Paulina Vidal-Páez

Ms. Paulina Vidal-Páez

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Journal Article
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AJAlberto Jopia
Alberto Jopia
Francisco ZambranoFrancisco Zambrano
Francisco Zambrano
WPWaldo Pérez-Martínez
Waldo Pérez-Martínez
PVPaulina Vidal-Páez
Paulina Vidal-Páez
JMJulio Molina
Julio Molina
FMFelipe de la Hoz Mardones
Felipe de la Hoz Mardones
For more than ten years, Central Chile has faced drought conditions, which impact crop production and quality, increasing food security risk. Under this scenario, implementing management practices that allow increasing water use efficiency is urgent. The study was carried out on kiwifruit trees, located in the O’Higgins region, Chile for season 2018–2019 and 2019–2020. We evaluate the time-series of nine vegetation indices in the VNIR and SWIR regions derived from Sentinel-2 (A/B) satellites to establish how much variability in the canopy water status there was. Over the study’s site, eleven sensors were installed in five trees, which continuously measured the leaf’s turgor pressure (Yara Water-Sensor). A strong Spearman’s (ρ) correlation between turgor pressure and vegetation indices was obtained, having −0.88 with EVI and −0.81 with GVMI for season 2018–2019, and lower correlation for season 2019–2020, reaching −0.65 with Rededge1 and −0.66 with EVI. However, the NIR range’s indices were influenced by the vegetative development of the crop rather than its water status. The red-edge showed better performance as the vegetative growth did not affect it. It is necessary to expand the study to consider higher variability in kiwifruit’s water conditions and incorporate the sensitivity of different wavelengths.

14 March 2020 in Remote Sensing
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Journal Article
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ADAnalia Delsouc
Analia Delsouc
MBMatias Barber
Matias Barber
AGAudrey Gallaud
Audrey Gallaud
FGFrancisco Grings
Francisco Grings
PVPaulina Vidal-Páez
Paulina Vidal-Páez
IBIdania Coromoto Briceño-de-Urbaneja
Idania Coromoto Briceño-de-Urbaneja
Seasonal changes control the development of salt crust over the Salar de Aguas Calientes Sur located in Andes Highlands, Chile. Precipitations throughout the Altiplanic winter (December to March) and austral winter (June to September) caused ponds to enlarge and surface salt crusts to dissolve driving roughness and dielectric features of the salar surface change over time. A four-year time series backscattering coefficient analysis, obtained by Sentinel 1 and ALOS-2/PALSAR-2 with 10 m of spatial resolution, demonstrated the capability of microwaves to discriminate seasonal patterns illustrated in this paper. Both sensors showed to be sensitive to changes in the surface crust due to weather conditions. Backscattered power gradually increased during the driest months as the rough salt crusts develop and decreased rapidly due to precipitations or flooding events, which lead to a smoothing appearance to radar. The high temporal frequency of acquisition in Sentinel 1 (5–13 scenes/month) allowed the discrimination among climate and annual seasonality and episodic events in the C-band backscatter coefficient. On the other hand, ALOS-2/PALSAR-2 showed subsurface changes at L-band since the salinity of the brine in the soil reduces the penetration depth of backscattered power for shorter wavelengths. Results might be useful to monitor salars with geographic and weather conditions similar to Salar de Aguas Calientes Sur.

26 September 2020 in Preprints.org
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Preprint
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AJAlberto Jopia
Alberto Jopia
FZFrancisco Zambrano
Francisco Zambrano
WPWaldo Pérez-Martínez
Waldo Pérez-Martínez
PVPaulina Vidal-Páez
Paulina Vidal-Páez
JMJulio Molina
Julio Molina
FMFelipe De la Hoz Mardones
Felipe De la Hoz Mardones
For more than ten years, Central Chile faces drought conditions, which impact crop production and quality, increasing food security risk. Under this scenario, implementing management practices that allow increasing water use efficiency is urgent. The study was carried out in kiwifruit trees, located in the O’Higgins region, Chile; for season 2018-2019 and 2019-2020. We evaluate nine vegetation indices in the VNIR and SWIR regions derived from Sentinel-2 (A/B) satellites to know how much variability in the canopy water status could explain. Over the study's site were installed sensors that continuously measure the leaf's turgor pressure (Yara Water-Sensor). A strong correlation between turgor pressure and vegetation indices was obtained with the Spearman's rho coefficient ($\rho$). However, the NIR range's indices were influenced by the vegetative development of the crop rather than its water status. Red-edge showed better performance as the vegetative growth did not affect it. It is necessary to expand the study to consider higher variability in kiwifruit's water conditions and incorporate the sensitivity of different wavelengths.

