Browsing by Author "Armijos Cardenas, Elisa Natalia"
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Item Restricted A reassessment of the suspended sediment load in the Madeira River basin from the Andes of Peru and Bolivia to the Amazon River in Brazil, based on 10 years of data from the HYBAM monitoring programme(Elsevier, 2017-10) Vauchel, Phillippe; Santini, William; Guyot, Jean Loup; Moquet, Jean Sébastien; Martínez, Jean Michel; Espinoza, Jhan Carlo; Baby, Patrice; Fuertes, Oscar; Noriega, Luis; Puita, Oscar; Sondag, Francis; Fraizy, Pascal; Armijos Cardenas, Elisa Natalia; Cochonneau, Gérard; Timouk, Franck; Olivera, Eurides de; Filizola, Naziano; Molina, Jorge; Ronchail, JosyaneThe Madeira River is the second largest tributary of the Amazon River. It contributes approximately 13% of the Amazon River flow and it may contribute up to 50% of its sediment discharge to the Atlantic Ocean. Until now, the suspended sediment load of the Madeira River was not well known and was estimated in a broad range from 240 to 715 Mt yr⁻¹. Since 2002, the HYBAM international network developed a new monitoring programme specially designed to provide more reliable data than in previous intents. It is based on the continuous monitoring of a set of 11 gauging stations in the Madeira River watershed from the Andes piedmont to the confluence with the Amazon River, and discrete sampling of the suspended sediment concentration every 7 or 10 days. This paper presents the results of the suspended sediment data obtained in the Madeira drainage basin during 2002–2011. The Madeira River suspended sediment load is estimated at 430 Mt yr⁻¹ near its confluence with the Amazon River. The average production of the Madeira River Andean catchment is estimated at 640 Mt yr⁻¹ (±30%), the corresponding sediment yield for the Andes is estimated at 3000 t km⁻² yr⁻¹ (±30%), and the average denudation rate is estimated at 1.20 mm yr⁻¹ (±30%). Contrary to previous results that had mentioned high sedimentation rates in the Beni River floodplain, we detected no measurable sedimentation process in this part of the basin. On the Mamoré River basin, we observed heavy sediment deposition of approximately 210 Mt yr⁻¹ that seem to confirm previous studies. But while these studies mentioned heavy sedimentation in the floodplain, we showed that sediment deposition occurred mainly in the Andean piedmont and immediate foreland in rivers (Parapeti, Grande, Pirai, Yapacani, Chimoré, Chaparé, Secure, Maniqui) with discharges that are not sufficiently large to transport their sediment load downstream in the lowlands.Item Restricted Climate control on silicate weathering and physical erosion rates in young orogenic belts: Case study along a runoff gradient in Pacific and Amazonian Andean basins based on SNO-HYBAM Monitoring Program data(EGU General Assembly, 2017-04) Moquet, Jean Sébastien; Guyot, Jean-Loup; Viers, Jérôme; Crave, Alain; Morera Julca, Sergio Byron; Rau, Pedro; Armijos Cardenas, Elisa Natalia; Lagane, Christelle; Lavado Casimiro, Waldo Sven; Pombosa, Rodrigo; Fraizy, Pascal; Santini, William; Timouk, Franck; Vauchel, Philippe; Martinez, Jean-MichelAt the global scale and on geological time scales, mechanical erosion and chemical weathering budgets are linked. Together, these processes contribute to the formation and the degradation of the Earth's critical zone and to the biogeochemical cycles of elements. In young orogenic belts, climate and tectonic subsidence control together the rate of these matter balance budget and their relationships. The climate gradient observed along the Andean basin in both the Pacific and the Atlantic slopes offers the opportunity to explore the role of the climate variability on the erosion and weathering budgets and on their reciprocal relationships. Based on the SNO-HYBAM Monitoring Program database (Geodynamical, hydrological and Biogeochemical control of erosion/weathering and material transport in the Amazon, Orinoco and Congo basins), we explore the relationship between climate, the lithology, silicate weathering rates and physical erosion rates along a runoff gradient in Andean basins of the Amazon River (13 gauging stations) and Pacific drainage rivers (5 gauging