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La caracterización geomorfológica es un elemento descriptivo del paisaje que permite la identificación de rasgos geofísicos resultantes y específicos en el tiempo a través de unidades. El presente trabajo es una propuesta alternativa para... more
La caracterización geomorfológica es un elemento descriptivo del paisaje que permite la identificación de rasgos geofísicos resultantes y específicos en el tiempo a través de unidades. El presente trabajo es una propuesta alternativa para la identificación de dichas unidades en el complejo paisajístico del archipiélago de San Andrés y Providencia, mediante el empleo de índices espectrales provenientes de imágenes satelitales WorldView 2 y 3, los cuales permiten mejorar la identificación y segmentación pictórica-morfológica de los elementos contenidos en las imágenes empleadas. Los resultados obtenidos, en contrastes con los publicados por autores; permiten identificar, detallar, estimar y evaluar un número mayor (más de diez) de unidades geomorfológicas a escala 1:2.000, la cuales fueron verificadas a través de validaciones estadísticas integradas con datos de campo. En el caso de resultados obtenidos mediante métodos tradicionales como ecosondeo multihaz y observaciones directas en...
Para llevar a cabo un monitoreo de inundaciones es importante identificar previamente las zonas más expuestas a estos desastres. A parte del uso de modelos climatológicos preparados en estaciones meteorológicas, es también altamente... more
Para llevar a cabo un monitoreo de inundaciones es importante identificar previamente las zonas más expuestas a estos desastres. A parte del uso de modelos climatológicos preparados en estaciones meteorológicas, es también altamente recomendable realizar estudios a través de técnicas de percepción remota mediante datos e imágenes satelitales. A continuación se expone un caso de monitoreo de inundaciones en las zonas de Colombia con mayor riesgo a sufrirlas.
The present work analyzes the existing relation between the different levels of severity in burns it, obtained from the CBI, and the structure of the landscape, measurement through the texture of satellite images. For it, the field data... more
The present work analyzes the existing relation between the different levels of severity in burns it, obtained from the CBI, and the structure of the landscape, measurement through the texture of satellite images. For it, the field data of a forest fire are used happened the 27 of June of 2003 to the southwest of the Community of Madrid, that was related to acquired images ALI and ASTER after the event. Measures of texture have calculated derived from the matrix of concurrences and the dimension fractal, relating them to the values of the index of severity (CBI) by means of statistical indices of correlation. Finally, the data of the correlation analysis are exposed, that shows a tendency the uniformity in the landscape as the severity level is increased on the vegetation. These increases vary based on the space and spectral resolution, being superior with greater space resolutions and the use of the SWIR that with the IRC. The results of this work show that indices of texture exist very related to the CBI, especially the homogeneity, with values of correlation of up to 0,71 in covers of pino piñonero (Pinus pinaster), and the average, with values that reach the-0,72 in oak covers.
Para la cartografía y monitoreo de los arrecifes de coral, un mapa batimétrico es útil como un mapa base. Diferentes métodos han sido desarrollados para cartografiar la batimetría usando sensores remotos. Dos grandes grupos se pueden... more
Para la cartografía y monitoreo de los arrecifes de coral, un mapa batimétrico es útil como un mapa base. Diferentes métodos han sido desarrollados para cartografiar la batimetría usando sensores remotos. Dos grandes grupos se pueden distinguir. El primero utiliza datos de teledetección de sensores activos y el segundo se basa en el empleo de sensores pasivos para generar información multiespectral. Este artículo se centra en el método de datos provenientes de sensores pasivos. Una modificación al método DOP “Profundidad de penetración” mediante espectrometría que se llevó a cabo en imágenes Landsat ETM+ sobre Archipiélago de San Andrés y Providen- cia (Colombia). Las mediciones de profundidad utilizadas en la validación del mo- delo fueron derivadas de lecturas de ecosonda en campo e interpolación de mapas batimétricos. La exactitud de la prueba reveló que el modelo batimétrico resultante es útil para el mapeo en zonas de arrecifes de coral del mar Caribe hasta 25m de profundidad a...
The increasing availability of EO data from the Copernicus program through its Sentinel satellites of the medium spatial and spectral resolution has generated new applications for risk management and disaster management. The recent growth... more
The increasing availability of EO data from the Copernicus program through its Sentinel satellites of the medium spatial and spectral resolution has generated new applications for risk management and disaster management. The recent growth in the intensity and number of hurricanes and earthquakes has demanded an increase in the monitoring of landslides. It is necessary to monitor large areas at a detailed level, which has previously been unsatisfactory due to its reliance on the interpretation of aerial photographs and the cost of high-resolution images. Using the differential Bare Soil Index for optical imagery interpretation in combination with cloud-computing in Google Earth Engine is a novel approach. Applying this method on a recent landslide event in Oaxaca in Mexico around 62% of the landslides were detected automatically, however, there is a big potential for improvement. Including NDVI values and considering images with a higher spatial resolution could contribute to the enh...
El uso de imagenes de sensores remotos para la caracterizacion de los ecosistemas marinos costeros requiere de la eliminacion previa de los efectos atmosfericos contenidos en las imagenes, lo cual puede realizarse de forma... more
El uso de imagenes de sensores remotos para la caracterizacion de los ecosistemas marinos costeros requiere de la eliminacion previa de los efectos atmosfericos contenidos en las imagenes, lo cual puede realizarse de forma semiautomatizada, mediante la utilizacion de algoritmos basados en supuestos alternativos contenidos en las herramientas de procesamiento para diferentes softwares. El objetivo central de este estudio fue comparar estadisticamente el comportamiento espectral de las coberturas contenidas en una imagen de alta resolucion WorldView-2 corregida atmosfericamente en funcion de los modelos ATCOR y empirico lineal (ELM), mediante espectrorradiometria de campo realizada en las zonas insulares del archipielago de San Andres y Providencia. El modelo de correccion ATCOR se aplico a traves del software Geomatica PCI 2015; en cuanto al modelo ELM, se utilizo el software ENVI. 5.2. Para la comparacion espectral se seleccionaron cuatro (4) tipos de coberturas (vegetacion, formaci...
