Current and future glacier and lake assessment in the deglaciating Vilcanota-Urubamba basin, Peruvian Andes

Glacier shrinkage is a strong driver of change for mountain hydrology and landscape development and bears multiple risks as well as new options for human livelihoods. In the tropical Andes, current rates of glacier loss are investigated to some point but associated future extent of both vanishing glacier and forming lake areas and volumes are poorly explored. This study combines an analysis of current (1988–2016) and future (2050/2100) glacier and lake development in the Vilcanota-Urubamba basin (Cusco, Southern Peru). Total glacier area (volume) decreased by 37.3% (20.5%) from 226.1 km2 (8.122 km3) in 1988 to 141.7 km2 (6.457 km3) in 2016. Adjacent lakes increased in area (number) by 15.5% (18.3%) from 23.3 km2 (460 lakes) in 1988 to 26.9 km2 (544 lakes) in 2016 while corresponding lake volume has grown by 9.7% from 0.637 km3 to 0.699 km3, respectively. High spatiotemporal variability can be observed in the basin, with strongest glacier shrinkage in the lower lying northwest (Cordilleras Urubamba and Vilcabamba) and highest growth and lake extent in the Altiplano region of the southeast (Cordillera Vilcanota and Quelccaya ice cap). Future glacier areas could substantially decrease between 40.7% (RCP2.6) and 44.9% (RCP8.5) within the next decades (2031–2060) and between 41.4% and 92.7%, respectively, within this century (2071–2100). Hence, Andean landscapes would transform into mostly glacier-free areas with some remaining ice-covered summits over ~6000m asl. and this would imply a loss of permanently stored water of several km3. Until the end of this century, important future lake areas could develop and continue to grow between 3.2% (RCP 2.6) and 6.0% (RCP8.5) with an associated volume increase of 0.032 km3 (4.6%) and 0.041 km3 (5.9%), respectively. Our current baseline and future projections suggest that a decrease of glacier shrinkage is also followed by a slowdown in lake formation and particularly volume growth which might have already developed or occur in the near-future. Under the depicted scenarios of change, strong emphasis needs to be promptly put on feasible water management and storage options as robust adaptation measures tackling high uncertainties, risks and complex hydroclimatic and socioenvironmental intertwining

Current and future water balance for coupled human-natural systems – Insights from a glacierized catchment in Peru

Study region Santa River basin, Peru. Study focus In the Andes of Peru, climate change and socio-economic development are expected to jeopardize future water availability. However, little is known about the interplay of multiple climatic and non-climatic stressors and related processes driving water resource changes. We developed an integrated model that analyzes different trajectories of water availability including hydro-climatic (water supply) and socio-economic (water demand) variables with consistent multi-descriptor future scenarios until 2050. New hydrological insights for the region At the lower-basin outflow of Condorcerro, mean annual water availability is projected to increase by 10% ± 12% by 2050. This gain is mainly driven by an increase in annual precipitation amounts of about 14% (RCP2.6) and 18% (RCP8.5), respectively, which was computed using a global climate multi-model ensemble. In contrast, mean dry-season water availability is projected to substantially decrease by 33% and 36% ( ± 24%) by 2050, for RCP2.6 and RCP8.5, respectively. This decline is driven by a combination of diminishing glacier discharge and increasing water demand both of which adopt a major role in the absence of considerable precipitation inputs. These seasonal differences highlight the need to adequately consider spatiotemporal scales within multi-scenario water balance models to support local decision-making. Our results elucidate the need for improvements in water management and infrastructure to counteract diminishing dry-season water availability and to reduce future risks of water scarcity

High-resolution grids of daily air temperature for Peru - the new PISCOt v1.2 dataset

Gridded high-resolution climate datasets are increasingly important for a wide range of modelling applications. Here we present PISCOt (v1.2), a novel high spatial resolution (0.01°) dataset of daily air temperature for entire Peru (1981–2020). The dataset development involves four main steps: (i) quality control; (ii) gap-filling; (iii) homogenisation of weather stations, and (iv) spatial interpolation using additional data, a revised calculation sequence and an enhanced version control. This improved methodological framework enables capturing complex spatial variability of maximum and minimum air temperature at a more accurate scale compared to other existing datasets (e.g. PISCOt v1.1, ERA5-Land, TerraClimate, CHIRTS). PISCOt performs well with mean absolute errors of 1.4 °C and 1.2 °C for maximum and minimum air temperature, respectively. For the first time, PISCOt v1.2 adequately captures complex climatology at high spatiotemporal resolution and therefore provides a substantial improvement for numerous applications at local-regional level. This is particularly useful in view of data scarcity and urgently needed model-based decision making for climate change, water balance and ecosystem assessment studies in Peru

