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Papers by humberto barbosa

The Journal of the Korea institute of electronic communication sciences, 2019

Sustainability

This study aimed to evaluate the interaction of environmental variables and Water Use Efficiency ... more This study aimed to evaluate the interaction of environmental variables and Water Use Efficiency (WUE) via multivariate analysis to understand the importance of each variable in the carbon–water balance in MATOPIBA. Principal Component Analysis (PCA) was applied to reduce spatial dimensionality and to identify patterns by using the following data: (i) LST (MOD11A2) and WUE (ratio between GPP-MOD17A2 and ET-MOD16A2), based on MODIS orbital products; (ii) Rainfall based on CHIRPS precipitation product; (iii) slope, roughness, and elevation from the GMTED and SRTM version 4.1 products; and (iv) geographic data, Latitude, and Longitude. All calculations were performed in R version 3.6.3 and Quantum GIS (QGIS) version 3.4.6. Eight variables were initially used. After applying the PCA, only four were suitable: Elevation, LST, Rainfall, and WUE, with values greater than 0.7. A positive correlation (≥0.78) between the variables (Elevation, LST, and Rainfall) and vegetation was identified. A...

Sensors, 2022

Remote monitoring platforms based on advanced health sensors have the potential to become importa... more Remote monitoring platforms based on advanced health sensors have the potential to become important tools during the COVID-19 pandemic, supporting the reduction in risks for affected populations such as the elderly. Current commercially available wearable devices still have limitations to deal with heart rate variability (HRV), an important health indicator of human aging. This study analyzes the role of a remote monitoring system designed to support health services to older people during the complete course of the COVID-19 pandemic in Brazil, since its beginning in Brazil in March 2020 until November 2021, based on HRV. Using different levels of analysis and data, we validated HRV parameters by comparing them with reference sensors and tools in HRV measurements. We compared the results obtained for the cardiac modulation data in time domain using samples of 10 elderly people’s HRV data from Fitbit Inspire HR with the results provided by Kubios for the same population using a cardia...

Revista Brasileira de Geografia Física, 2022

Neste estudo foram analisadas as formações vegetais em Angola levando em consideração dois níveis... more Neste estudo foram analisadas as formações vegetais em Angola levando em consideração dois níveis de classificação, o de fitofisionomia (N1) e o de uso e cobertura da terra (N2). Além disso, foi analisado através de parâmetros estatísticos zonais o comportamento da distribuição espacial e temporal da fenologia da vegetação por um período de 18 anos levando em consideração algumas características físicas como o relevo, índices de vegetação (EVI), evapotranspiração normalizada (ETn) e precipitação. As séries temporais foram processadas para se extrair as métricas fenológicas do início, fim e comprimento, taxas de rebrota e senescência da vegetação. Os resultados permitiram observar grande heterogeneidade na representação das métricas fenológicas, pela qual, foi possível caracterizar os diferentes tipos de vegetações. As áreas representadas por vegetação nativa como florestas, savanas e formações de estepes apresentaram maiores áreas se comparadas com as restantes classes como solo exp...

Data used to model satellite-derived Normalized Difference Vegetation Index (NDVI) in response to... more Data used to model satellite-derived Normalized Difference Vegetation Index (NDVI) in response to precipitation on areas of the Brazilian semi-arid Caatinga biome under different protection levels. Variables: cell_id - Numeric ID of the pixel included in the analysis ndvi - Montlhy Normalized Difference Vegetation Index (NDVI) score of the pixel prec - Monhtly precipitation value of the pixel long - Longitude of the pixel centroid lat - Latitude of the pixel centroid protection_type - Catogrical variable indicating the level of land protection in the pixel, including no protection, sustainable use or full protection status