Until now, most severity products are generated from a reclassification of dNBR index ranges. In this study, we focused on an automated global burn severity mapping approach. Using the catalogue of satellite imagery and the... more
Until now, most severity products are generated from a reclassification of dNBR index ranges. In this study, we focused on an automated global burn severity mapping approach. Using the catalogue of satellite imagery and the high-performance computing power of GoogleEarthEngine we propose an automated pipeline to generate severity maps of burned areas at a medium scale of 30 and 10m from the time series of Landsat and Sentinel2 images. Landsat-8 images available during 2020 and the dNBR spectral index were used to calculate the severity level of each pixel using a calibration model and linear regression adjustments, which were taken in the field from the CBI index in an app developed for field capture. A calibration approach was carried out to give the severity level of the final burned areas after several carefully designed logic filters on the normalized burn rate (NBR). This script focuses on the fires that occurred in Honduras in 2020. The regression model found a similar spatial...
This research: "The literary tale as a pedagogical mediation for the formation of a culture of peace and reconciliation in the fourth grade of the Liceo Hermano Miguel La Salle", in the context of the Masters in Teaching of the... more
This research: "The literary tale as a pedagogical mediation for the formation of a culture of peace and reconciliation in the fourth grade of the Liceo Hermano Miguel La Salle", in the context of the Masters in Teaching of the University of La Salle, within the macroproject : "Pedagogies for peace and reconciliation in postconflict" belonging to the research line: "Culture, Faith and Training in Values." Those who, in continuous accompaniment of the tutor Olga Lucía Bejarano Bejarano, embark on this odyssey to propose the Literary Story as a pedagogical mediation in the school context and, from this scenario, contribute to the reflection and the gradual transformation of the educational actors towards the Building a culture of peace. During the development of this research we focus on the question "What is the contribution of the literary tale as a pedagogical mediation for the formation of a culture of peace ?, in order to answer it, we are based...
A study was done to explore the suitability of intersection and arterial collision prediction models based on traffic conflicts, generated using the Paramics microsimulation suite and the Surrogate Safety Assessment Model (SSAM). A linear... more
A study was done to explore the suitability of intersection and arterial collision prediction models based on traffic conflicts, generated using the Paramics microsimulation suite and the Surrogate Safety Assessment Model (SSAM). A linear regression model and a generalized linear model with a negative binomial error structure were explored to correlate conflicts to crash rates, as well as the conflict-based models suggested by SSAM. The model predictions were compared to volume-based predictions and historical data from Toronto, Ontario, Canada. The volumebased predictions were calculated using a negative binomial generalized linear model, fitted to the same arterial and intersection sets used to fit the conflict-based models. The results show the predictions generated by a conflict-based model were comparable for intersections, but poor for
Antecedentes: La interfaz remota de las Aeronaves remotamente tripuladas (ART) reduce la percepción directa del entorno operacional propiciando el error humano en cerca del 35% de los eventos de seguridad reportados, por lo que el estudio... more
Antecedentes: La interfaz remota de las Aeronaves remotamente tripuladas (ART) reduce la percepción directa del entorno operacional propiciando el error humano en cerca del 35% de los eventos de seguridad reportados, por lo que el estudio de la toma de decisiones de sus operadores es necesario. Objetivo: Describir el funcionamiento neuropsicológico y las respuestas fisiológicas asociadas que participan en la toma de decisiones en los operadores de ART para establecer las diferencias entre los operadores según su experiencia en la operación del equipo. Método: Estudio no experimental, de corte transversal correlacional-causal. Se realizó monitoreo fisiológico (EDA y HRV), y electroencefalográfico (EEG) en misiones del simulador de Scan–Eagle, y se administró la batería BANFE-2 e IGTv2. Resultados: 17 operadores masculinos de 28±2.7 años fueron evaluados. Los operadores con < 500 horas de vuelo presentan una actividad cerebral frontal de predominio dorsolateral con pensamiento refl...
Los eventos de seguridad no deseados en las Aeronaves Remotamente Tripuladas (art) tipo Scan Eagle se han atribuido a los errores humanos, en particular, en latoma de decisiones y los errores durante la operación, los cuales pueden ser... more
Los eventos de seguridad no deseados en las Aeronaves Remotamente Tripuladas (art) tipo Scan Eagle se han atribuido a los errores humanos, en particular, en latoma de decisiones y los errores durante la operación, los cuales pueden ser susceptibles a mejorar con entrenamiento específico como medida para mitigar el riesgo de accidentes. Este artículo propone una herramienta de entrenamiento basada en el funcionamiento neuropsicológico para los operadores de art en la Fuerza Aérea Colombiana, para el mejoramiento de habilidades y gestión del riesgo, basada en el funcionamiento neuropsicológico y las áreas cerebrales. Se empleó un método de estudio no experimental de corte transversal analítico, realizando monitoreo de la actividad eléctrica cerebral mediante electroencefalografía (EEG) con el equipo B-alert x10, durante misiones reproducidas en simulador de Scan Eagle para identificar las áreas de actividad cerebral en frecuencia beta, y se aplicó  la batería banfe-2 para evaluar func...
Durante la última década, ha habido un número creciente de trabajos publicados sobre la gravedad de los incendios forestales utilizando datos de teledetección para fines de gestión de recursos naturales y de investigación. Muchos de estos... more
Durante la última década, ha habido un número creciente de trabajos publicados sobre la gravedad de los incendios forestales utilizando datos de teledetección para fines de gestión de recursos naturales y de investigación. Muchos de estos estudios cuantifican los cambios entre las condiciones de vegetación antes y después del incendio a partir de imágenes satelitales utilizando índices espectrales; sin embargo, hay una discusión activa sobre cuál de los índices más comúnmente usados es más adecuado para estimar la severidad de la quemadura, y qué metodología es la mejor para la estimación de los niveles de severidad. Este estudio propone y evalúa un algoritmo de aprendizaje automático de Estimación de Máxima Verosimilitud (EMV) para mapear la severidad de las quemaduras como una alternativa a los modelos de regresión.Desarrollamos ambos métodos usando datos de campo de GeoCBI (Índice Compuesto de Quema Geométricamente Estructurado, siglas en inglés) y seis índices espectrales difere...