stations). No homogenous relationship between erosion rates (E) and chemical weathering rate (W) is observed over the monitored basins. Only the volcanic basins respond to a global relationship defined in the literature while the other basins budget may depend on anthropogenic interferences on erosion/sedimentation budget, a lithology dependence of the W-E relationship parameters or/and on the existence of a threshold in this relationship. The results presented here contribute to better understanding the role of mountains belt formation in the biogeochemical cycles and in particular in the long-term carbon cycle.Your presentation type preference.Item Open Access Decline of fine suspended sediments in the Madeira River Basin (2003–2017)(MDPI, 2019-03-12) Ayes Rivera, Irma; Armijos Cardenas, Elisa Natalia; Espinoza Villar, Raúl Arnaldo; Espinoza, Jhan Carlo; Molina-Carpio, Jorge; Max Ayala, José; Gutierrez Cori, Omar; Martinez, Jean-Michel; Filizola, NazianoThe 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 concentration (FSC) data were assessed downstream of the MHC at the Porto Velho gauging station and at the outlet of each tributary (Beni and Mamoré Rivers, upstream from the MHC), from 2003 to 2017. When comparing the pre-MHC (2003–2008) and post-MHC (2015–2017) periods, a 36% decrease in FSC was observed in the Beni River during the peak months of sediment load (December–March). At Porto Velho, a reduction of 30% was found, which responds to the Upper Madeira Basin and hydroelectric regulation. Concerning water discharge, no significant change occurred, indicating that a lower peak FSC cannot be explained by changes in the peak discharge months. However, lower FSCs are associated with a downward break in the overall time series registered at the outlet of the major sediment supplier—the Beni River—during 2010.Item Open Access Evaluación de los niveles de riesgo de inundación por “repiquetes” en áreas de cultivos ribereños en la cuenca Amazónica peruana: caso de estudio de la ciudad de Tamshiyacu(Instituto Geofísico del Perú, 2023-10) Valenzuela, Jonathan; Figueroa, Manuel; Armijos Cardenas, Elisa Natalia; Espinoza, Jhan Carlo; Wongchuig, Sly; Ramirez-Avila, John J.El proyecto “Origen, frecuencia y magnitud de los repiquetes, su impacto en la agricultura amazónica y en el transporte de sedimentos, utilizando sensoramiento remoto”, financiado por PROCIENCIA, tuvo como objetivo estudiar las características climatológicas e hidrológicas que producen inundaciones repentinas (conocidos como repiquetes) en las riberas de los ríos amazónicos, las cuales afectan la agricultura ribereña. En los meses de vaciante (junio-octubre) se aprovechan las tierras fértiles de las playas que se forman en las riberas del río Amazonas, con cultivos de ciclo corto, siendo el arroz el más importante por su consumo interno e ingreso económico. Utilizando datos de fotogrametría de la orilla izquierda del río Amazonas, frente a la ciudad de Tamshiyacu (ubicada a 50 km aguas arriba de la ciudad de Iquitos), junto con datos batimétricos y la serie de datos de niveles durante el periodo 1996- 2018 del río Amazonas, se logró determinar zonas de riesgo de inundación que afectan los cultivos. Los resultados indican que la zona cultivable está entre las cotas 83.00 y 88.00 m s. n. m. Durante el período de estudio se encontró que 42 de los 73 eventos inundaron parcialmente los cultivos, los cuales marcan su inicio de aumento del nivel del agua por flujo de humedad y precipitación sobre el norte de las cuencas de los ríos Marañón y Ucayali. El riesgo de repiquetes por inundación en vaciante es de 1 repiquete cada 3 años para el rango de elevación entre 85.31 y 87.00 m s. n. m., disponiendo del 31 % del área total. En tanto, la frecuencia de ocurrencia de repiquetes es 0 para el área mayor a 87.01 m s. n. m., teniendo un 43 % de la superficie total. Se determinaron repiquetes extremos en los años 2002 y 2008, los cuales inundaron el 43 % y 25 % de sus áreas disponibles al inicio del evento. […] Al caracterizar los repiquetes y determinar las zonas de riesgo estamos complementando el saber local de los agricultores ribereños y contribuyendo a incrementar su capacidad para reducir el riesgo.Item