Browsing by Autor "Josyane Ronchail"

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Hydroclimatology of the Upper Madeira River basin: spatio-temporal variability and trends
(Taylor & Francis, 2017) Jorge Molina‐Carpio; Jhan Carlo Espinoza; Philippe Vauchel; Josyane Ronchail; Beatriz Emma Gutierrez Caloir; Jean‐Loup Guyot; Luis Noriega
International audience
Hydrologie et production agricole dans le nord-ouest de l’Amazonie
(Association de Geographes Francais, 2016) Josyane Ronchail; Tatiana Schor; Jhan Carlo Espinoza; Manon Sabot; Heitor Pinheiro; Percy Gomez Davila; Guillaume Drapeau; Véronique Michot; Naziano Filizola; Jean-Loup Guyot
En « Amazonie des rivières », la période de basses eaux permet la mise en culture de vastes zones exondées et fertiles sur les berges des rivières et dans les plaines d’inondation. La variabilité des extrêmes hydrologiques et celle de la structure du cycle de décrue, facteurs réputés importants pour la qualité des récoltes sont explorés à la station fluviométrique de Tamshiyacu sur le fleuve Amazonas. Le riz, culture rentable dans cette région, est notre référence. Les résultats ne présentent pas les liens supposés entre résultats agricoles et durée de la saison de basses eaux ou vitesse de remontée des eaux. Néanmoins, ils montrent la baisse des étiages, l’allongement de la durée de décrue en relation avec un retard de la montée des eaux et une accélération de la remontée des eaux pendant la période 1985-2015.
Inundations in the Mamoré basin (south-western Amazon—Bolivia) and sea-surface temperature in the Pacific and Atlantic Oceans
(Elsevier BV, 2004) Josyane Ronchail; Luc Bourrel; Gérard Cochonneau; Philippe Vauchel; Luis Alejandro Phillips Pedriel; Annibal Castro; Jean‐Loup Guyot; Eurides de Oliveira
Recent changes in the dry-to-wet transition season in the Andean Altiplano and related atmospheric circulation patterns (1981–2022)
(Springer Science+Business Media, 2025) Pierina Milla; Jhan Carlo Espinoza; Ricardo A. Gutiérrez; Jorge Molina‐Carpio; Josyane Ronchail; Daniel Espinoza‐Romero; Clémentine Junquas
Regional hydro-climatic changes in the Southern Amazon Basin (Upper Madeira Basin) during the 1982–2017 period
(Elsevier BV, 2019) Jhan Carlo Espinoza; Anna A. Sörensson; Josyane Ronchail; Jorge Molina‐Carpio; Hans Segura; Omar Gutierrez‐Cori; Romina Ruscica; Thomas Condom; Sly Wongchuig
Regionalization of rainfall in the upper Madeira basin based on interannual and decadal variability: A multi‐seasonal approach
(Wiley, 2023) Jorge Molina‐Carpio; Irma Ayes Rivera; Daniel Espinoza‐Romero; Wilmar L. Cerón; Jhan Carlo Espinoza; Josyane Ronchail
Abstract Identifying rainfall regions associated with specific modes of variability is of practical interest for water resources management, seasonal forecasting, and mitigation of weather‐related risks. This study aims to identify homogeneous rainfall regions within the ~1 million km 2 Upper Madeira River basin—southwestern Amazon—by their interannual and decadal variability and relates this variability to ocean indices. An observed dataset of 146 ground‐based rainfall stations, distributed throughout the Andes and the Amazon, and homogenized at the monthly time‐step for the period 1980–2016, was used for the analysis. With no spatial constraints, hierarchical cluster analysis and principal component analysis (PCA) optimally grouped stations into 10 rainfall homogenous regions. The value of the regionalization for interpreting the rainfall variability was evaluated by relating the seasonal rainfall time series of the regions with ocean indices. Then, by applying PCA to seasonal rainfall series and linking the principal components to sea surface temperature and ocean indices, an insight into the main large‐scale drivers of the rainfall spatio‐temporal variability in this basin at interannual and decadal scales is provided. This analysis identified differences in the year‐round influences of the tropical Pacific and/or Atlantic oceans on the 10 homogenous regions.
The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient
(IOP Publishing, 2014) Jhan Carlo Espinoza; José A. Marengo; Josyane Ronchail; Jorge Molina‐Carpio; Luís Noriega Flores; Jean‐Loup Guyot
Unprecedented wet conditions are reported in the 2014 summer (December-March) in Southwestern Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m 3 s -1 ) at Porto Velho and 380% (25 000 m 3 s -1 ) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Nia and/or warmer than normal tropical South Atlantic, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South Atlantic. Our results suggest that the tropical and subtropical South Atlantic SST gradient is a main driver for moisture transport from the Atlantic toward south-western Amazon, and this became exceptionally intense during summer of 2014.