The severity of forest fires derived from remote sensing data for research and management has become increasingly widespread in the last decade, where these data typically quantify the pre- and post-fire spectral change between satellite... more
The severity of forest fires derived from remote sensing data for research and management has become increasingly widespread in the last decade, where these data typically quantify the pre- and post-fire spectral change between satellite images on multi-spectral sensors. However, there is an active discussion about which of the main indices (dNBR, RdNBR or RBR) is the most adequate to estimate the severity of the fire, as well about the adjustment model used in the classification of severity levels. This study proposes and evaluates a new technique for mapping severity as an alternative to regression models, based on the use of the maximum likelihood estimation (MLE) automatic learning algorithm, from GeoCBI field data and spectral indices dNBR, RdNBR and RBR applied to Landsat TM, ETM+ Images, for two fires in central Spain. We compare the severity discrimination capability on dNBR, RdNBR and RBR, through a spectral separability index (M) and then evaluated the concordance of these...
Although macro-scale synthetic jets are well studied, our knowledge of the behaviour of micro-scale synthetic jets is still extremely limited due to the difficulty in performing detailed measurements with a desirable spatial solution. In... more
Although macro-scale synthetic jets are well studied, our knowledge of the behaviour of micro-scale synthetic jets is still extremely limited due to the difficulty in performing detailed measurements with a desirable spatial solution. In the work presented in this paper, a PIV study of the characteristics of synthetic jets issued into quiescent air from orifices of 5mm and 0·5mm diameter respectively is undertaken. It is found that the vortex rollup is much weaker for the 0·5mm jets due to their low Stokes number which results in a near parabolic exit velocity profile. To ensure an appreciable vortex rollup that is desirable for effective flow control, the actuator has to be operated at much higher frequencies to ensure that the Stokes number is greater than a certain threshold value. Furthermore the study shows that the characteristics of synthetic jets of different scales are identical when the dimensionless stroke length (L), Stokes number (S) and Reynolds number (Re L ) are the ...
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Safety prediction models are designed to estimate the safety of a road entity and, in most cases, they link traffic volumes to crashes. A major problem with such models is that, because crashes are rare events, crash statistics cannot... more
Safety prediction models are designed to estimate the safety of a road entity and, in most cases, they link traffic volumes to crashes. A major problem with such models is that, because crashes are rare events, crash statistics cannot account for many of the possible contributing factors. Using traffic conflicts to measure safety can overcome this problem because conflicts occur more frequently than crashes do and can be either measured in the field or estimated with microsimulation models. This study developed crash prediction models from simulated peak hour conflicts for a group of urban four-legged signalized intersections in Toronto, Ontario, Canada, and evaluated their predictive capabilities. Case studies with two microsimulation packages, VISSIM and Paramics, demonstrated the use of microsimulation for estimating safety performance. For a further demonstration of the approach's versatility, VISSIM was used with precalibrated parameter values, while substantial effort was ...
Undoubtedly the importance of acquiring Earth Observation satellite information for a country is a priority since these images can have different uses such as cartography, disaster, climate change impact, border control, or in general to... more
Undoubtedly the importance of acquiring Earth Observation satellite information for a country is a priority since these images can have different uses such as cartography, disaster, climate change impact, border control, or in general to sustainable development, even more for developing countries. Continually, a large volume of global coverage satellite data is collected and supplied. However, availability of open-source data remains under-leveraged. For this reason, this research is focused on the study of the radar satellite images that are useful for monitoring and drug trafficking control support, through the detection of vessels used by organized crime that do not have tracking systems on board, for example, small fishing boats or those dedicated to trafficking illicit substances. Synthetic Aperture Radar (SAR) data can currently be processed from full catalogs on cloud servers (as Google Earth Engine) available to researchers who process vessel detection algorithms with optical or radar images. Today’s satellite SARs data that can be used for maritime surveillance include TerraSAR-X (Germany), Cosmo-SkyMed (Italy), Radarsat-2 (Canada), Alos-Palsar-2 (Japan), Kompsat-5 (Korea), Risat (India) and Sentinel-1 of European Space Agency (ESA, Europe). What sets Sentinel-1 apart from all these other systems is that it is routinely collecting images which are available for free due to the open data policy of the European Union (EU) Copernicus Program. This research seeks to develop a methodology that supports the detection of illegal marine vessels, such as small fishing boats or those dedicated to trafficking illicit drug substances, by using Sentinel-1 available SAR data, applied in a pilot area over the coastal regions of Pacific Colombian. By utilization of the Constant False Alarm Rate (CFAR) algorithm provided by Sentinel Application Platform (SNAP) software from ESA, the rapid detection of ships is proven and thus provides sufficient results for a future implementation to support the combat of organized crime.
El fuego es uno de los factores ambientales de mayor influencia en la definicion y desarrollo de los ecosistemas forestales, afectando su densidad, composicion y estructura espacial del paisaje. El conocimiento del comportamiento de los... more
El fuego es uno de los factores ambientales de mayor influencia en la definicion y desarrollo de los ecosistemas forestales, afectando su densidad, composicion y estructura espacial del paisaje. El conocimiento del comportamiento de los incendios forestales es de vital importancia en la gestion forestal. La comprension de factores como la severidad, intensidad o frecuencia podrian conducir a esfuerzos de supresion mas eficaces en la gestion de incendios. Por esta razon, este trabajo analiza los cambios en la estructura y configuracion del paisaje producidos a consecuencia de incendios forestales, basandose para ello en metricas de paisaje y tecnicas de teledeteccion, mediante el uso de indices espectrales derivados de imagenes Landsat TM, ETM+ y OLI, con el fin de analizar los patrones espacio-temporales producidos por el fuego y mas especificamente por la severidad del incendio. Para ello, se evaluan diferentes tecnicas de cartografia de severidad del incendio, la caracterizacion d...