BACKGROUNDCountries have focused research on developing strategies to fight COVID-19, prevent hos... more BACKGROUNDCountries have focused research on developing strategies to fight COVID-19, prevent hospitalizations, and maintain economic activities.OBJECTIVEThis study aimed to establish a survival analysis and identify risk factors for patients with COVID-19 in a upper middle-income city in Brazil.METHODSWe performed a retrospective cohort study with 280 hospitalized patients with COVID-19. The eCOVID platform provided data used to monitor COVID-19 cases and help communication between professionals.RESULTSSurvival analysis showed that age ≥ 65 years was associated with decreased survival (54.8%). Females had lower survival rate than males (p=0.01). Regarding risk factors, urea concentration (p<0.001), hospital LOS (p=0.002), oxygen concentration (p=0.005), and age (p=0.02) were associated with death.CONCLUSIONAge, hospital LOS, high blood urea concentration, and low oxygen concentration were associated with death by COVID-19 in the studied population. These findings corroborate wit...

Abstract. Based on the EUMETSAT/EUMETcast develop research on services, a real-time application t... more Abstract. Based on the EUMETSAT/EUMETcast develop research on services, a real-time application to visualize the weather information during the Brazilian World Cup is presented. This application illustrates the potential of using multimedia systems integrated to Global Earth Observation (GEO) satellite data. EUMETCast is EUMETSAT's primary dissemination mechanism for the near real-time delivery of satellite data and products. Data, products and services are made available via EUMETCast, direct dissemination/readout, the Global Telecommunication System (GTS) and FTP over the internet.The proposed study shows a Web application that uses satellite data from the Meteosat Second Generation (MSG) received by LAPIS EUMETCast station to offer to users a wide visualization of climate data from the host cities of the World Cup held in Brazil. Moreover the developed software can be seen as a visualization layer capable to exhibit satellite images, meteograms, online weather forecast, wind...

On the early morning hours on 1 June 2009, Air France (AF) Flight # 447 descended in to the tropi... more On the early morning hours on 1 June 2009, Air France (AF) Flight # 447 descended in to the tropical Atlantic Ocean at the approximate location of 2°59′N 30°35′W, while en route from Rio de Janeiro, Brazil to

Research, Society and Development, 2021

O estudo tem por objetivos: estimar e analisar as mudanças espaço-temporais da Eficiência do Uso ... more O estudo tem por objetivos: estimar e analisar as mudanças espaço-temporais da Eficiência do Uso da Água (Water Use Efficiency - WUE) no MATOPIBA e avaliar a influência de fatores climáticos e do uso e ocupação do solo na variação do WUE. No estudo serão utilizados os produtos MOD17A2 (GPP) e MOD16A2 (ET) derivados do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) obtidos no United States Geological Survey (USGS), com resolução espacial 1 km x 1km, para as computo da WUE anual no período entre 2001 e 2019. Em relação a avaliação do uso da terra será realizado com as imagens do MAPBIOMAS, com resolução de 30m x 30m. Já os dados de precipitação serão provenientes do Climate Hazard Group InfraRed Precipitation with Station data (CHIRPS) com resolução espacial de 5,6 km por 5,6 km. As realizações dos cálculos matemáticos serão executadas nos softwares ambiente R versão 3.6-3 e Quantum GIS versão 3.4-6. Os resultados apontam que os maiores (menores) valores de WUE ocorrem e...

Frontiers in Earth Science, 2021

Mean monthly Atmospheric Residence Times (ART), deduced from the global climate models of Coupled... more Mean monthly Atmospheric Residence Times (ART), deduced from the global climate models of Coupled Model Intercomparison Project 5 (CMIP5) under RCP4.5 and RCP8.5 emission scenarios over Indian landmass, show a perceptible increase by the end of the 21st century. India, being a tropical country, faces prolonged ART, particularly during the June month of Southwest monsoon season (June to September) which will be an indicative measure of the increased frequency of extreme weather events. Here we show a possible connection of quasi-resonant amplification (QRA) to the recent (August 2018) Kerala heavy rains that resulted in severe floods and claimed more than 400 mortalities. Remarkable delay in residence times over India during June is shown to have an association with QRA evidenced by the higher magnitudes of amplitudes at the wavenumbers six and seven from the 19 global climate models of CMIP5 under the RCP4.5 and RCP8.5 scenarios.

