Anabella Ferral | Blas Pascal (original) (raw)

Papers by Anabella Ferral

International Journal of Remote Sensing, 2002

Atmospheric correction is an important preprocessing step required in many remote sensing applica... more Atmospheric correction is an important preprocessing step required in many remote sensing applications. The authors are engaged in the project 'Human Dimensions of Amazonia: Forest Regeneration and Landscape Structure' in NASA/INPE's Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) programme. This project requires use of corrected Landsat TM data since research foci integrate ground-based data and TM to: (1) measure and model biomass; (2) classify multiple stages of secondary succession; (3) model land cover/land use changes; and (4) derive spectral signatures consistent across diVerent study areas. The 30+ scenes of TM data are historic and lack detailed atmospheric data needed by physically-based atmospheric correction models such as 6S (Second Simulation of the Satellite Signal in the Solar Spectrum). Imagebased DOS models are based on image measurements and explored in this article for application to LBA study areas. Two methods using theoretical spectral radiance and image acquisition date respectively were used to convert TM DN values to at-satellite radiance. Three image-based models were employed using each method to convert at-satellite radiance to surface re ectance. Analyses of these six diVerent image-based models were conducted. The Improved Imagebased DOS was the best technique for correcting atmospheric eVects in this LBA research with results similar to those obtained from physically-based approaches. l wavelength Gain l radiometric gain Bias l radiometric bias DN l Landsat TM digital number L lsensor apparent at-satellite radiance L lmax maximal spectral radiance at L lrange equal to 255 L lmin minimal spectral radiance at L lrange equal to 0 L lrange range of rescaled radiance, 255 for Landsat 5 TM data G l calibration gain coeYcient DSL l calibration oVset coeYcient

Los compuestos estrogenicos son una clase de productos farmaceuticos nocivos para los animales y ... more Los compuestos estrogenicos son una clase de productos farmaceuticos nocivos para los animales y una de las causas de los danos ambientales. La actividad biologica de estos compuestos es elevada, pues han sido disenados para actuar en bajas concentraciones. Por lo tanto, incluso a las bajas concentraciones en el medio ambiente, pueden producir efectos nocivos sobre los organismos acuaticos, asi como en los humanos, que pudieran estar contaminados en un numero de maneras (a traves de agua potable o alimentos contaminados, por ejemplo). Estudios realizados en cursos superficiales de agua han demostrado una elevada concentracion de estrogenos, esto se debe a que el tratamiento estandar del agua a menudo falla en eliminar el estrogeno y componentes sinteticos quimicamente emparentados con el mismo, o bien el manejo inadecuado de residuos biologicos determina que se viertan a la cuenca fluvial alterando el sistema natural. En este trabajo se estudiara la presencia, origen y concentracion de las tres principales hormonas estrogenicas Esatrona (E1), 17 beta-estradiol (E2) y estriol (E3) en la cuenca del Rio Suquia. El objetivo principal del proyecto es determinar la presencia, concentracion y origen de Estrona (E1), 17 beta-estradiol (E2) y Estriol (E3) en la cuenca del rio Suquia. Sus objetivos especificos son-. Recopilar informacion sobre la presencia y origen de los estrogenos en cuencas hidricas y sus efectos en el ecosistema. Analizar la presencia de estrogenos en la cuenca de Rio Suquia y su variacion estacional. Determinar el posible origen de los estrogenos que esten presentes en la cuenca del Rio Suquia Para cumplimentar con el proyecto se realizaran dos campanas de muestreo durante los peridos mas secos y humedos de la misma en 15 puntos estrategicamente seleccionados, las mismas seran analizadas en laboratorio para determinar la presencia y concentracion de las hormonas estrogenicas Asimismo se realizaran 150 encuestas a mujeres de la ciudad de Cordoba y otras localidades de la cuenca del Rio Suquia a fin de conocer el consumo de pildoras anticonceptivas o la utilizacion de parches anticonceptivos. Se llevaran adelante estudios ambientales que permitan determinar el posible origen en los estrogenos. Se extraeran conclusiones que permitan tener un conocimiento de la presencia, concentracion, origen y variacion estacional de las hormonas estrogenicas, estrona (E1), 17 beta-estradiol (E2) y estriol (E3) en la cuenca del rio Suquia. Los resultados que se esperan es poder determinar la presencia y origen de los tres tipos de estrogenos E1, E2 y E3 en la cuenca del Rio Suquia y poder general informacion que permita a los gobiernos tomar medidas para reducir la contaminacion. HIPOTESIS: "La cuenca del Rio Suquia presenta contaminacion de hormonas estrogenicas"