Las tecnologías geoespaciales evolucionan exponencialmente, ejemplo, la percepción remota, que ofrece posibilidades de identificación y medición a partir de la radiación captada por sensores registrando patrones únicos reflejados por la... more
Las tecnologías geoespaciales evolucionan exponencialmente, ejemplo, la percepción remota, que ofrece posibilidades de
identificación y medición a partir de la radiación captada por sensores registrando patrones únicos reflejados por la superficie de
los cuerpos, denominados firmas espectrales, que constituyen información valiosa para múltiples aplicaciones temáticas. Colombia,
aunque presenta desarrollos en materia de teledetección, no cuenta con un sistema que permita acopiar y usar información espectral
de manera estandarizada y confiable. Este trabajo describe conceptualmente una propuesta para diseñar, desarrollar e implementar
un Sistema de Información Espectral para Colombia (SIEC), a partir del desarrollo de tres componentes: la gestión de la información,
la gestión del conocimiento y la plataforma tecnológica. Se describe un desarrollo metodológico para construir una plataforma
tecnológica (aplicación web) así como el diseño de un estándar para el registro de datos de las firmas espectrales (sensor, iluminación,
geometría). El SIEC se presenta como una herramienta enmarcada en un ambiente colaborativo articulado a la Infraestructura
Colombiana de Datos Espaciales (ICDE), orientada a potenciar el uso de firmas y bibliotecas espectrales a partir de un metadato
estructurado en tres grupos de información con aproximadamente 127 atributos, dispuestos sobre una plataforma tecnológica que
brinda inicialmente bajo una vista lógica siete funcionalidades esenciales de servicio. Finalmente, se establecen retos futuros, en
especial acuerdos interinstitucionales para consolidar y aprovechar la información espectral.
El Santuario de Flora y Fauna Ciénaga Grande de Santa Marta (SSF-CGSM) es uno de los ecosistemas costeros de mayor extensión e importancia en Colombia, siendo el bosque de manglar la cobertura que predomina en este lugar. Desde el año... more
El Santuario de Flora y Fauna Ciénaga Grande de Santa Marta (SSF-CGSM) es uno de los ecosistemas costeros de mayor
extensión e importancia en Colombia, siendo el bosque de manglar la cobertura que predomina en este lugar. Desde el año 1956,
se han dado extensos problemas de mortalidad del manglar por la hipersalinización de los suelos, ocasionando una alteración en
la conectividad hidrológica y biológica. Por lo anterior, se requiere contar con una cartografía dinámica y precisa de dichos bosques
inundables, la cual sea realizada con metodologías replicables que permitan evaluar la extensión real de cambios periódicos. En esta
investigación, se evaluó la dinámica del manglar y otras coberturas asociadas en el SSF-CGSM mediante técnicas Cloud Computing,
a través de imágenes de satélite Landsat 5 TM, 7 ETM+ y 8 OLI-LDCM en los últimos 22 años. Se emplearon técnicas de procesamiento
digital para la remoción de nubes, apilado denso, clasificación Randon Forest y detección de cambios desde la aplicación de Google
Earth Engine (GEE). Se encontraron cambios importantes con pérdida de manglar hasta el año 2005 (1097 ha), y un proceso de
recuperación que continúa en el 2017 a una tasa 160 ha/año. La validación de la técnica mostró una precisión total entre 85.14 % y
98.5 % y un Kappa estadístico entre 0.76 y 0.86. Este estudio ha demostrado el potencial de usar la plataforma GEE para identificar
cambios y cartografiar los bosques de manglares como los analizados en la CGSM. Las técnicas novedosas de procesamiento Cloud
con GEE representan una alternativa de procesamiento computacional rápida sobre extensos catálogos de imágenes de escala global
y uso gratuito, con ventajas comparativas frente a otras metodologías tradicionales empleadas para la cartografía de coberturas de
manglar en el país.
Resumen: Los incendios forestales causan la destrucción de la cubierta vegetal, alterando la estructura del paisaje en un grado que suele estar correlacionado con la severidad del incendio. La teledetección puede jugar un papel... more
Resumen: Los incendios forestales causan la destrucción de la cubierta vegetal, alterando la estructura del paisaje en un grado que suele estar correlacionado con la severidad del incendio. La teledetección puede jugar un papel preponderante en el estudio de estas alteraciones, en el corto, medio y largo plazo. Este trabajo analiza los cambios espacio-temporales RFXUULGRVVHQQODDHVWUXFWXUDDGHOOSDLVDMHHUHODFLRQDGRVVFRQQHOOQLYHOOGHHVHYHULGDGGGHOOLQFHQGLRRIRUHVWDOOGHH3DQWDQRRGHH6DQQ-XDQQ 0DGULGGHHMXQLRRGHHKDPHGLDQWHHLPiJHQHVV/DQGVDW70(70\\2/,GXUDQWHHHOOSHULRGRRDD La metodología ha consistido en el cálculo del índice de campo GeoCBI y del índice espectral RBR (Relativized Burn Ratio) para la estimación de la severidad, así como del índice NBR (Normalized Burned Ratio) para el cálculo de métricas de textura extraídas de la matriz de co-ocurrencia (GLCM) y de la dimensión fractal (DF). Los resultados permiten cuantificar el efecto espacio-temporal del incendio sobre la estructura del paisaje, evidenciando la relación directa entre el nivel de severidad y el grado de homogeneidad, así como el escaso efecto que las repoblaciones forestales han tenido en la estructura del paisaje casi 10 años después. Palabras clave: Severidad, GeoCBI, NBR, RBR, estructura del paisaje, dimensión fractal. Abstract: Forest fires cause the destruction of the vegetation cover, altering the structure of the landscape to a degree that is often correlated with the severity of the fire. Therefore, remote sensing plays a preponderant role in the study of these alterations, in the short, medium and long term. This work analyzes the spatial and temporal changes that occurred in the landscape structure related to the severity of the forest fire in the San Juan marsh (Madrid) in June 2003, with an affected area of 857 ha, using Landsat-TM images, ETM + and OLI, during the period from 2002 to 2016. The methodology consisted in the calculation of the GeoCBI field index and the Relative Burn Ratio (RBR) for severity estimation, as well as the Normalized Burned Ratio (NBR), for the calculation of texture metrics extracted from the co-occurrence matrix (GLCM) and the fractal dimension (DF). The results allow quantification of the spatial-temporal effect of the fire on the structure of the landscape, evidencing the direct relationship between the level of severity and the degree of homogeneity, as well as the scarce effect that management has had on the structure of the landscape almost 10 years later.
