Raúl Espinoza Villar

Raúl Espinoza Villar
Universidad Nacional Agraria La Molina · Department of Territorial Management and Construction

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66
Publications
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Introduction
Raúl Espinoza Villar currently works at the Departamento Académico de Física Interdisciplinaria, Geophysical Institute of Peru (IGP). Raúl does research in Hydrology and Remote Sensing. Their current project is 'AQUASENSE'.

Publications

Publications (66)
Article
Full-text available
The fast retreat of the tropical Andean glaciers (TAGs) is considered an important indicator of climate change impact on the tropics, since the TAGs provide resources to highly vulnerable mountain populations. This study aims to reconstruct the glacier coverage of the TAGs, using Landsat time-series images from 1985 to 2020, by digitally processing...
Article
Full-text available
As the largest river basin on Earth, the Amazon is of major importance to the world's climate and water resources. Over the past decades, advances in satellite-based remote sensing (RS) have brought our understanding of its terrestrial water cycle and the associated hydrological processes to a new era. Here, we review major studies and the various...
Article
Full-text available
The Madeira River rises in the Andes, draining the southwestern Amazon basin and contributing up to 50% of the Amazon River sediment load. The Porto Velho station monitors the Upper Madeira basin and is located just downstream of the Jirau and Santo Antonio hydropower dams. At this station, decreasing trend (p<0.10) of the surface suspended sedimen...
Preprint
Full-text available
As the largest river basin on Earth, the Amazon is of major importance to the world's climate and water resources. Over the past decades, advances in satellite-based remote sensing (RS) have brought our understanding of its terrestrial water cycle and the associated hydrological processes to a new era. Here, we review major studies and the various...
Article
Full-text available
During the latest decades, the Amazon has experienced a great loss of vegetation cover, in many cases as a direct consequence of wildfires, which became a problem at local, national, and global scales, leading to economic, social, and environmental impacts. Hence, this study is committed to developing a routine for monitoring fires in the vegetatio...
Article
Esta investigación propone un Índice de Bofedal (IB) para identificar los bofedales, ubicados sobre los 3800 ms.n.m. La propuesta del IB es un resumen de la tesis de maestría de Garcia Dulanto, (2018) y se fundamenta en dos métodos: el primero basado en la clasicación Linear Spectral Unmixing queemplea firmas espectrales seleccionadas de elementos...
Article
Full-text available
High-altitude cushion peatlands contain important records for high-resolution palaeoenvironmental studies, due to their high carbon accumulation rates and sensitivity to climatic changes. In this study, we present the paleoenvironmental history for the last 2 500 years based on the study of APA01 core, located in the headwaters of the Cachi river b...
Article
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The biodiversity and productivity of the Amazon floodplain depend on nutrients and organic matter transported with suspended sediments. Nevertheless, there are still fundamental unknowns about how hydrological and rainfall variability influence sediment flux in the Amazon River. To address this gap, we analyzed 3069 sediment samples collected every...
Article
Full-text available
Fluvial sediment dynamics plays a key role in the Amazonian environment, with most of the sediments originating in the Andes. The Madeira River, the second largest tributary of the Amazon River, contributes up to 50% of its sediment discharge to the Atlantic Ocean, most of it provided by the Andean part of the Madeira basin, in particular the Beni...
Chapter
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“Water pollution in Peru is as old as the existence of cities, because rivers and seas have served and continue to serve as final disposal points for sewage” (ONERN, 1985).
Article
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Because increasing climatic variability and anthropic pressures have affected the sediment dynamics of large tropical rivers, long-term sediment concentration series have become crucial for understanding the related socioeconomic and environmental impacts. For operational and cost rationalization purposes, index concentrations are often sampled in...
Article
In this study, we report on the assessment of elevation-dependent warming processes in the Andean region between 7 °S and 20 °S, using Land Surface Temperature (LST). Remotely sensed LST data were obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor in an 8-day composite, at a 1 km resolution, and from 2000 to 2017 during aust...