Present and future water resources supply and demand in the Central Andes of Peru: a comprehensive review with focus on the Cordillera Vilcanota

Glaciers have been an important element of Andean societies and livelihoods as direct freshwater supply for agriculture irrigation, hydropower generation and mining activities. Peru’s mainly remotely living population in the Central Andes has to cope with a strong seasonal variation of precipitations and river runoff interannually superimposed by El Niño impacts. Direct glacier and lake water discharge thus constitute a vital continuous water supply and represent a regulating buffer as far as hydrological variability is concerned. This crucial buffer effect is gradually altered by accelerated glacier retreat which leads most likely to an increase of annual river runoff variability. Furthermore, a near-future crossing of the ‘peak water’ is expected, from where on prior enhanced streamflow decreases and levels out towards a new still unknown minimum discharge. Consequently, a sustainable future water supply especially during low-level runoff dry season might not be guaranteed whereas Peru’s water demand increases significantly

No-regret adaptation to climate change through management of glacial lakes in the Santa River Basin in Peru

Abstract and Poste

Future runoff from glacierized catchments in the Central Andes could substantially decrease

In Peru, about 50% of the energy is produced from hydropower plants. An important amount of this energy is produced with water from glaciated catchments. In these catchments river streamflow is furthermore needed for other socio-economic activities such as agriculture. However, the amount and seasonality of water from glacial melt is expected to undergo strong changes. As glaciers are projected to further decline with continued warming, runoff will become more and more sensitive to possible changes in precipitation patterns. Moreover, as stated by a recent study (Neukom et al., 2015), wet season precipitation sums in the Central Andes could decrease up to 19-33 % by the end of the 21st century compared to present-day conditions. Here, we investigate future runoff availability for selected glacierized catchments in the Peruvian Andes. In a first step, we apply a simplified energy balance and runoff model (ITGG-2.0-R) for current conditions

Progress and challenges in glacial lake outburst flood research (2017–2021):a research community perspective

Glacial lake outburst floods (GLOFs) are among the most concerning consequences of retreating glaciers in mountain ranges worldwide. GLOFs have attracted significant attention amongst scientists and practitioners in the past 2 decades, with particular interest in the physical drivers and mechanisms of GLOF hazard and in socioeconomic and other human-related developments that affect vulnerabilities to GLOF events. This increased research focus on GLOFs is reflected in the gradually increasing number of papers published annually. This study offers an overview of recent GLOF research by analysing 594 peer-reviewed GLOF studies published between 2017 and 2021 (Web of Science and Scopus databases), reviewing the content and geographical focus as well as other characteristics of GLOF studies. This review is complemented with perspectives from the first GLOF conference (7-9 July 2021, online) where a global GLOF research community of major mountain regions gathered to discuss the current state of the art of integrated GLOF research. Therefore, representatives from 17 countries identified and elaborated trends and challenges and proposed possible ways forward to navigate future GLOF research, in four thematic areas: (i) understanding GLOFs - timing and processes; (ii) modelling GLOFs and GLOF process chains; (iii) GLOF risk management, prevention and warning; and (iv) human dimensions of GLOFs and GLOF attribution to climate change.Fil: Emmer, Adam. University of Graz; AustriaFil: Allen, Simon K.. Universitat Zurich; Suiza. Universidad de Ginebra; SuizaFil: Carey, Mark. University of Oregon; Estados UnidosFil: Frey, Holger. Universitat Zurich; SuizaFil: Huggel, Christian. Universitat Zurich; SuizaFil: Korup, Oliver. Universitat Potsdam; AlemaniaFil: Mergili, Martin. University of Graz; AustriaFil: Sattar, Ashim. Universitat Zurich; SuizaFil: Veh, Georg. Universitat Potsdam; AlemaniaFil: Chen, Thomas Y.. Columbia University; Estados UnidosFil: Cook, Simon J.. University Of Dundee; Reino Unido. Unesco. Centre For Water Law, Policy And Science; Reino UnidoFil: Correas Gonzalez, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Das, Soumik. Jawaharlal Nehru University; IndiaFil: Diaz Moreno, Alejandro. Reynolds International Ltd; Reino UnidoFil: Drenkhan, Fabian. Pontificia Universidad Católica de Perú; PerúFil: Fischer, Melanie. Universitat Potsdam; AlemaniaFil: Immerzeel, Walter W.. Utrecht University; Países BajosFil: Izagirre, Eñaut. Universidad del País Vasco; EspañaFil: Joshi, Ramesh Chandra. Kumaun University India; IndiaFil: Kougkoulos, Ioannis. American College Of Greece; GreciaFil: Kuyakanon Knapp, Riamsara. University of Oslo; Noruega. University of Cambridge; Estados UnidosFil: Li, Dongfeng. National University Of Singapore; SingapurFil: Majeed, Ulfat. University Of Kashmir; IndiaFil: Matti, Stephanie. Haskoli Islands; IslandiaFil: Moulton, Holly. University of Oregon; Estados UnidosFil: Nick, Faezeh. Utrecht University; Países BajosFil: Piroton, Valentine. Université de Liège; BélgicaFil: Rashid, Irfan. University Of Kashmir; IndiaFil: Reza, Masoom. Kumaun University India; IndiaFil: Ribeiro De Figueiredo, Anderson. Universidade Federal do Rio Grande do Sul; BrasilFil: Riveros, Christian. Instituto Nacional de Investigación En Glaciares y Ecosistemas de Montaña; PerúFil: Shrestha, Finu. International Centre For Integrated Mountain Development Nepal; NepalFil: Shrestha, Milan. Arizona State University; Estados UnidosFil: Steiner, Jakob. International Centre For Integrated Mountain Development Nepal; NepalFil: Walker-Crawford, Noah. Colegio Universitario de Londres; Reino UnidoFil: Wood, Joanne L.. University of Exeter; Reino UnidoFil: Yde, Jacob C.. Western Norway University Of Applied Sciences; Suiz