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ABSTRACT We describe twelve previously undocumented Pigerodendron uviferum D.Don (Florin) populations outside of protected areas at the northern limit of the Chilean Coast Range (from 39º43'-40º S), extending their northern... more
ABSTRACT We describe twelve previously undocumented Pigerodendron uviferum D.Don (Florin) populations outside of protected areas at the northern limit of the Chilean Coast Range (from 39º43'-40º S), extending their northern limits. These small swamp-populations are isolated within a matrix of pastures and exotic forest plantations, and are subject to “chronic” anthropogenic disturbances.
... 134 p. [ Links ]. Lara A, C Donoso, B Escobar, A Rovere, A Premoli, DP Soto, J Bannister. 2006. Pilgerodendron uviferum (D. Don) Florin. ... [ Links ]. Soto DR 2004. Estado de conservación de Pilgerodendron uviferum (D. Don) Florin,... more
... 134 p. [ Links ]. Lara A, C Donoso, B Escobar, A Rovere, A Premoli, DP Soto, J Bannister. 2006. Pilgerodendron uviferum (D. Don) Florin. ... [ Links ]. Soto DR 2004. Estado de conservación de Pilgerodendron uviferum (D. Don) Florin, en la Cordillera de la Costa, Valdivia. ...
Resumen  Dos especies nuevas de Borreria son descritas: la primera, Borreria johnwoodii del cerrado del Parque Nacional Noel Kempff Mercado; la segunda, Borreria siberiana del Bosque Nublado Yungueño entre 2600 y 3100 m sobre el nivel del... more
Resumen  Dos especies nuevas de Borreria son descritas: la primera, Borreria johnwoodii del cerrado del Parque Nacional Noel Kempff Mercado; la segunda, Borreria siberiana del Bosque Nublado Yungueño entre 2600 y 3100 m sobre el nivel del mar. Declieuxia cordigera es registrado por primera vez para Bolivia. Borreria nectarifera es tratado como sinónimo de B. eryngioides var. affinis.
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The use of remote sensing images for the characterization of the coastal marine ecosystems requires the prior removal of the atmospheric effects, which can be done in a semi-automated manner, by the use of algorithms based on alternative... more
The use of remote sensing images for the characterization of the coastal marine ecosystems requires the prior removal of the atmospheric effects, which can be done in a semi-automated manner, by the use of algorithms based on alternative assumptions contained in the processing tools for different software packages. The main objective of this study was to statistically compare the spectral behavior of the coverages contained in a high-resolution WorldView-2 image atmospherically corrected according to the ATCOR and empirical linear models (ELM), using field spectroradiometry conducted in the insular areas of the archipelago of San Andres and Providence. The ATCOR correction model was applied through the PCI 2015 Geomatics software; regarding the ELM model, the ENVI 5.2 software was used. For the spectral comparison four (4) types of coverage were selected (vegetation, reef formations, beach sand and submerged sandbank), with twenty (20) replicas each, for a total of eighty (80) sampling points distributed in a stratified way in the image. The statistical results showed a linear correlation greater than 0.9 between the reflectance values for each of the bands (Blue, Green, Red and NIR-1) and indicate that both models of the atmospheric correction have a high capacity to eliminate the atmospheric effects present in this type of images. However, there are minor significant differences between the middle quadratic errors in the reflectance values for each band of the corrected images.
For mapping and monitoring coral reefs, a bathymetric map is useful as a base map. Different methods have already been developed to map bathymetry using remote sensing. Two main groups can be distinguished. One group is using active... more
For mapping and monitoring coral reefs, a bathymetric map is useful as a base map. Different methods have already been developed to map bathymetry using remote sensing. Two main groups can be distinguished. One group is using active remote sensing data; the other is based on passive sensor generated multi-spectral information. In this article, the focus is on the passive data method. A modified DOP «depth of penetration» mapping method was implemented on a Landsat ETM+ image over Archipelago San Andres (Colombia). Depth measurements used in the validation of the model were derived from the interpolation of bathymetric maps. The accuracy test revealed that the resulting bathymetric map is useful for coral reef mapping, but care should be taken when using it. Deviations from reality were caused by assumptions inherent to the theory used, data interpolation, satellite image characteristics and errors during implementation of the method.