Article
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Los glaciares andinos son reservas y fuentes de agua dulce para poblaciones cuenca abajo, además son excelentes indicadores del clima y se encuentran en un proceso de retroceso glacial, lo cual puede traer grandes problemas en la disponibilidad del recurso hídrico. El objetivo de este estudio es analizar las tendencias de las extensiones superficia...
Article
Full-text available
The Madeira River is the second largest Amazon tributary, contributing up to 50% of the Amazon River’s sediment load. The Madeira has significant hydropower potential, which has started to be used by the Madeira Hydroelectric Complex (MHC), with two large dams along the middle stretch of the river. In this study, fine suspended sediment concentrati...
Article
Full-text available
The interactions between climate and land-use change are dictating the distribution of flora and fauna and reshuffling biotic community composition around the world. Tropical mountains are particularly sensitive because they often have a high human population density, a long history of agriculture, range-restricted species, and high-beta diversity...
Article
Because increasing climatic variability and anthropic pressures have affected the sediment dynamics of large tropical rivers, long-term sediment concentration series have become crucial for understanding the related socio-economic and environmental impacts. For operational and cost rationalization purposes, index concentrations are often sampled in...
Article
In this study, we used moderate resolution imaging spectroradiometer (MODIS) satellite images to quantify the sedimentation processes in a cascade of six hydropower dams along a 700-km transect in the Paranapanema River in Brazil. Turbidity field measurement acquired over 10 years were used to calibrate a turbidity retrieval algorithm based on MODI...
Conference Paper
Full-text available
The São Francisco River basin has undergone significant changes in soil use and land occupation, which has modified the sedimentation dynamics of the basin. The National Water Agency of Brazil (ANA) performs satellite hydrological monitoring in several rivers and reservoirs in the country. The aim of this study is to evaluate the flow of sediment i...
Article
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The Amazon River sediment discharge has been estimated at between 600 and 1200 Mt/year, of which more than 50% comes from the Solimões River. Because of the area's inaccessibility, few studies have examined the sediment discharge spatial and temporal pattern in the upper Solimões region. In this study, we use MODIS satellite images to retrieve and...
Article
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We investigated the relationships between inherent and apparent optical properties (IOP and AOP, respectively) and suspended sediment concentrations (SSC) in the main Amazonian river waters. In situ measurements of SSC, remote sensing reflectance (Rrs), the diffuse light attenuation coefficient (Kd) and the total and non-algal particle (NAP) absorp...
Article
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In 2015, an emergency state was declared in Bolivia when Poopó Lake dried up. Climate variability and the increasing need for water are potential factors responsible for this situation. Because field data are missing over the region, no statements are possible about the influence of mentioned factors. This study is a preliminary step toward the und...
Article
Full-text available
Se diseñó una metodología para identificar y cuantificar la extensión de los bofedales de puna de la cabecera de cuenca del río Chillón, ubicados sobre los 3800 msnm y se eligió un bofedal piloto. Se procesó información de los sensores Landsat TM, ETM+ y OLI de los años 1986 al 2015, una imagen por año. Las imágenes correspondían a la fecha más pró...
Conference Paper
The monitoring of water quality has become of great importance to evaluate and understand the consequences of human activities on aquatic ecosystems. Remote sensing is being used increasingly for the monitoring of water quality parameters in rivers and lakes. The objective of this work is to understand the variability of water optical properties in...
Conference Paper
Full-text available
The objective of this work was to compare the radiometric accuracy of SPOT 5 Take 5 and Landsat 8 OLI surface reflectance products and its efficacy in to estimate the Suspended Solids Concentration (SSC) in Paranoá Lake, Brasília-DF, Brazil. In situ radiometry (R rs) by Trios hyperspectral spectroradiometers and water samples for SSC were collected...
Article
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Accurately measuring sediment flux in large rivers remains a challenge due to the spatial and temporal cross-sectional variability of suspended sediment concentrations in conjunction with sampling procedures that fail to accurately quantify these differences. This study presents a field campaign methodology that can be used to improve the measureme...