IEEE Conference Proceedings, 2018

European Scientific Journal, ESJ, Mar 26, 2014

Estrogenic compounds are a class of pharmaceutical products harmful to the animals and a cause of... more Estrogenic compounds are a class of pharmaceutical products harmful to the animals and a cause of environmental damage. The biological activity of these compounds is high, which are designed to operate at low concentrations. Therefore, even in low concentrations in the environment can have harmful effects on aquatic organisms and in humans, who might be consuming water or food contaminated with estrogen. The generic term (estrogen) applies to any substance, natural or synthetic exert biological effects characteristic of ovarian estrogenic hormones, many anabolic and growth promoters in animals, which has led to its misuse in the commercial animal. Estrogen produced in the laboratory can be used as a type of birth control and the treatment of menopausal symptoms, menstrual disorders, osteoporosis and other health treatment. There are three main forms of estrogen found in the human body, Estrone (E1), 17 betaestradiol (E2) and estriol (E3). Estrone (E1) is the most common estrogen in greater quantities in postmenopausal women. Over the last decades, residues of hormones E1, E2 and E3, have been reported mainly in river water and sediments due to the inevitable link to WWTP effluents discharging into the receiving waters In this brief review, we provide an overview of sources, environmental concentrations in surface and ground water, and summarize the current knowledge on fate and behavior of these steroid compounds. And we describe the first sampling campaign (surveys and water samples of the Suquia River) and we present a brief analysis of the surveys.

2020 IEEE Congreso Bienal de Argentina (ARGENCON), 2020

In the central semiarid region of Argentina, the alien woody invasive species modify the water cy... more In the central semiarid region of Argentina, the alien woody invasive species modify the water cycle, reduce biodiversity and alter the nutrient cycles. One of the most important alien woody invasive species is the glossy privet (Ligustrum lucidum W.T. Aiton) with an agressive invasive ability. The objective of this research is to evaluate the NDVI and SAR interferometric coherence time series to discriminate L. lucidum within the native forest matrix in Central Cordoba, Argentina. The time series of interferometric coherence in VH and in VV polarizations and NDVI were plotted and analyzed statistically. Pixel-based classifications with the Random Forest classifier were made. The results show that L. lucidum invaded areas have statistically different differences with the native forest matrix when NDVI and interferometric coherence of C band SAR images, with polarizations VV and VH are analyzed. Also, the Random Forest classifier applied individually on the time series or the combination of them allowed the differentiation between invaded and uninvaded areas. More research should be conducted to evaluate the possibility to integrate temporal series of backscattering, L-band and X-band SAR sensors data, and to test other classifiers.

Zenodo (CERN European Organization for Nuclear Research), Nov 1, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Mapping Human Exposure to Risky Environmental Conditions is key to quantify the vulnerability of ... more Mapping Human Exposure to Risky Environmental Conditions is key to quantify the vulnerability of population and economic assets. In order to develop novel tools, implementing the use of information layers from current and future Earth Observation (EO) missions is necessary. The EOxposure project that has been created and funded by the European Commission's Horizon 2020 research and innovation program covers this porpoise. Several topics involving human exposure to environmental risks are being studied, including water quality and pollution, which is addressed in this paper. The high productivity of biomass registered in eutrophic water bodies, leads to qualitative and quantitative changes in the phytoplankton community, resulting in massive algae blooms. This research work proposes a methodology that takes advantage of the temporal and spectral resolution of Sentinel-2 (S2) for monitoring eutrophic reservoir. Specifically, it uses large temporal series of S2 images and advanced data mining techniques to study the turbid and productive water of San Roque reservoir, Argentina. The spatial patterns and the temporal tendencies of these aquatic indicators are analysed and evaluated in order to assess their contribution to water quality models and a local water management program.

