In the last 10 years, the community of La Mesa de Macaracas (central Panama) has experienced cons... more In the last 10 years, the community of La Mesa de Macaracas (central Panama) has experienced considerable aftershocks due to earthquakes of magnitudes up to 5.7 Mw. Although most of the community consists of single-storey houses, the agricultural development in the region has led to multistorey building projects. To determine whether the characteristics of the soils could affect future construction in the study area, 16 stations were established to measure ambient vibrations and estimate the predominant frequencies and their corresponding H / V ratio peaks through the ambient noise H / V spectral ratio technique. According to the site class established by the Japan Road Association, the results revealed the existence of (a) soft soil with a range of predominant frequencies between 0.7 and 1.6 Hz, (b) medium soil with a range of predominant frequencies between 2.1 and 2.4 Hz, and (c) hard soil with a range of predominant frequencies between 2.6 and 2.9 Hz. In the first type (soft), t...
Congreso Nacional de Ciencia y Tecnología – APANAC, 2021
La ciénaga de las Macanas es el único humedal de agua dulce ubicado en las provincias centrales d... more La ciénaga de las Macanas es el único humedal de agua dulce ubicado en las provincias centrales de Panamá, con un área protegida de aproximada de 867 ha. Es categorizada un Área de Recursos Manejados por el Ministerio de Ambiente, donde se practica turismo, ecología, ganadería, agricultura y avistamiento de aves. La falta de estudios y datos actualizados del humedal, no han permitido evaluar su actividad hídrica en cuanto al desempeño del espejo de agua a través de los años. Es de especial atención, hacer un mayor monitoreo y análisis de la data de precipitación y de escorrentía, siendo estas unas de las principales entradas del cuerpo de agua. Este estudió emplea imágenes satelitales Landsat, descargadas del USGS Survey (https://earthexplorer.usgs.gov/). Los datos climatológicos fueron obtenidos de estaciones de ETESA y MIAMBIENTE. Se trabajará con la data recopilada en el lugar, para así promover la participación de actores claves interesados en un desarrollo sostenible de la zona...
2019 XLV Latin American Computing Conference (CLEI), 2019
In this article the development of a database of referenced spectral signatures from agricultural... more In this article the development of a database of referenced spectral signatures from agricultural land-cover for the Republic of Panama is presented. This database consists of reflectance spectra measured on crops and low vegetation, such as: rice, chili, onion, watermelon, maize and bare soil and of satellite images of their plots. Details of the integration process of the database and software developed for the manipulation of spectral signatures, are described. The Spectral Angle Mapping algorithm (SAM) is used for the supervised classification of the agricultural coverages in the database. On the one hand, results indicate the possibility of using this classification technique for the automatic determination of crops and even different phenological stages in a crop via a satellite image. On the other hand, results highlight the limitations of using this technique on recently planted crops and soil flooded by rain or with soil cultivated with a low agricultural cover crop. We foresee the use of this methodology and database for agricultural land surveys, crop management or used in the general organization of the territory.
Proceedings of the 16th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Innovation in Education and Inclusion”, 2018
The present investigation was focused on the variations in rainwater infiltration experienced by ... more The present investigation was focused on the variations in rainwater infiltration experienced by soils of Gamboa zone (Panama Canal Watershed) during various seasons of the year, employing a time-lapse analysis of electrical resistivity tomography (ERT). In 2009, a total of 3 geoelectrical tests were undertaken during the dry, transition and rainy seasons across a profile 47 m in length, strategically distributed on site. The results obtained in this study showed strong variations in calculated resistivity between these seasons, taking the dry season as a reference with decreases and increases of percent difference of resistivity between -20% and -100%, and between 50% and 100%, respectively. These decreases, when displayed through a sequence of time-lapse images, reveal a superficial extension of the water content variations along the entire profile, as well as strong inversion artifacts showing false increases of calculated electrical resistivity. Decreases are the product of the ...
Proceedings of the 16th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Innovation in Education and Inclusion”, 2018
This study focuses on the floristic diversity of the forest trees found at Cerro Pelado Tropical ... more This study focuses on the floristic diversity of the forest trees found at Cerro Pelado Tropical Hydrology Observatory in Gamboa, Colon, Panama. Field work for the quantitative inventory was carried out in November 2012. Data were collected by assessing the status of the forest in terms of tree species diversity and structure from one-hectare plot divided into twenty-five 20 m × 20 m quadrats. All tree species were identified, and their diameters at breast height (dbh) were measured. A total of 384 individuals with (dbh ≥ 10 cm) were counted, corresponding to 28 families, 41 genera, and 43 species of which Pera arborea, Oenocarpus mapora, Amaioua corymbosa, Vantanea depleta, and Matayba apetala were the species with the highest ecological weight, achieving 57.99% of the importance value index. Results were compared with plots from other forests of the Panama Canal watershed in terms of diversity and number of species per area and number of individuals. It was found that the habitat ...
Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XIII, 2007
Accurate estimation of sensible and latent heat fluxes as well as soil moisture from remotely sen... more Accurate estimation of sensible and latent heat fluxes as well as soil moisture from remotely sensed satellite images poses a great challenge. Yet, it is critical to face this challenge since the estimation of spatial and temporal distributions of these parameters over large areas is impossible using only ground measurements. A major difficulty for the calibration and validation of operational
In the last 10 years, the community of La Mesa de Macaracas (central Panama) has experienced cons... more In the last 10 years, the community of La Mesa de Macaracas (central Panama) has experienced considerable aftershocks due to earthquakes of magnitudes up to 5.7 Mw. Although most of the community consists of single-storey houses, the agricultural development in the region has led to multistorey building projects. To determine whether the characteristics of the soils could affect future construction in the study area, 16 stations were established to measure ambient vibrations and estimate the predominant frequencies and their corresponding H / V ratio peaks through the ambient noise H / V spectral ratio technique. According to the site class established by the Japan Road Association, the results revealed the existence of (a) soft soil with a range of predominant frequencies between 0.7 and 1.6 Hz, (b) medium soil with a range of predominant frequencies between 2.1 and 2.4 Hz, and (c) hard soil with a range of predominant frequencies between 2.6 and 2.9 Hz. In the first type (soft), t...
Congreso Nacional de Ciencia y Tecnología – APANAC, 2021
La ciénaga de las Macanas es el único humedal de agua dulce ubicado en las provincias centrales d... more La ciénaga de las Macanas es el único humedal de agua dulce ubicado en las provincias centrales de Panamá, con un área protegida de aproximada de 867 ha. Es categorizada un Área de Recursos Manejados por el Ministerio de Ambiente, donde se practica turismo, ecología, ganadería, agricultura y avistamiento de aves. La falta de estudios y datos actualizados del humedal, no han permitido evaluar su actividad hídrica en cuanto al desempeño del espejo de agua a través de los años. Es de especial atención, hacer un mayor monitoreo y análisis de la data de precipitación y de escorrentía, siendo estas unas de las principales entradas del cuerpo de agua. Este estudió emplea imágenes satelitales Landsat, descargadas del USGS Survey (https://earthexplorer.usgs.gov/). Los datos climatológicos fueron obtenidos de estaciones de ETESA y MIAMBIENTE. Se trabajará con la data recopilada en el lugar, para así promover la participación de actores claves interesados en un desarrollo sostenible de la zona...
2019 XLV Latin American Computing Conference (CLEI), 2019
In this article the development of a database of referenced spectral signatures from agricultural... more In this article the development of a database of referenced spectral signatures from agricultural land-cover for the Republic of Panama is presented. This database consists of reflectance spectra measured on crops and low vegetation, such as: rice, chili, onion, watermelon, maize and bare soil and of satellite images of their plots. Details of the integration process of the database and software developed for the manipulation of spectral signatures, are described. The Spectral Angle Mapping algorithm (SAM) is used for the supervised classification of the agricultural coverages in the database. On the one hand, results indicate the possibility of using this classification technique for the automatic determination of crops and even different phenological stages in a crop via a satellite image. On the other hand, results highlight the limitations of using this technique on recently planted crops and soil flooded by rain or with soil cultivated with a low agricultural cover crop. We foresee the use of this methodology and database for agricultural land surveys, crop management or used in the general organization of the territory.
Proceedings of the 16th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Innovation in Education and Inclusion”, 2018
The present investigation was focused on the variations in rainwater infiltration experienced by ... more The present investigation was focused on the variations in rainwater infiltration experienced by soils of Gamboa zone (Panama Canal Watershed) during various seasons of the year, employing a time-lapse analysis of electrical resistivity tomography (ERT). In 2009, a total of 3 geoelectrical tests were undertaken during the dry, transition and rainy seasons across a profile 47 m in length, strategically distributed on site. The results obtained in this study showed strong variations in calculated resistivity between these seasons, taking the dry season as a reference with decreases and increases of percent difference of resistivity between -20% and -100%, and between 50% and 100%, respectively. These decreases, when displayed through a sequence of time-lapse images, reveal a superficial extension of the water content variations along the entire profile, as well as strong inversion artifacts showing false increases of calculated electrical resistivity. Decreases are the product of the ...
Proceedings of the 16th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Innovation in Education and Inclusion”, 2018
This study focuses on the floristic diversity of the forest trees found at Cerro Pelado Tropical ... more This study focuses on the floristic diversity of the forest trees found at Cerro Pelado Tropical Hydrology Observatory in Gamboa, Colon, Panama. Field work for the quantitative inventory was carried out in November 2012. Data were collected by assessing the status of the forest in terms of tree species diversity and structure from one-hectare plot divided into twenty-five 20 m × 20 m quadrats. All tree species were identified, and their diameters at breast height (dbh) were measured. A total of 384 individuals with (dbh ≥ 10 cm) were counted, corresponding to 28 families, 41 genera, and 43 species of which Pera arborea, Oenocarpus mapora, Amaioua corymbosa, Vantanea depleta, and Matayba apetala were the species with the highest ecological weight, achieving 57.99% of the importance value index. Results were compared with plots from other forests of the Panama Canal watershed in terms of diversity and number of species per area and number of individuals. It was found that the habitat ...
Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XIII, 2007
Accurate estimation of sensible and latent heat fluxes as well as soil moisture from remotely sen... more Accurate estimation of sensible and latent heat fluxes as well as soil moisture from remotely sensed satellite images poses a great challenge. Yet, it is critical to face this challenge since the estimation of spatial and temporal distributions of these parameters over large areas is impossible using only ground measurements. A major difficulty for the calibration and validation of operational
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Papers by Jose Fabrega