Open Access Flooding risk of cropland areas by repiquetes in the western Amazon basin: A case study of Peruvian Tamshiyacu City(Elsevier, 2023-06) Valenzuela, Jonathan; Figueroa, Manuel; Armijos Cardenas, Elisa Natalia; Espinoza, Jhan-Carlo; Wongchuig, Sly; Ramirez-Avila, John J.Study región: The western Amazon basin at Tamshiyacu gauging station (near the Iquitos City) hosts floodplain agriculture that can be affected by the sudden reversal in direction of water levels known as “repiquetes” that produce intermittent flooding. Study focus: This study assesses repiquete flooding risk in riparian crop areas based on statistical analyses of repiquete events registered from 1996 to 2018, hydraulic modeling to estimate flooded extension, and assessment of climatological characteristics during the formation of repiquetes. New hydrological insights: Floods (≥ 20 cm) produced by repiquetes in riparian crop areas between 83.00 and 88.00 m above sea level (masl) occur 1.8 times per year. However, not all elevation ranges have the same flooding risk to crops. Terrain elevations between 85.31 and 87.00 masl have a reduced flooding risk of 0.35 per year. Likewise, areas with elevations between 87.00 and 88.00 masl (43% of the total area) were not affected by repiquetes. Extreme repiquetes (study cases of 2002 and 2008) have been influenced by the increase of atmospheric moisture flux convergence and precipitation over both the northern Ucayali and Marañón basins through the six previous days. Flood impacts from the extreme event of 2002 (2008) could have reached 40% (25%) of the available area for agriculture at the initiation of the repiquete.Item Open Access Influencia de la precipitación sobre los flujos de sedimentos en el Amazonas: una síntesis basada en 20 años de monitoreo(Instituto Geofísico del Perú, 2020-04) Armijos Cardenas, Elisa Natalia; Crave, Alain; Espinoza, Jhan Carlo; Filizola, Naziano; Espinoza-Villar, Raúl; Ayes, Irma; Fonseca, Paula; Fraizy, Pascal; Gutierrez, Omar; Vauchel, Philippe; Camenen, Benoit; Martiınez, Jean Michel; Dos Santos, André; Santini, William; Cochonneau, Gérard; Guyot, Jean LoupLa vida en la región amazónica está principalmente relacionada con la estacionalidad del régimen hidrológico fluvial. La riqueza de la biodiversidad y productividad de la llanura de inundación depende de los nutrientes y la materia orgánica que son transportados por los ríos en los sedimentos en suspensión, desde los Andes hacia el océano Atlántico. Sin embargo, poco se conoce sobre la influencia de la variabilidad hidrológica y pluvial en los flujos sedimentarios. Para abordar esta brecha, analizamos 3069 muestras superficiales de agua y sedimentos recolectadas en el centro del río, cada 10 días durante el período 1995-2014, en 6 estaciones ubicadas en el río Amazonas y sus tributarios. Este análisis se ha realizado haciendo una distinción del tamaño de las partículas, sedimentos finos (arcilla y limo) y sedimentos gruesos (arena). Considerando esta distinción, se estimó, por primera vez, que en la llanura amazónica predomina el flujo de sedimento fino con un 60 % y las arenas representan el 40 % complementario. La lluvia tiene una relación con la producción de sedimentos finos, mientras que el caudal rige el transporte de arenas en suspensión. Adicionalmente, este trabajo presenta el tiempo de respuesta entre la lluvia y el caudal. Los resultados obtenidos en este estudio son una contribución importante a la dinámica biológica y geomorfológica en la cuenca del Amazonas.Item Open Access MoSARD (Monitoreo de los Sedimentos ante el Riesgo y Desastres)(Instituto Geofísico del Perú, 2018-12) Morera Julca, Sergio Byron; Armijos Cardenas, Elisa Natalia; Espinoza Villar, Raúl ArnaldoEl proyecto MoSARD, es una iniciativa de los doctores Sergio Morera, Elisa Armijos y Raúl Espinoza, investigadores científicos de la Subdirección de Ciencias de la Atmósfera e Hidrósfera del Instituto Geofísico del Perú (IGP), que tiene como objetivo continuar con estudios que contribuyan con el entendimiento de los procesos de transporte y la dinámica del ciclo de sedimentos ya sea en laderas o sistemas hídricos. Generando información inédita, así como estudios técnico-científicos que