Regionalization of rainfall over the Peruvian Pacific slope and coast

Rau, Pedro; Bourrel, Luc; Labat, David; Melo, Pablo; Dewitte, Boris; Frappart, Frédéric; Lavado, Waldo; Felipe-Obando, Oscar

doi:10.1002/joc.4693

Cited by 96 publications

(95 citation statements)

References 48 publications

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“…More recently Salzmann et al (2013) andLavado Casimiro et al (2013) analyzed rainfall trends in the southern Peruvian Andes with newer and denser data sets and were unable to find significant trends over the past 40 years. Instead most of the variability in the data appears to be associated with interannual variability driven by the ENSO phenomenon (Rau et al, 2016).…”

Section: Current State Of Glaciers and Climate Change In The Tropicalmentioning

confidence: 93%

Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead

Vuille

Carey

Huggel

et al. 2018

Earth-Science Reviews

250

213

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Glaciers in the tropical Andes have been retreating for the past several decades, leading to a temporary increase in dry season water supply downstream. Projected future glacier shrinkage, however, will lead to a long-term reduction in dry season river discharge from glacierized catchments. This glacier retreat is closely related to the observed increase in high-elevation, surface air temperature in the region. Future projections using a simple freezing level height-equilibrium-line altitude scaling approach suggest that glaciers in the inner tropics, such as Antizana in Ecuador, may be most vulnerable to future warming while glaciers in the more arid outer tropics, such as Zongo in Bolivia, may persist, albeit in a smaller size, throughout the 21st century regardless of emission scenario. Nonetheless many uncertainties persist, most notably problems with accurate snowfall measurements in the glacier accumulation zone, uncertainties in establishing accurate thickness measurements on glaciers, unknown future changes associated with local-scale circulation and cloud cover affecting glacier energy balance, the role of aerosols and in particular black carbon deposition on Andean glaciers, and the role of groundwater and aquifers interacting with glacier meltwater.The reduction in water supply for export-oriented agriculture, mining, hydropower production and human consumption are the most commonly discussed concerns associated with glacier retreat, but many other aspects including glacial hazards, tourism and recreation, and ecosystem integrity are also affected by glacier retreat. Social and political problems surrounding water allocation for subsistence farming have led to conflicts due to lack of adequate water governance. Local water management practices in many regions reflect cultural belief systems, perceptions and spiritual values and glacier retreat in some places is seen as a threat to these local livelihoods.Comprehensive adaptation strategies, if they are to be successful, therefore need to consider science, policy, culture and practice, and involve local populations. Planning needs to be based not only on future scenarios derived from physically-based numerical models, but must also consider societal needs, economic agendas, political conflicts, socioeconomic inequality and cultural values. This review elaborates on the need for adaptation as well as the challenges and constraints many adaptation projects are faced with, and lays out future directions where opportunities exist to develop successful, culturally acceptable and sustainable adaptation strategies.

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Section: Current State Of Glaciers and Climate Change In The Tropicalmentioning

confidence: 93%

Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead

Vuille

Carey

Huggel

et al. 2018

Earth-Science Reviews

250

213

View full text Add to dashboard Cite

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“…In Peru, the enhanced coastal and reduced Andean/ Amazonian rainfall are associated with surface warming in the eastern and central equatorial Pacific, respectively, which can both occur, with varying relative magnitudes, during El Niño or (with approximately the opposite sign) during La Niña (Lagos et al, 2008;Lavado et al, 2013;Rau et al, 2017). We should note that the Atlantic SST variability also plays a key role in modulating the South American climate such as over the Amazon region on several timescales (Espinoza et al, 2011;Marengo and Espinoza, 2016;Jiménez-Muñoz et al, 2016).…”

mentioning

confidence: 90%

Impacts of different ENSO flavors and tropical Pacific convection variability (ITCZ, SPCZ) on austral summer rainfall in South America, with a focus on Peru