Journal of infectious diseases and epidemiology, Oct 14, 2019

Human Security is a concept instituted by the United Nations and refers to the possibility that e... more Human Security is a concept instituted by the United Nations and refers to the possibility that each person can satisfy basic needs of different kinds: Health, food, environment, education, economy, politics, institutional access, etc. Both WHO and FAO emphasize these concepts related to food and nutritional security (FNS), and relate it to the vulnerability derived from emergency and disaster situations. These are increasingly frequent and complex in a context of climate change, since they affect food systems, directly and indirectly impacting the pillars of FNS: availability, economic access, biological use and sustainability. In this context, the concepts of risk, hazards and vulnerability arise, the latter being determined by exposure, susceptibility and resilience. Managing the concept of vulnerability allows us to approach FNS as an essentially dynamic process. Thus, the objective of the work is to develop and validate an instrument for qualitative-quantitative estimation of the vulnerability of the FNS linked to the threats derived from climate change through its implementation in a pilot test. The variables under study are the FNS, the vulnerability of the FNS, associated with climatic events, and climate hazards. The study is observational, descriptive, and cross-sectional. The instrument was designed based on the Guide for Measuring Food Security prepared by the Red Cross; the WFP Manual for the Evaluation of Food Security in Emergencies and the USDA Food Security Measurement Instrument. The instrument was applied in Cruz del Eje City over 59 citizens and four validation test criteria implemented.

IEEE Latin America Transactions, Feb 1, 2018

The effect of an underwater artificial air diffusion system on the water quality of Embalse San R... more The effect of an underwater artificial air diffusion system on the water quality of Embalse San Roque, Córdoba-Argentine is assessed by means of a temporal-spatial analysis, for 2008-2011, through field data and LANDSAT5-TM satellite imagery. The temperature estimated using TM6 band, resulting with a determination coefficient of 0.94 and a mean square error of 0.4ºC. A multiple regression model was used to calculate the logarithm pf chlorophyll-a concentration by means of TM1 and TM4 bands, obtaining a determination coefficient of 0.64 which was validated with a control group with and agreement of 83%. The processed images show the localized effect of the underwater artificial air diffusion system, improving the water quality in their neighbors.

In Argentina, the deforestation has reached a significant magnitude, particularly in the Chaco Se... more In Argentina, the deforestation has reached a significant magnitude, particularly in the Chaco Serrano area. One of the main consequences of deforestation is the presence of bare soils which are vulnerable to precipitation, where runoff causes flash floods, particularly in the cities crossed by the river in Saldán stream basin, region Sierras Chicas – Córdoba. In this context geospatial techniques allow to quantify the spatial distribution and temporal evolution of prone zones to erosion based on models which incorporate climatic, edaphological, biological and anthropic variables. The RUSLE (Revised Universal Soil Loss Equation) model, calibrated by means of local factors, is used as base methodology to carry out the analysis. The calculation is made by merging satellite, archive and field information. The optical image classifications show a decrease in middle and low stratum of the vegetation cover for the period 2005-2013, a situation that directly impacts the erosion rate of soils close to urban piedmont populations.