faciliten la gestión-mitigación de las modificaciones abruptas en los ecosistemas Andinos, zonas de piedemonte, costero y la llanura amazónica. El proyecto está vinculado con instituciones gubernamentales, proyectos nacionales e internacionales, así como centros académicos; para en conjunto actuar de manera eficiente frente a la presencia de eventos de riesgos climáticos y/o geológicos que amenazan constantemente a nuestras ciudades. De esta manera se busca disminuir el impacto de los riesgos ambientales, evitar pérdidas de infraestructuras hidráulicas y vías de comunicación e incrementar el bienestar de la población peruana.Item Open Access On the relationship between reversal of the river stage (repiquetes), rainfall and low-level wind regimes over the western Amazon basin(Elsevier, 2020-12) Figueroa, Manuel; Armijos Cardenas, Elisa Natalia; Espinoza, Jhan Carlo; Ronchail, Josyane; Fraizy, PascalStudy region: The Amazonas River and its tributaries (Peru), where riparian farmers face hydro-logical events that put their lowland crops at high risk of production loss during the flood recession period. Study focus: This paper analyzes the hydro-meteorological mechanisms over the Andes-Amazon basins that produce “repiquetes”, which are sudden reversals of the river stage. They are defined and characterized for the period 1996–2018 by using river stage data from three hy-drological gauging stations for the Amazonas, Mara ̃n ́on and Ucayali Rivers. Daily rainfall and low-level winds depict the large-scale atmospheric patterns associated with repiquetes. New hydrological insights: Among 73 significant repiquetes (reversal ≥20 cm) observed in the Amazonas River, 64 % were preceded by repiquetes only in the Mara ̃n ́on River, 5 % by repiquetes only in the Ucayali River, 21 % by repiquetes in both rivers and 10 % was only registered in the Amazonas River without upstream precursor. These results show that repiquetes in the Mara ̃n ́on River are the primary precursors of repiquetes in the Amazonas River. Most repiquetes are associated with abundant rainfall over the Peruvian and Ecuadorian Andes-Amazon transition region related to a remarkable change in the direction of the meridional wind, from north to south, and an easterly flow five to three days before the beginning of a repiquete in the Amazonas River.Item Open Access On the relationship between suspended sediment concentration, rainfall variability and groundwater: an empirical and probabilistic analysis for the Andean Beni River, Bolivia (2003–2016)(MDPI, 2019-11) Ayes Rivera, Irma; Callau Poduje, Ana Claudia; Molina-Carpio, Jorge; Ayala, José Max; Armijos Cardenas, Elisa Natalia; Espinoza-Villar, Raúl; Espinoza, Jhan Carlo; Gutierrez-Cori, Omar; Filizola, NazianoFluvial 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 River. In this study, we assessed the rainfall (R)-surface suspended sediment concentration (SSSC) and discharge (Q)-SSSC relationship at the Rurrenabaque station (200 m a.s.l.) in the Beni Andean piedmont (Bolivia). We started by showing how the R and Q relationship varies throughout the hydrological year (September to August), describing a counter-clockwise hysteresis, and went on to evaluate the R–SSSC and Q–SSSC relationships. Although no marked hysteresis is observed in the first case, a clockwise hysteresis is described in the second. In spite of this, the rating curve normally used ( SSSC=aQb ) shows a satisfactory R² = 0.73 (p < 0.05). With regard to water discharge components, a linear function relates the direct surface flow Qs–SSSC, and a hysteresis is observed in the relationship between the base flow Qb and SSSC. A higher base flow index (Qb/Q) is related to lower SSSC and vice versa. This article highlights the role of base flow on sediment dynamics and provides a method to analyze it through a seasonal empirical model combining the influence of both Qb and Qs, which could be employed in other watersheds. A probabilistic method to examine the SSSC relationship with R and Q is also proposed.Item Restricted Performance of bedload sediment transport formulas applied to the Lower Minnesota River(American Society of Civil Engineers, 2021-07) Armijos Cardenas, Elisa Natalia; Merten, Gustavo