In the shadow of global change: towards integrated and adaptive water resources management in the Andes of Peru

In the Tropical Andes of Peru and adjacent lowlands, human livelihoods are exposed to strong changes in hydroclimatic and socioeconomic patterns. On the one hand, climate change impacts are particularly visible by means of glacier retreat and growth of glacier lakes. With decreasing ice masses in highly glacierized catchments, river discharge probably diminishes and its streamflow variability increases. On the other hand, growing energy demand promotes extensions of hydropower plants and thus a major need to rely on a predictable minimum discharge during the whole year. Additionally, the expansion of irrigated agriculture and population growth exert new pressures in the catchments. The antagonistic situation of successively depleting water supply and growing water demand put at risk future water availability.This study analyzes the state of the art of water supply in the Santa (Ancash, La Libertad) and Vilcanota (Cusco) river catchments. The water balance in both catchments is embedded in the framework of Integrated Water Resources Management and the new Water Resources Law. Multiple water conflicts which prevail in Peru, make visible the need for a water resources governance with pathways towards more participative, secure and sustainable water management. Intertwined and complex hydroclimatic and socioeconomic processes with high uncertainty in the Andes of Peru could be tackled with Adaptive Water Management in the future.En los Andes Tropicales del Perú y regiones adyacentes aguas abajo, la subsistencia humana está expuesta a fuertes cambios en los patrones hidroclimáticos y socioeconómicos. Por un lado, los impactos del cambio climático son particularmente visibles a través del retroceso glaciar y crecimiento de lagunas glaciares. Conforme se va reduciendo la masa de hielo en cuencas altamente glaciadas, el caudal de río probablemente decrecerá y su variabilidad aumentará. Por otro lado, la creciente demanda de energía promueve la extensión de centrales hidroeléctricas y por ende una mayor necesidad de contar con un caudal mínimo predecible durante todo el año. Además, la expansión de la agricultura de riego y el crecimiento poblacional generan nuevas presiones en las cuencas. La situación antagonista de una oferta de agua sucesivamente menor y demanda de agua creciente pone en riesgo la futura disponibilidad de agua.Este estudio analiza el estado del arte de la oferta y demanda de agua en las cuencas de los ríos Santa (Ancash, La Libertad) y Vilcanota (Cusco). Se contextualiza el balance hídrico en ambas cuencas en el marco de la Gestión Integrada de Recursos Hídricos y la nueva Ley de Recursos Hídricos. Múltiples conflictos por el agua que prevalecen en el Perú hacen visible la necesidad de una gobernanza de recursos hídricos con trayectorias hacia una gestión más participativa, segura y sostenible. Procesos hidroclimáticos y socioeconómicos entrelazados y complejos con alto grado de incertidumbre en los Andes del Perú, podrían abordarse mediante una Gestión Adaptativa del Agua en el futuro