Journal of Physical Chemistry B, Jul 7, 2001

We investigated the adsorption of hydronium ions on Ag(111) in conditions that simulate the struc... more We investigated the adsorption of hydronium ions on Ag(111) in conditions that simulate the structure of the double layer using the ab initio quantum mechanical Moller-Plesset second-order method. The most representative points of the potential energy surface for bare hydronium on Ag(111) were first investigated. Then, the ion was hydrated with 1, 2, and 3 water molecules, and the structures of the hydronium-water complexes were studied on Ag(111) under different externally applied homogeneous electric fields. Bare hydronium adsorbs via the hydrogen atoms with C 3V or C s symmetry. For these coordinations, the potential energy surface has a small corrugation: the binding energy on the hcp hollow site (-56 kcal/mol) is only 2 kcal/mol more stable than on the ontop site. On the other hand, adsorption via the oxygen atom is destabilized due to the Pauli repulsion with the metal. The equilibrium geometry of the trihydrated complex (H 9 O 4 +) has the water molecules located between the hydronium ion and the surface, indicating that hydronium does not specifically adsorb. The surface reaction leading to H 9 O 4 + from adsorbed water and hydronium is very exothermic (-32 kcal/mol) mainly due to the formation of hydrogen bonds. The electric field has a smaller influence on the adsorption of the hydrated ion than on the bare ion due to the screening of the water molecules. The different contributions to the binding energy in the presence of electric fields were considered. The polarization contribution is more important for H 9 O 4 + than for H 3 O + and leads to a stabilization of the trihydrated complex at small positive electric fields.

Zenodo (CERN European Organization for Nuclear Research), 2022

Remote sensing community is making enormous efforts to implement early warning systems capable fo... more Remote sensing community is making enormous efforts to implement early warning systems capable for following spatio-temporal patterns of water quality and climate change risk indicators, being Horizon 2030 EOXPOSURE project one of them. This work presents first results of surface temperature Landsat 8 Level 2 Collection 2 products analysis for a reservoir and compare them with field data measurements. A Root Mean Square Error (RMSE) of 1.7 o C and a Mean Absolute Percentage Error (MAPE) of 7% were obtained for these products but validation curve resulted not confident at a 95% level. A semiempirical linear model with 94% accuracy, RMSE of 1.1 o C and a MAPE of 5% is presented. It was successfully validated with a control group data set obtaining 94% accuracy. A Water Surface Temperature temporal series is shown for the 2013-2020 period and spatio temporal patterns are analyzed and discussed. Water surface temperature behavior in zones with algal bloom occurrence present greater significant values, up to 3 o C, than those with clearer water, indicating that water emissitiviy must be revised for these cases.

Extensive eutrophication process in water body may lead to the creation of algal blooms, reductio... more Extensive eutrophication process in water body may lead to the creation of algal blooms, reduction in oxygen supplies, death of aquatic life and danger to human health. Monitoring eutrophic processes is therefore mandatory to the aquatic environment and human health. However, the changes in the spatial and seasonal distribution of the phenomena are difficult to be resolved using sparse water sampling or acquisition of remote sensing data. Therefore, this research work proposes a methodology that takes advantage of the temporal and spectral resolution of Sentinel-2 (S2) for monitoring eutrophic reservoir. Specifically, it uses large temporal series of S2 images and advanced temporal unmixing model to study the spectral response of the turbid and productive water of San Roque reservoir, Argentina. The spatial patterns and the temporal tendencies of these aquatic indicators are analysed and evaluated in order to assess their contribution to the local water management.

Hydrological Sciences Journal-journal Des Sciences Hydrologiques, Nov 25, 2020

Water temperature is fundamental to understand the functioning of aquatic systems. The objective ... more Water temperature is fundamental to understand the functioning of aquatic systems. The objective of this study was to assess the effect of warm water discharge from a nuclear power plant on the water surface temperature (WST) of a reservoir. Using a 6-year Landsat-derived WST dataset, which includes 3 years of the power plant being in operation (2013-2015) and 3 years in which the power plant was not functioning (2016-2018), the effect of the thermal pollution was assessed. The results show that, although the warm water discharge did not reveal a statistically significant increase on the mean WST of the reservoir (p > 0.05), multi-temporal Landsat imagery revealed that the power plant generated a local thermal impact. This was the principal heat flux following a dissipation line that was wide near the cooling channel and expanding towards the rest of the reservoir.