Research Interests:
The tropical glaciers exhibit significant changes in answer to the variations of the climatic conditions, being observed a constant and progressive loss in the last 100 years. The estimation of the surface glacier from Landsat images... more
The tropical glaciers exhibit significant changes in answer to the variations of the climatic conditions, being observed a constant and progressive loss in the last 100 years. The estimation of the surface glacier from Landsat images constitutes an optimal tool in the determination of the backward movement state glacier. Most of the studies until now published is based on the aerial photo interpretation. The main objective of the present work was to evaluate the potential change of the fluctuations in the line of snow of the Nevado del Huila volcano locate at Central Mountain Chain of Colombia, during an interval of 25 years, by means of the use of NDSI (Normalized Difference Snow Index) like method for the automatic extraction , applied to images of satellite TM and ETM+. The results, for 1976-2001 period show a continuous and constant backward movement of glacial surface, with a lost of 5,33 Km 2. It constitutes a reduction of 27% of its area in 25 years. Resumen Los glaciares tropicales exhiben cambios significativos en respuesta a las variacio-nes de las condiciones climáticas, observándose una pérdida constante y progresiva en los últimos 100 años. La estimación de la superficie glaciar a partir de imágenes Landsat constituye una herramienta óptima en la determinación del estado de retro-ceso glaciar. La mayor parte de los estudios hasta ahora publicados se basan en la interpretación de fotografías aéreas. El propósito principal del presente trabajo fue evaluar el cambio potencial de las fluctuaciones en la línea de nieve del volcán Nevado del Huila en los Andes centrales de Colombia, durante un intervalo de 25
Antes de 1972, la idea de utilizar datos de satélite para la vigilancia terrestre, la cartografía o la exploración era un concepto visionario. Hecho que da origen al Programa Landsat, el cual se constituye en una serie de misiones de... more
Antes de 1972, la idea de utilizar datos de satélite para la vigilancia terrestre, la cartografía o la
exploración era un concepto visionario. Hecho que da origen al Programa Landsat, el cual se
constituye en una serie de misiones de observación de la tierra por satélite gestionadas
conjuntamente por la NASA y el Servicio Geológico de Estados Unidos (USGS). El programa Landsat
ha revolucionado la forma de ver y estudiar nuestro planeta. Esta serie de datos, que se inició en
1972, es la más larga de la historia y continua registrando los cambios en la superficie terrestre
desde el espacio. Landsat ha sido el único sistema de satélite diseñado y operado para observar
repetidas veces la cubierta de la tierra con una resolución moderada; de manera general cada pixel
en su imagen tiene un tamaño con el que se podría cubrir un campo de béisbol.
En la actualidad el programa se encuentra en su octava versión denominada: “Landsat Data
Continuity Mission” (LDCM) es el octavo satélite de observación de la serie Landsat y continuará el
legado de archivo de los anteriores satélites, convirtiéndose de esta manera en el futuro de los
satélites de observación de la tierra de mediana resolución con más historia. Este programa amplía,
mejora y avanza en el registro de imágenes mutiespectrales, mantenimiento la misma calidad de
sus siete predecesores.
Research Interests:
Undoubtedly the importance of acquiring Earth Observation satellite information for a country is a priority since these images can have different uses such as cartography, disaster, climate change impact, border control, or in general to... more
Undoubtedly the importance of acquiring Earth Observation satellite information for a country is a priority since these images can have different uses such as cartography, disaster, climate change impact, border control, or in general to sustainable development, even more for developing countries. Continually, a large volume of global coverage satellite data is collected and supplied. However, availability of open-source data remains under-leveraged. For this reason, this research is focused on the study of the radar satellite images that are useful for monitoring and drug trafficking control support, through the detection of vessels used by organized crime that do not have tracking systems on board, for example, small fishing boats or those dedicated to trafficking illicit substances. Synthetic Aperture Radar (SAR) data can currently be processed from full catalogs on cloud servers (as Google Earth Engine) available to researchers who process vessel detection algorithms with optical or radar images. Today’s satellite SARs data that can be used for maritime surveillance include TerraSAR-X (Germany), Cosmo-SkyMed (Italy), Radarsat-2 (Canada), Alos-Palsar-2 (Japan), Kompsat-5 (Korea), Risat (India) and Sentinel-1 of European Space Agency (ESA, Europe). What sets Sentinel-1 apart from all these other systems is that it is routinely collecting images which are available for free due to the open data policy of the European Union (EU) Copernicus Program. This research seeks to develop a methodology that supports the detection of illegal marine vessels, such as small fishing boats or those dedicated to trafficking illicit drug substances, by using Sentinel-1 available SAR data, applied in a pilot area over the coastal regions of Pacific Colombian. By utilization of the Constant False Alarm Rate (CFAR) algorithm provided by Sentinel Application Platform (SNAP) software from ESA, the rapid detection of ships is proven and thus provides sufficient results for a future implementation to support the combat of organized crime.
En nuestro país se habla de forma recurrente de la necesidad de conservar la naturaleza. Tradicionalmente la conservación es interpretada como la preservación a ultranza de ciertos territorios pero actualmente se consideran otros... more
En nuestro país se habla de forma recurrente de la necesidad de conservar la
naturaleza. Tradicionalmente la conservación es interpretada como la preservación a
ultranza de ciertos territorios pero actualmente se consideran otros escenarios alternos
además de la preservación estricta de nuestro patrimonio natural, dentro de dichos
escenarios está el uso sostenible de nuestros recursos y por supuesto la restauración
de nuestras áreas degradadas, esta última alternativa destaca en un país en el que
al menos el 40 % de su territorio continental ha sido degradado, pero no somos los
únicos con éste problema y la preocupación frente a la degradación ecosistémica ha
llegado más allá del ámbito ambiental y ya alcanza la toma de decisiones políticas
nacionales e internacionales, precisamente porque afecta no solo la biodiversidad
sino la oferta y la calidad de los servicios ecológicos que nuestro patrimonio natural
presta, afectando a las comunidades locales y su relación con la naturaleza.