12 July 2019 in Proceedings
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Conference Paper
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WPWaldo Pérez-Martínez
Waldo Pérez-Martínez
JPJosep E. Pardo-Pascual
Josep E. Pardo-Pascual
PVPaulina Vidal-Páez
Paulina Vidal-Páez
Josep E. Pardo-PascualJosep E. Pardo-Pascual
Josep E. Pardo-Pascual
The upper section of the Mapocho river basin is in constant danger of landslides. This study had the objective of zoning the upper Mapocho river basin for the susceptibility of landslides using hydrological, geological, and geomorphological data. Areas with a high degree of landslide susceptibility are located on the lower part of the main valleys as well as at the headwaters of the basins. Landslide events in the mountainous region of Central Chile are caused by two main factors: intense precipitation and seismic activity.

26 December 2018 in Revista de Teledetección
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Journal Article
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NMN. Medina
N. Medina
PVPaulina Vidal-Páez
Paulina Vidal-Páez
RCRenato Cifuentes
Renato Cifuentes
Jesus TorralbaJesus Torralba
Jesus Torralba
FKF. Keusch
F. Keusch
The Araucaria araucana is an endemic species from Chile and Argentina, which has a high biological, scientific and cultural value and since 2016 has shown a severe affection of leaf damage in some individuals, causing in some cases their death. The purpose of this research was to detect, from hyperspectral images, the individuals of the Araucaria species (Araucaria araucana (Molina and K. Koch)) and its degree of disease, by isolating its spectral signature and evaluating its physiological state through indices of vegetation and positioning techniques of the inflection point of the red edge, in a sector of the Ralco National Reserve, Biobío Region, Chile. Seven images were captured with the HYSPEX VNIR-1600 hyperspectral sensor, with 160 bands and a random sampling was carried out in the study area, where 90 samples of Araucarias were collected. In addition, from the remote sensing techniques applied, spatial data mining was used, in which Araucarias were classified without symptoms of disease and with symptoms of disease. A 55.11% overall accuracy was obtained in the classification of the image, 53.4% in the identification of healthy Araucaria and 55.96% in the identification of affected Araucaria. In relation to the evaluation of their sanitary status, the index with the best percentage of accuracy is the MSR (70.73%) and the one with the lowest value is the SAVI (35.47%). The positioning technique of the inflection point of the red edge delivered an accuracy percentage of 52.18% and an acceptable Kappa index.

22 August 2025 in Remote Sensing
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Journal Article
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PVPaulina Vidal-Páez
Paulina Vidal-Páez
JCJorge Clavero
Jorge Clavero
VRValentina Ramírez
Valentina Ramírez
AFAlfonso Fernández-Sarría
Alfonso Fernández-Sarría
Oliver Meseguer-RuizOliver Meseguer-Ruiz
Oliver Meseguer-Ruiz
FMFrancisco Mena
Francisco Mena
The upper Mapocho River basin, located in central Chile, has been affected by numerous landslides in the past, which may become more frequent due to a projected increase in intense precipitation events in the context of climate change. Against this background, this study aimed to analyze the ground deformation associated with an active landslide area in the Yerba Loca basin using the SBAS–DInSAR technique with PAZ and Sentinel-1 images acquired during two time periods, 2019–2021 and 2018–2022, respectively. Using PAZ imagery, the estimated vertical displacement velocity (subsidence) was as high as 9.6 mm/year between 2019 and 2021 in the area affected by the Yerba Loca multirotational slide in August 2018. Analysis of Sentinel-1 images indicated a vertical displacement velocity reaching −94 mm/year between 2018 and 2022 in the Yerba Loca landslide, suggesting continued activity in this area. It, therefore, may collapse again soon, affecting tourism services and the local ecosystem. By focusing on a mountainous region, this study demonstrates the usefulness of radar imagery for investigating landslides in remote or hard-to-reach areas, such as the mountain sector of central Chile.