H.; Groten, Joel T.; Ellison, Christopher A.; Lisiecki, Luke U.Despite limitations in reproducing complex bedload sediment transport processes in rivers, formulas have been preferred over collection and analysis of field data due to the high cost and time-consuming nature of bedload discharge measurements. However, the performance of such formulas depends on the hydraulic and sedimentological conditions they attempt to describe. The availability of field measurements provides a unique opportunity to test bedload transport formulas to better guide formula selection. Hydraulic parameters and bedload discharge data from the Lower Minnesota River and two of its tributaries were used to evaluate nine bedload transport formulas using three different indices. The bedload data for the different sites were collected by the United States Geological Survey (USGS) from 2011 through 2014, with bed material varying from very coarse to medium sand. The formulas calculated higher bedload rates than were measured due to a combination of site-specific physical characteristics, including the presence of bed forms (dunes), and sampling uncertainties. Because of the lack of reproducibility of the tested formulas, five power functions, based on the relation between the specific unit power (independent hydraulic variable) and the USGS measured data (dependent variable), were derived as provisional equations to estimate the bedload discharge on the Lower Minnesota River and tributaries.Item Open Access Performance of Regional Climate Model Precipitation Simulations Over the Terrain-Complex Andes-Amazon Transition Region(American Geophysical Union, 2024-01-06) Gutierrez, Ricardo A.; Junquas, Clémentine; Armijos Cardenas, Elisa Natalia; Sörensson, Anna A.; Espinoza, Jhan-CarloRegional climate models (RCMs) are widely used to assess future impacts associated with climate change at regional and local scales. RCMs must represent relevant climate variables in the present-day climate to be considered fit-for-purpose for impact assessment. This condition is particularly difficult to meet over complex regions such as the Andes-Amazon transition region, where the Andean topography and abundance of tropical rainfall regimes remain a challenge for numerical climate models. In this study, we evaluate the ability of 30 regional climate simulations (6 RCMs driven by 10 global climate models) to reproduce historical (1981–2005) rainfall climatology and temporal variability over the Andes-Amazon transition region. We assess spatio-temporal features such as spatial distribution of rainfall, focusing on the orographic effects over the Andes-Amazon “rainfall hotspots” region, and seasonal and interannual precipitation variability. The Eta RCM exhibits the highest spatial correlation (up to 0.6) and accurately reproduces mean annual precipitation and orographic precipitation patterns across the region, while some other RCMs have good performances at specific locations. Most RCMs simulate a wet bias over the highlands, particularly at the eastern Andean summits, as evidenced by the 100%–2,500% overestimations of precipitation in these regions. Annual cycles are well represented by most RCMs, but peak seasons are exaggerated, especially at equatorial locations. No RCM is particularly skillful in reproducing the interannual variability patterns. Results highlight skills and weaknesses of the different regional climate simulations, and can assist in the selection of regional climate simulations for impact studies in the Andes-Amazon transition zone.Item Open Access Rainfall control on Amazon sediment flux: synthesis from 20 years of monitoring(IOP Publishing, 2020-05-14) Armijos Cardenas, Elisa Natalia; Crave, A.; Espinoza, Jhan Carlo; Filizola, N.; Espinoza-Villar, R.; Ayes, I.; Fonseca, P.; Fraizy, P.; Gutierrez, O.; Vauchel, P.; Camenen, B.; Martiınez, J. M.; Dos Santos, A.; Santini, W.; Cochonneau, G.; Guyot, J. L.