Research Interests:
This paper describes the prototype of an automatic correction model of satellite images for automatic extraction of water areas, referred to as: "CAIN" (Atmospheric Correction and Indexes flood) processing platform developed under the PCI... more
This paper describes the prototype of an automatic
correction model of satellite images for automatic
extraction of water areas, referred to as: "CAIN"
(Atmospheric Correction and Indexes flood) processing
platform developed under the PCI Geomatica Software
2013 the framework of the technical assistance to the
Colombian Corporation of Agricultural Research
(CORPOICA) which in turn is part of the initiative of
the UN- SPIDER network for the management of spatial
information management and responses to disasters and
emergencies. The CAIN model to automate processes
such as the conversion of digital numbers (DNs) to
absolute units of spectral radiance (Lsat) and actual
surface reflectance (REF). Providing a basis for
comparison of standardized data in a scene both as
images acquired from different dates and sensors in
order to determine using remote sensing technology
levels and flooded areas analyzed by radiometric indices
of vegetation and water.
This work is confirmed as a great tool in the analysis
and comparison of water bodies, while allowing
mapping change to determine the areas affected by
floods, thus providing valuable information for
managers to characterize and current state of knowledge
of the effects of climate change.
Workshop report The workshop was held at the National Commission for Knowledge and Use of Biodiversity (CONABIO) in Mexico City during the first week of August. Participants were located at a nearby Radisson hotel. We had 15 speakers and... more
Workshop report The workshop was held at the National Commission for Knowledge and Use of Biodiversity (CONABIO) in Mexico City during the first week of August. Participants were located at a nearby Radisson hotel. We had 15 speakers and several invited participants. One participant, Carlos Souza, from Brazil was invited via " web meeting " to present his experience in the project http://mapbiomas.org/ in the context of the Google Earth Engine (EE) collaborative environment.
Research Interests:
Para llevar a cabo un monitoreo de inundaciones es importante identificar previamente las zonas más expuestas a estos desastres. A parte del uso de modelos climatológicos preparados en estaciones meteorológicas, es también altamente... more
Para llevar a cabo un monitoreo de inundaciones es importante identificar previamente las zonas más expuestas a estos desastres. A parte del uso de modelos climatológicos preparados en estaciones meteorológicas, es también altamente recomendable realizar estudios a través de técnicas de percepción remota mediante datos e imágenes satelitales. A continuación se expone un caso de monitoreo de inundaciones en las zonas de Colombia con mayor riesgo a sufrirlas.
Research Interests:
El presente documento corresponde al informe final del Convenio Interadministrativo No. 1017 de 2013 suscrito entre CORANTIOQUIA y el Instituto Alexander von Humboldt – IAvH -, con el objeto de “Aunar esfuerzos técnicos, administrativos,... more
El presente documento corresponde al informe final del Convenio Interadministrativo No.
1017 de 2013 suscrito entre CORANTIOQUIA y el Instituto Alexander von Humboldt – IAvH
-, con el objeto de “Aunar esfuerzos técnicos, administrativos, económicos y financieros
para fortalecer el conocimiento, la conservación y el uso sostenible de la biodiversidad y los
servicios ecosistémicos del bosque seco tropical en la jurisdicción de CORANTIOQUIA, en
el marco del convenio No. 949 suscrito entre el IAvH y CORANTIOQUIA”. En este se
presenta en cumplimiento de la cláusula cuarta, numeral (d), informe final que da cuenta de
la ejecución del 100% del objeto. Con este informe, se hace explícito el cumplimiento a cada
uno de los compromisos, relacionados a continuación y con sus respectivas actividades
The existing gaps in the geospatial field amongst countries make it difficult to manage information and monitor compliance with sustainable development goals (SDG). These gaps are the result of the lack of a space policy in most... more
The existing gaps in the geospatial field amongst countries make it difficult to manage information and monitor compliance with sustainable development goals (SDG). These gaps are the result of the lack of a space policy in most developing countries, plus numerous deficiencies in Science, Technology and Innovation. Understanding the importance of geospatial technologies to promote sustainable development, Colombia has developed its space policies in two major areas: Geographic Information-Spatial Data Infrastructure (2009) and Earth Observation (2010), which have allowed the partial articulation between the State, academia and the private sector through the formation of the Colombian Space Commission (CCE) and the Colombian Spatial Data Infrastructure (ICDE). Implementing these policies has also required the generation of guidelines in the field of information and communication technologies (ICT), an example is the National Data Harvesting Policy (Big Data) of 2018, which addresses the paradigm of dealing with large amounts of data of heterogeneous characteristics and in real time. It is essential to improve the functioning of the public sector on a global scale, and, to monitor compliance with the SDGs. Global trends show that only 10% of developing countries have carried out at least one project to measure ODS indicators regarding Big Data, (DNP, 2018). Colombia has challenges to achieve the measurement of 46% of the global indicators of ODS (Idem), currently the country is working to make the application of Big Data technologies facilitate the measurement of these indicators. Entities such as DANE have already developed projects with Big Data technologies, which have made it possible to measure indicators related to the occupation of urban land and access to passable roads by rural populations. Despite results and advances, Colombia still has not met the geospatial informational needs for aiding in its sustainable development. There is, however, an opportunity to use science, technology and geospatial innovation in Colombia's compliance with the SDGs, based on the understanding and development of a space policy according to the needs of the country.
MATERIALES Retos y aplicaciones de los inventarios forestales INIA (Madrid) 11 de junio de 2019 Los incendios forestales causan la destrucción de la cubierta vegetal, alterando su estructura y funcionalidad en un grado que suele estar... more
MATERIALES Retos y aplicaciones de los inventarios forestales INIA (Madrid) 11 de junio de 2019 Los incendios forestales causan la destrucción de la cubierta vegetal, alterando su estructura y funcionalidad en un grado que suele estar correlacionado con la severidad y el tipo de incendio. El seguimiento de la regeneración de las cubiertas vegetales permite estimar el grado de recuperación de la cubierta y su composición, explorar la influencia de factores externos (meteorología, repoblaciones), o analizar la respuesta de la vegetación en relación a la severidad causada por el fuego. El presente trabajo se centra en el seguimiento de las cubiertas vegetales tras el incendio forestal ocurrido en las proximidades del pantano de San Juan (Madrid) en junio de 2003, con una superficie afectada de 840ha. El objetivo es estimar el grado de recuperación de la cubierta así como su composición en relación al estado pre-fuego, a escala de detalle. Para ello se han utilizado datos de campo, orto-fotografías aéreas (vuelo Oleícola, PNOA), datos LiDAR (PNOA, primera y segunda cobertura) y cartografía auxiliar (Mapa Forestal de España, otros mapas). A partir de estos datos se han obtenido datos sobre la estructura horizontal y vertical, y sobre la composición vegetal, que han permitido de manera conjunta y sinérgica cuantificar espacio-temporalmente la recuperación de la cubierta vegetal del área incendiada, así como el escaso efecto de las repoblaciones forestales planificadas y ejecutadas entre 2005 y 2007.