Eutrophication is a phenomenon that affects many water bodies around the world. San Roque Dam is ... more Eutrophication is a phenomenon that affects many water bodies around the world. San Roque Dam is not an exception since it has been going through a huge increase in algae concentration. In this framework, its monitoring is a key matter, as is the source of water supply most important of Cordoba city. Remote sensing is a fundamental tool to complement traditional in situ monitoring and understand processes that occur in the reservoir. This study presents a semi-empirical algorithm obtained from MODIS data and in situ chlorophyll-a measurements, provided by the Ministry of Water Resources of Cordoba Province. From this model, a daily time chlorophyll-a time series was obtained from 2001 to 2014. Statistical analysis of the series indicate that water quality of the reservoir has worsened when comparing sets of last (2014–2010) and first (2010–2014) five years.

Eutrophication is a process in which elevated organic matter and nutrients raises the primary pro... more Eutrophication is a process in which elevated organic matter and nutrients raises the primary production of a water body. As a result, the productivity of phytoplankton and biomass are very high at all trophic levels. During bloom event, the spatial and temporal distribution of this phenomena is difficult to be observed using conventional water sampling methods. This work advance the state of the art by using Sentinel-2 (S2) images to estimate chlorophyll-a (chl-a) concentration with an empirical model. Specifically, the model uses band 8 (NIR) and band 4 (red) to predict chl-a concentration during an algal bloom event in San Roque lake, Córdoba, Argentina. Nevertheless, novel spectral ratio for algae composition patterns has also been created using bands 8a and 9. The results show that S2 has the potential to monitor bloom events in eutrophic lakes.

International Journal of Remote Sensing, 2002

IEEE Conference Proceedings, 2018

European Scientific Journal, ESJ, Mar 26, 2014

2020 IEEE Congreso Bienal de Argentina (ARGENCON), 2020

Zenodo (CERN European Organization for Nuclear Research), Nov 1, 2021

Journal of infectious diseases and epidemiology, Oct 14, 2019

IEEE Latin America Transactions, Feb 1, 2018

Journal of Physical Chemistry B, Jul 7, 2001

Zenodo (CERN European Organization for Nuclear Research), 2022

Hydrological Sciences Journal-journal Des Sciences Hydrologiques, Nov 25, 2020

— Global climate change has different demonstrable effects on ecosystem structures and socioecono... more — Global climate change has different demonstrable effects on ecosystem structures and socioeconomic factors throughout the entire planet. 90 percent of last decade natural hazards around the world were attributed to water-related disasters. Forest-land use change, deforestation, unplanned urbanization, localization of marginal population groups in vulnerable areas, wild fires, high temperatures, unusual precipitations, among others are some of the variables that increase the probability of a water-related catastrophe. Comprehensive hazard assessments and appropriated environmental policies orientated towards risk management complemented with planning and designing of hydraulic infrastructures may contribute to decrease flash flooding risk a well as the magnitude of the potential damages. The aim of this study is to develop a consistent methodology to determine the vulnerability, threat and risk of mountain urban areas that are particularly vulnerable to the effects of heavy, rapid rains and represent the obtained results in a risk map. Identifying risk prone areas can be achieved by adapting geological-geotechnical charts, hydrological models, field inventories and official census data from the town of Unquillo, in the province of Cordoba, Argentina. The analytic hierarchy process was used in order to determine the individual contribution of each vulnerability factor, together with geographical information systems used to combine the obtained information trough algebra and transformation of satellite imagery bands. The case of study show that 59% of the total flooding vulnerability relates to the buildings infrastructure, followed by the social factors which represent 33% of the total vulnerability equation. The threat map was validated using landmarks and remains obtained as a consequence of the flooding that occurred on February 15th 2015 in the study area.