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 10 days during 1995–2014 at five gauging stations located in the main rivers. We have two distinct fractions of suspended sediments, fine (clay and silt) and coarse (sand), which followed contrasting seasonal and long-term patterns. By taking these dynamics into account, it was estimated, for first time, in the Amazon plain, that the suspended sediment flux separately measured approximately 60% fine and 40% coarse sediment. We find that the fine suspended sediments flux is linked to rainfall and higher coarse suspended sediment flux is related with discharge. Additionally this work presents the time lag between rainfall and discharge, which is related to the upstream area of the gauging. This result is an important contribution to knowledge of biological and geomorphological issues in Amazon basin.Item Open Access Relación entre la reversión de la cota del río (repiquetes), las lluvias y los vientos en niveles bajos sobre el oeste de la cuenca amazónica(Instituto Geofísico del Perú, 2020-10) Figueroa, M.; Armijos Cardenas, Elisa Natalia; Espinoza, J.; Ronchail, J.; Fraizy, P.La agricultura ribereña en épocas de recesión del caudal (junio-octubre) es una de las actividades económicas más importantes de la llanura amazónica. Sin embargo, esta labor se ve afectada por los conocidos “repiquetes”, los cuales son inundaciones repentinas que se desarrollan en plena época de recesión debido a la reversión en el nivel del río. Utilizando datos diarios de nivel del río obtenidos de las reglas limnimétricas de las estaciones localizadas en los ríos Amazonas, Marañón y Ucayali, durante el período 1996-2018; se pudo determinar que de los 73 repiquetes observados en el río Amazonas (reversión ≥ 20 cm), el 64 % de ellos fueron precedidos por repiquetes solo en el río Marañón, y el 5 % fueron repiquetes originados solo en el río Ucayali. El 21 % de los eventos fueron antecedidos por repiquetes en ambos ríos y 10 % no tuvieron precursor aguas arriba. Estos resultados indican que el río Marañón es el principal precursor de los repiquetes originados en el río Amazonas. Analizando la lluvia diaria y vientos en niveles bajos (850 hPa) se puede concluir que los repiquetes registrados en el río Amazonas se originan por las abundantes lluvias en la región de transición Andes-Amazonas entre Perú y Ecuador, las cuales acontecen de tres a cinco días antes del inicio de cada repiquete. Las lluvias precursoras se relacionan con un cambio notable en la dirección del viento meridional, de norte a sur, y a un flujo de humedad hacia el este.Item Open Access Repiquetes: crecidas repentinas que afectan los cultivos de los ribereños amazónicos(Instituto Geofísico del Perú, 2020-02) Figueroa, Manuel; Armijos Cardenas, Elisa Natalia; Espinoza, Jhan Carlo; Pascal, Fraizy; Ronchail, JosyaneUna de las actividades económicas importantes en la llanura amazónica es la agricultura de ciclo corto en los meses de recesión, sin embargo, esta se ve afectada por inundaciones repentinas. Estos eventos identificados por las reversiones en el nivel del río son conocidos localmente como repiquetes y su génesis ha sido poco estudiada. Utilizando los niveles registrados en dos estaciones limnimétricas localizadas en los ríos Marañón y Ucayali, aguas arriba de la confluencia para formar el río Amazonas; se pudo identificar que los repiquetes, ocurridos próximos a la estación de Tamshiyacu (río Amazonas), son producidos principalmente por eventos observados en el río Marañón. El origen de los repiquetes en el río Marañón está relacionado al aporte de las lluvias ocurridas en el norte de la cuenca en los Andes ecuatorianos y peruanos. Estos primeros resultados son un avance para posibles trabajos de predicción que permitan alertar a la población sobre las inundaciones repentinas contribuyendo de esta manera a la mitigación de los daños por pérdidas de cultivos.Item Open Access Simulaciones de la precipitación de verano por modelos climáticos regionales de CORDEX en la zona de transición Andes-Amazonía(Instituto Geofísico del Perú, 2023-02) Gutiérrez, Ricardo A.; Junquas, Clémentine; Armijos Cardenas, Elisa Natalia; Sörensson, A. A.; Espinoza, Jhan-CarloEl presente avance de investigación evalúa el realismo de la climatología histórica (1981-2005) de la precipitación de verano en la zona de transición Andes-Amazonía a partir de las simulaciones del experimento regional coordinado de reducción de escala (CORDEX, por sus siglas en inglés) para Sudamérica. Los resultados