This work addresses the construction of a specialized network to promote the development, use, and appropriation of modern technologies for the characterization of marine ecosystems in Colombia. The efforts have been leaded by the... more
This work addresses the construction of a specialized network to promote the development, use, and appropriation of modern technologies for the characterization
of marine ecosystems in Colombia. The efforts have been leaded by the Universidad
Pontificia Bolivariana - UPB, the Universidad Nacional de Colombia Sede Medellín -
UNALMED, and the General Maritime Directorate (DIMAR) and its Caribbean Center
for Oceanographic and Hydrographic Research CIOH. Other institutions, such as
Parques Nacionales Naturales de Colombia - PNN, Geomares SAS (a marine surveying
company), Ecopetrol, and Instituto Geográfico Agustín Codazzi have joined the
network through different projects. Such projects have been executed by members
of the network, and are related to the development and use of tools and methods
for the characterization of marine ecosystems by using satellite images, remotely piloted
aircraft systems, high resolution multi-beam bathymetry data, oceanographic
measurements, remotely operated vehicles, gliders, advanced underwater video/
image acquisition systems, geo-referenced diving, and specialized software among
others. The use of such technologies can help producing cartographical data that
will help making informed management decisions. Thus, the ongoing and new projects
are being designed with an inherent emphasis on modern methods that can be
useful for the management of marine ecosystem services and for addressing challenges
related to marine spatial planning processes, such as lack of mechanisms for
stakeholders involvement and enforcement, inadequate technical information, and
limited capacity. Because these modern technologies have not been consistently
used for the integrated characterization of Colombian marine environments, this
inter-institutional effort constitutes one of the first approaches towards the use of
robotics and remote sensing technologies in order to enhance the capacity to document,
understand, manage and protect marine habitats in the country. Using such
technologies to characterize ecosystems (coastal, shallow-water and deep-water)
can help strengthening decision making processes and implement biodiversity conservation
policy to ensure appropriate and sustainable management towards the
achievement of the Sustainable Development Goals in 2030.
Research Interests:
The group of landscape ecology belonging to IUFRO (International Union of Forest Research Organizations) (Unit 8.01.02) and IALE (International Association of Landscape Ecology), in conjunction with the University of La Frontera and the... more
The group of landscape ecology belonging to IUFRO (International Union of Forest Research Organizations)
(Unit 8.01.02) and IALE (International Association of Landscape Ecology), in conjunction with the University
of La Frontera and the Catholic University of Temuco invited to participate Latin American Congress of IUFRO
Landscape Ecology and the Second Latin American Congress of IALE to be held in the city of Temuco
(Province of Cautín, Chile) from November 28 to December 2, 2016, under the theme “Bringing our society to
the nature preserve, manage and restore multi-functional landscapes”. The event’s main objective is to
contribute to the exchange of experiences and knowledge in technical and scientific, methodological and
practical aspects relating to the conservation, management and restoration of natural landscapes throughout
Latin America. It is further intended that this event is a field for institutions, professionals and students interested
in landscape ecology can be linked and interact with current research topics, modern methodologies and policy
implementation.
Research Interests:
Experts in calibration and validation are invited to participate in the Sentinel-2 Validation Team Meeting (S2VT) at ESA-ESRIN in Frascati, Italy. The objective of the S2VT is to collect independent validation evidence and experimental... more
Experts in calibration and validation are invited to participate in the Sentinel-2 Validation Team Meeting (S2VT) at ESA-ESRIN in Frascati, Italy.
The objective of the S2VT is to collect independent validation evidence and experimental data to support the Sentinel-2 mission. The S2VT aims at providing valuable feedback on the mission core products through the experience gained by S2VT members while exploiting Sentinel-2 data. Such recommendations will be taken into consideration by ESA.
In this framework, the S2VT aims at involving world-class expertise and activities, through shared benefit collaboration, that support the implementation of the Sentinel-2 validation activities and ensure the best possible outcomes for the Sentinel-2 mission.
The meeting will be structured around a set of plenary presentations given by expert practitioners working with Sentinel-2 and other similar missions to inform on the lessons learned and priorities based on experience, a poster session of potential cal/val community activities including validation campaigns and methods.
Research Interests:
The present work analyzes the existing relation between the different levels of severity in burns it, obtained from the CBI, and the structure of the landscape, measurement through the texture of satellite images. For it, the field data... more
The present work analyzes the existing relation between the different levels of severity in burns it, obtained from the CBI, and the structure of the landscape, measurement through the texture of satellite images. For it, the field data of a forest fire are used happened the 27 of June of 2003 to the southwest of the Community of Madrid, that was related to acquired images ALI and ASTER after the event. Measures of texture have calculated derived from the matrix of concurrences and the dimension fractal, relating them to the values of the index of severity (CBI) by means of statistical indices of correlation. Finally, the data of the correlation analysis are exposed, that shows a tendency the uniformity in the landscape as the severity level is increased on the vegetation. These increases vary based on the space and spectral resolution, being superior with greater space resolutions and the use of the SWIR that with the IRC. The results of this work show that indices of texture exist very related to the CBI, especially the homogeneity, with values of correlation of up to 0,71 in covers of pino piñonero (Pinus pinaster), and the average, with values that reach the-0,72 in oak covers.