Eutrophication is a phenomenon that affects many water bodies around the world. In severe cases, ... more Eutrophication is a phenomenon that affects many water bodies around the world. In severe cases, eutrophication can lead to large algal blooms. This study presents a method to detect algae blooms based on a time series of chlorophyll-a (Chl-a) concentration in the period 2001-2014. This time series is obtained from a semi-empirical algorithm generated with MODIS satellite data and in situ data from the Ministry of Water Resources of Cordoba Province. By detecting algae bloom dates and their statistic characterization, it is possible to define the range of Chl-a values in which the San Roque Dam is going through a bloom event.

Mountain glaciers are important because they work as precipitation buffers and water sources fo... more Mountain glaciers are important because they work as precipitation buffers and water sources for downstream populations. In addition, they have been a source of data for climate dynamics analysis. Measuring glaciers meteorological variables, estimating the amount of black carbon, as well as recording mass slides on a periodic basis becomes mandatory to understand and drive effective environmental policies. While these measurements are traditionally executed via expensive field campaigns, they tend to be scarce and non-periodic. Thus, remote sensing alternatives have been explored by the community, they are based in monolithic satellite architectures which besides the long development time, are bounded in mission lifetime. In this paper we propose a Glacier Segmented Observation System (SOS), based on a number of interconnected cubesats under the segmented architecture paradigm to provide frequent revisit times and extendable lifetime for critical observation missions. We evaluate how SOS can support a worldwide glacier remote sensing mission to then discuss relevant mission requirements, formation flying disposition of satellites and communication architecture challenges.

Remote Sensing Applications: Society and Environment, 2019

The protection and restoration of water-related ecosystems is one of the goals to be achieved by ... more The protection and restoration of water-related ecosystems is one of the goals to be achieved by the United Nations' 2030 Agenda for Sustainable Development. In this framework and requested by government Argentine institutions concerned with water, biodiversity and territorial management, this study analyzes the evolution of the flooded area within the Dulce River wetlands and Mar Chiquita Lake Nature Reserve (centered around 30.6°S, 62.6°W, 70 m above sea level) in Argentina since 2003, when the historical maximum extent was reached, until 2017. The Modified Normalized Difference Water Index (MNDWI) was calculated on atmospherically corrected NASA Landsat 5 Thematic Mapper (L5-TM) and Landsat 8 Operational Land Imager (L8-OLI) reflectance data over two-scene cloudless-sky mosaics to cover the whole Reserve. Mixed-water pixels constituted an important fraction of the total-water covered area, particularly during years of minimum water level in Mar Chiquita Lake. So, MNDWI values were analyzed along transects crossing two stable regional water bodies to determine precise thresholds for detection of non-water (MNDWI < −0.15 for L5-TM, MNDWI < −0.35 for L8-OLI), mixed-water (−0.15 < MNDWI < 0.4 for L5-TM, −0.35 < MNDWI < 0.5 for L8-OLI) and open-water (0.4 < MNDWI for L5-TM, 0.5 < MNDWI for L8-OLI) pixels. A higher spatial resolution image, SPOT5-HGR2, was used to validate the classification method. A confusion matrix was built which resulted in an overall accuracy of 99.2% and a Kappa coefficient of 0.98. In-situ Geo-referenced photographic registers were also taken simultaneously to a Landsat 8 overpass to confirm the classification thresholds. The analysis of simulated MNDWI response, by using the assumption of the linear mixture model, showed that mixed pixels should present from 9% to 76% of detectable open-water area. Maximum total flooded area extensions of about 3600 km 2 by 2003-2005 and a minimum one of 2050 km 2 by the end of 2011 were established, followed by a recent trend to the recovering with a total flooded area of about 3400 km 2 in the period 2015-2017. Open-water covered area follows closely the behavior of in-situ water level measurements of Mar Chiquita Lake, showing a maximum in year 2003 and a minimum towards the end of 2013, in a significant linear relation from which a topographical slope of the terrain of about 0.012% is inferred that agrees with previous bathymetric studies. Results show the powerful complement between a reliable water satellite monitoring tool and locally-measured parameters in so dynamic wetland regions.