preliminares muestran que no habría una relación aparente entre la performance del modelo y la resolución espacial en cuanto a la reproducción de las climatologías de precipitación, cuando se esperaría que los modelos tengan un mejor rendimiento, es decir, reproduzcan mejor las precipitaciones al tener una resolución espacial más alta o más fina. En conclusión, será necesaria la aplicación de modelos regionales de resolución espacial más fina y realizar experimentos de sensibilidad con diferentes parametrizaciones físicas para lograr mejorar el realismo de los patrones espaciales de la precipitación orográfica sobre la región de estudio.Item Restricted Spatio-temporal monitoring of suspended sediments in the Solimões River (2000–2014)(Elsevier, 2018) Espinoza Villar, Raúl Arnaldo; Martínez, Jean-Michel; Armijos Cardenas, Elisa Natalia; Espinoza, Jhan Carlo; Filizola, Naziano; Dos Santos, Andre; Willems, Bram; Fraizy, Pascal; Santini, William; Vauchel, PhilippeThe 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 understand the spatial and temporal behaviour of suspended sediments in the Solimões River from Peru to Brazil. Six virtual suspended sediment gauging stations were created along the Solimões River on a 2050-km-long transect. At each station, field-derived river discharge estimates were available and field-sampling trips were conducted for validation of remote-sensing estimates during different periods of the annual hydrological cycle between 2007 and 2014. At two stations, 10-day surface suspended sediment data were available from the SO-HYBAM monitoring program (881 field SSS samples). MODIS-derived sediment discharge closely matched the field observations, showing a relative RMSE value of 27.3% (0.48 Mtday) overall. Satellite-retrieved annual sediment discharge at the Tamshiyacu (Peru) and Manacapuru (Brazil) stations is estimated at 521 and 825 Mt/year, respectively. While upstream the river presents one main sediment discharge peak during the hydrological cycle, a secondary sediment discharge peak is detected downstream during the declining water levels, which is induced by sediment resuspension from the floodplain, causing a 72% increase on average from June to September.Item Open Access Suspended sediment variability at the Solimões and Negro confluence between May 2013 and February 2014(MDPI, 2018-07) Marinho, Thiago; Filizola, Naziano; Martinez, Jean-Michel; Armijos Cardenas, Elisa Natalia; Nascimento, AndréThis study focuses on the confluence of two major rivers of the world, the Solimões River (white waters) and Negro River (black waters). Surface suspended sediment samples (SSC) and spectroradiometer taken along transverse profiles at 500 m intervals over a distance of 10 km, as well as satellite images (MODIS) during the hydrological year, were used to follow suspended sediment variability. In January and February, the confluence is dominated by white waters from the Solimões River in the two banks, and in June and July in the right bank by black waters from the Negro River and in the left bank by clear waters from the Solimões River. We found that indirect tools, such as reflectance obtained by spectrometer or MODIS images, can be used to determine surface suspended sediments in a contrasting zone.Item Open Access Transporte de sedimentos en el Río Puyango-Tumbes durante el Fenómeno El Niño Costero 2017-Proyecto MoSARD(Instituto Geofísico del Perú, 2019-05) Mendoza, Renzo; Armijos Cardenas, Elisa Natalia; Morera Julca, Sergio Byron; Figueroa, ManuelLa costa peruana es la región que sustenta la mayor actividad económica del país. No obstante, dicha región es altamente afectada por eventos climáticos extremos como el Fenómeno El Niño (FEN). El FEN está asociado a precipitaciones elevadas en el período de enero a marzo en la costa norte del Perú (Woodman. 1997; Woodman y Takahashi, 2014), las cuales incrementan el volumen de agua en los ríos y promueven el arrastre de grandes cantidades de sedimentos. La acumulación de estos sedimentos provoca la colmatación de los ríos haciendo que estos se desborden. Morera et al. (2017), identifican que durante el FEN los flujos sedimentarios en la costa peruana se incrementan en aproximadamente un 60%.