produce floods, orders of magnitude larger than normal streamflows. Landslide dams consisting of failed bedrock generally are stable, whereas those comprising Quaternary sediments or volcanic debris fail soon after they form, typically by overtopping and incision. Moraine dams are susceptible to failure because they are steep-sided and consist of loose, poorly sorted sediment. Irreversible rapid incision of a moraine dam may result from a large overflow associated with a severe rainstorm, avalanche, or rockfall. Some glacier-dammed lakes drain suddenly through englacial and subglacial tunnels to produce large floods. -from Authors
The retreat of glaciers since 1927 in Cordillera Blanca has produced dangerous lakes at the front of many glaciers. All the known data, most of them unpublished, are reviewed. The known aluviones are listed, and those of Chavin, Quebrada Los Cedros and Artesoncocha described in full. In these three cases a breach in the front moraine came from big ice falls into the lake. The protective devices made on the outlets are described, as well as the effects of the big earthquake on 31 May 1970. In the case of Laguna Parón, which keeps its level thanks to infiltrations, the fluctuations of the discharge of the springs as related to the level of the lake from 1955 to 1969 are reported. The projects for lowering the level of Laguna Parón and for emptying Safuna Alta are described. The latter partially emptied in fact by piping after the earthquake, allowing a final solution.
Nine potentially dangerous glaciers were identified from flight observations which were carried out in the Eastern and Central Himalayas on pre- and post-monsoon seasons in 1991. Field surveys were made at the beginning of April, 1992 to Imja Glacier lake located in Khumbu district of Eastern Nepal. This is one of the most dangerous typical glacier lakes that were identified by the flight observations. The field surveys revealed the maximum depth of the lake to be 98.5 m and the total amount of stored water to be 28 million m3. Since this lake is dammed up by ice-cored moraine it is concluded as one of the most dangerous glacier lakes in the Himalayas. -from Authors
Climate change is probably the main challenge humanity is facing in the twenty-first century, and even though Bolivia belongs to the nations least responsible for global greenhouse gas output, the impacts of climate change and global warming (glacier retreat in the Cordillera mountain range; droughts in the Altiplano, the inner Andean dry valleys, and the Chaco region; inundations in the Beni lowlands) are affecting an ever increasing number of people. Thus, to tackle the impacts of climate change in Bolivia is not only a task for political authorities at national, departmental, municipal, or communal level, but also one that has to be taken up by the management practitioners of the country’s protected areas. Nonetheless, the impacts of climate change are not yet a central issue in the management of the Bolivian National Protected Area System.
This article shows how protected areas are “victims” of climate change, since their biodiversity is being affected by rising temperatures and changes in the hydrological regime; we also analyse in what ways Bolivia’s protected areas are a fundamental element in the drafting of mitigation and adaptation strategies, considering the importance they have in maintaining ecosystem resilience and the provision of environmental services.
Glaciers and snowfields can form potential hazards in the Himalayas, and in similarly glacierised regions of the world. Some glaciological phenomena can have significant impacts upon society over a short time scale (minutes–days), such as ice/snow avalanches and glacial floods. Other related hazards can be equally serious but less obvious when considered on a much longer time scale (months–years–decades), such as glacier volume fluctuations leading to water resource problems. Only when humans and their activities become vulnerable to glacier-related processes is there considered to be a hazard risk.As glaciers recede in response to climatic warming, the number and volume of potentially hazardous moraine-dammed lakes in the Himalayas is increasing. These lakes develop behind unstable ice-cored moraines, and have the potential to burst catastrophically, producing devastating Glacial Lake Outburst Floods (GLOFs). Discharge rates of 30,000 m3 s−1 and run-out distances in excess of 200 km have been recorded. Despite the scale of the risk, it is possible to assess and mitigate hazardous lakes successfully. Hazard assessment using satellite images has been effective for remote areas of Bhutan, and remediation techniques successfully developed in the Peruvian Andes are now being deployed for the first time in Nepal.
Reporte preliminar del desastre natural en la comunidad de Keara. 6 noviembre
- Apaza Ticona
Áreas protegidas de Bolivia, Situación y Perspectivas de gestión
- Arnold Torrez
- Barroso Pauletti
Mountain glaciers: on thin ice (eds) Mountains and climate change: from understanding to action
- W Haeberli
- M Zemp
Natural hazards and risk in mountains: the potential impacts of climate change (eds) Mountains and climate change: from understanding to action
- C Marty
El uso de la Tierra y los Recursos de la Biodiversidad en las Áreas Protegidas de Bolivia, Un análisis crítico con propuestas para su conservación y manejo sostenible
- M O Ribera
- M Libermann
Policy and Perspective, United Nations Environment Programme. Disaster Risk Management in Mountains Series
- J Eamer
- C Lambrechts
- P Prestrud
- O Young
Segundo informe de los talleres de percepciones del cambio climático, comunidades Canuhuma y Ayllu Puyo Puyo
- F Canqui
El cambio climático y las áreas protegidas de Bolivia
- D Hoffmann
- Sg Beck
- N Paniagua
- Rp López
High mountain glaciers and climate change: Challenges to human livelihoods and adaptacion
- B P Kaltenborn
- C Nellemann
- I I Vistnes
International Centre for Integrated Mountain Development Formation of glacial lakes in the Hindu Kush-Himalayas and GLOF risk assessment, International Centre for Integrated Mountain Development
- Jd Ives
- Rb Shrestha
- P Mool
Die Gletscher der bolivianischen Anden eine photogrammetrisch-kartographische Bestandsaufnahme der Gletscher Boliviens als Grundlage für klimatische Deutungen und Potential für die wirtschaftliche Nutzung
- E Jordan
Responding to the collapse of mountain ecosystem health and natural resource management institutions in Peru, IHDP Update
- López Sotomayor
Programa de Monitoreo Integral del Área Natural de Manejo Integrado Nacional Apolobamba. Propuesta de Trabajo, technical document prepared for
- R Tarquino
- P Flores
Cambio Climático y manejo de riesgos en alta montana: Inventario de las lagunas glaciares de la Cordillera Real de Bolivia
- D Hoffmann
Climate change in mountains Mountains and climate change: from understanding to action
- U Neu
Andean glaciers vanish, add socio-economic strains. Focal Point Canada’s Spotlight on the
- D Hoffmann
Climate change and protected areas in the tropical Andes
- D Hoffmann
- I Oetting
- C A Arnillas
- R Ulloa
Formation of glacial lakes in the Hindu Kush-Himalayas and GLOF risk assessment
- J D Ives
- R B Shrestha
- P Mool
Enciclopedia Geográfica de
- I Montes De Oca
Quakes could rupture glacial lakes
- N Singh Khadka
Global glacier changes facts and figures
- WGMS
Climate change 2007: the physical science basis, contribution of working group I to the fourth assessment report of the IPCC, technical summary Intergovernmental Panel on Climate Change
- IPCC