Sulca

Takahashi

Espinoza

et al. 2017

Intl Journal of Climatology

132

128

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El Niño in the eastern and central Pacific has different impacts on the rainfall of South America, and the atmospheric pathways through the South Pacific Convergence Zone (SPCZ) and Inter-Tropical Convergence Zone (ITCZ) are poorly understood. To address this, we performed linear regression analysis of E (eastern Pacific) and C (central Pacific) indices of sea surface temperature (SST), as well as precipitation indices for the SPCZ and ITCZ, with gridded precipitation and reanalysis data sets during the austral summer (December-February) for the 1980-2016 period. Positive C induces dry anomalies along the tropical Andes and northern South America (NSA), while wet anomalies prevail over southeastern South America (SESA). Moreover, it produces wet conditions in the northwestern Peruvian Amazon. In contrast, positive E enhances wet conditions along the coasts of Ecuador and northern Peru associated with the southward displacement of the eastern Pacific ITCZ and induces dry conditions in Altiplano, Amazon basin, and northeastern Brazil (NEB). Both El Niño Southern Oscillation (ENSO) indices are associated with weakened upper-level easterly flow over Peru, but it is more restricted to the central and southern Peruvian Andes with positive E. Both SPCZ indices, the zonal position of the SPCZ and its latitudinal displacement, suppress rainfall along western Peruvian Andes when are positive, but the latter also inhibits rainfall over the Bolivian Altiplano. They are also linked to upper-level westerly wind anomalies overall of Peru, but these anomalies do not extend as far south in the first. The southward displacement of the eastern Pacific ITCZ also induces wet anomalies in SESA while dry anomalies prevail over NEB, the western Amazon basin, and Bolivia. Oppositely, the southward displacement of the central Pacific ITCZ induces dry anomalies in NEB and along the northern coast of Peru; while wet anomalies occur mainly in eastern Brazil, Paraguay, and Bolivia through an enhancement of the low level jet.

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“…A careful quality check of these data was previously performed. Monthly precipitation, temperature, and streamflow data were homogenized and validated according to Bourrel et al (); Rau et al (); Rau et al (). Precipitation and temperature data were interpolated to a 5 × 5 km grid using inverse distance weighting interpolation and considering altitudinal gradients.…”

Section: Study Area and Datamentioning

confidence: 99%

Assessing multidecadal runoff (1970–2010) using regional hydrological modelling under data and water scarcity conditions in Peruvian Pacific catchments

Rau

Bourrel

Labat

et al. 2018

Hydrological Processes

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In a context of water scarcity in Peruvian Pacific catchments as a crucial issue for Peru, added to the paucity of data availability, we propose a methodology that provides new perspectives for freshwater availability estimation as a base reference for unimpaired conditions. Under those considerations, a regional discharge of 709 m3/s to the Pacific Ocean is estimated with a significant increasing trend of about 43 m3/s per decade over the 1970–2010 period. To represent the multidecadal behaviour of freshwater runoff along the region, a regional runoff analysis is proposed based on hydrological modelling at annual and monthly time step for unimpaired conditions over the whole 1970–2010 period. Differential Split‐Sample Tests are used to assess the hydrological modelling robustness of the GR1A and GR2M conceptual lumped models, showing a satisfactory transposability from dry to wet years inside the thresholds defined for Nash–Sutcliffe and bias criteria. This allowed relating physical catchment characteristics with calibrated and validated model parameters, thus offering a regional perspective for dryland conditions in the study area (e.g., the anticlockwise hysteresis relationship found for seasonal precipitation–runoff relationship) as well as the impacts of climate variability and catchment characteristics.

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Regionalization of rainfall over the Peruvian Pacific slope and coast

Cited by 96 publications

References 48 publications

Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead

Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead

Impacts of different ENSO flavors and tropical Pacific convection variability (ITCZ, SPCZ) on austral summer rainfall in South America, with a focus on Peru

Assessing multidecadal runoff (1970–2010) using regional hydrological modelling under data and water scarcity conditions in Peruvian Pacific catchments

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