Presentation
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Le Service National d’Observation HYBAM sur les grands fleuves du bassin Atlantique : un dispositif de recherche en coopération Sud-Sud-Nord
Research
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Considerando a potencialidade dos dados MODIS, com as particularidades ou limitações (como a cobertura de nuvens e a baixa resolução espacial) imposto pela forma como o sensor registra os dados, este trabalho mostra uma perspectiva sobre a disponibilidade, desempenho e qualidade de dados MODIS na região da Reservatório da UHE de Santo Antônio (a mo...
Article
Full-text available
Satellite images can now be used to assess river sediment discharge, and systematic studies over rivers and lakes are required to support such applications and document the variability of inland water optical properties at the watershed scale. The optical properties of the Amazon Basin waters were analyzed from in situ measurements of the remote se...
Article
Full-text available
Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passing through the Amazon Basin. Denudation rates in th...
Chapter
Full-text available
Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passingthrough the Amazon Basin. Denudation rates in the...
Chapter
Full-text available
HYBAM: an observatory to measure the impact of climate change on erosion and sediment flows in the Andean Amazon region. The Amazon basin is the largest basin in the world. The implementation of the HYBAM observatory, which has installed a large network of hydrological stations located from the Andean foothills down to the Atlantic Ocean, allows si...
Conference Paper
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INTRODUÇÃO: O uso de satélites para estimar variáveis hidrológicas têm-se tornado frequente, sobretudo em bacias de grandes rios como a bacia amazônica, onde o monitoramento é um desafio ao longo do espaço e do tempo. A estimativa da concentração de sedimentos em suspensão (CSS) em rios amazônicos é um exemplo dessa dificuldade, e por isso tem moti...
Presentation
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Measuring and modeling vertical gradients of suspended sediments in the Amazon River
Article
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This study presents the monitoring of the sediment discharge from the Indaia River into the Tres Marias reservoir, based on the use of satellite images. A 12-year time series of MODIS 8-day image composites (Terra and Aqua on-board sensors) was used in this study. Estimates of the water surface reflectance were calculated using the algorithm MOD3R....
Article
Full-text available
Objetivou-se, neste trabalho, monitorar o fluxo de entrada de sedimentos no braço do Rio Indaiá no reservatório de Três Marias, MG, com base em dados das imagens de satélites. Foram adquiridas séries temporais de 12 anos das imagens MODIS (Terra e Aqua), compostas de 8 dias. Estimativas de reflectância da superfície foram calculadas usando-se o alg...
Presentation
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5ta reunión científica del ORE HYBAM - Hidroclimatologia y biogeoquimica de las aguas, de los Andes a la Amazonia
Presentation
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5ta reunión científica del ORE HYBAM - Hidroclimatologia y biogeoquimica de las aguas, de los Andes a la Amazonia
Presentation
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Determinación de la concentración de sedimentos en suspensión finos a través de mecanismos ópticos: aplicación del modelo de Rouse
Presentation
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Journée scientifique de l’Observatoire HYBAM
Presentation
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Monitoreo del transporte de sedimentos en los ríos amazónicos usando datos satelitales MODIS
Article
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In this work we document and analyze the hydrological annual cycles characterized by a rapid transition between low and high flows in the Amazonas River (Peruvian Amazon) and we show how these events, which may impact vulnerable riverside residents, are related to regional climate variability. Our analysis is based on comprehensive discharge, rainf...
Presentation
Full-text available
Estudo dos processos de transporte sedimentar no Rio Madeira usando sensores remotos
Presentation
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4ta reunión científica del ORE HYBAM - Hidrología y geodinámica actual de las cuencas sudamericanas
Presentation
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Se puede aplicar la turbiedad como herramienta de medida de MES en la cuenca Amazonica ?
Presentation
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Towards operational monitoring of sediment transport in the Amazon basin from space