Satellite Information Classification and Interpretation, 2019

Expressive amounts of rainfall may occur during the summer season along all the extension of the ... more Expressive amounts of rainfall may occur during the summer season along all the extension of the mountainous region known as Serra do Mar, which encompasses portions of four states in Brazil – Santa Catarina, Paraná, São Paulo and Rio de Janeiro –, causing landslides and floods. Inter-annual and intra-seasonal oscillations with significant variability in spatial location and range of coverage can be observed, when the phenomenon is analyzed at the appropriate scale. The hazards vary according to geomorphology and land use and the severity of the associated disasters increases with disordered urban occupation. In December 2013 an extremely heavy rainfall occurred over the states of Espírito Santo (ES) and Minas Gerais (MG), killing 45 people and leaving more than 10.000 homeless. These two states are near the region of Serra do Mar forming with it a wider region where the South Atlantic Convergence Zone (SACZ) episodically acts increasing significantly the amount of rainfall during s...

In recent years, there has been increasing interest in remote sensing the temporal dynamics of so... more In recent years, there has been increasing interest in remote sensing the temporal dynamics of soil moisture contents in large agricultural areas, such as those located in the Cattinga biome of the Northeast Brazil (NEB). In this context, validation is critical for accurate and credible satellite-based products usage. The aim of this work is to present the results of the quality assessment of the Surface Soil Moisture (SSM) estimates derived from the microwave sensors on board of the Soil Moisture and Ocean Salinity (SMOS) satellite and the METOP satellite series. Dataset for both platforms are disseminated through the SMOS SSM and ASCAT-SWI operational products, respectively. SMOS SMM and ASCAT-SWI time series were compared to in situ SSM data taken in two sites from the Alagoan semiarid where the Caatinga biome is dominant from February 2012 to October 2013 at a bimonthly time scale. The Spearman’s rho (r), Bias, and Root Mean Square Error (RMSE) were used as statistical metrics. ...

Tecnologia y Ciencias del Agua, 2015

The Valencia lake basin is the endorheic watershed larger of Venezuela (VLB). VLB is densely popu... more The Valencia lake basin is the endorheic watershed larger of Venezuela (VLB). VLB is densely populated and industrialized; therefore the extreme climate even...

A nonanticipative analog method is used for the long-term forecast of air temperature extremes. T... more A nonanticipative analog method is used for the long-term forecast of air temperature extremes. The data to be used for prediction include average daily air temperature, mean visibility, mean wind speed, mean dew point, maximum and minimum temperatures reported during the day from 66 places around the world, as well as sea level, average monthly Darwin and Tahiti sea level pressures, SOI, equatorial SOI, sea surface temperature, and multivariate ENSO index. Every dataset is split into two samples - learning (1973-2010) and validation (2011-2013). Initially, the sum of variables in datasets for two locations, minus corresponding climatological values, is calculated over a summation interval of length from 1 to 365 days. A "quality criterion" selects datasets for two locations with appropriate lead-time and summation interval, which have maximum (or minimum) sum compared with the rest of data four times at least, when extreme events occur later within the learning sample. Up...

The spatial-temporal analysis of the vegetation dynamics (i.e., the response of vegetation to cli... more The spatial-temporal analysis of the vegetation dynamics (i.e., the response of vegetation to climatic conditions) in the semiarid tropical region is important to improve the climate modeling studies in simulating Sea Surface Temperature (SST)-dependent vegetation variability at climatic extremes (Cramer and Fischer, 1996). The Northeast region of Brazil (NEB) is the one such semi-arid tropical region suffering greatest impacts from climatic fluctuations caused by SST anomalies. Although studies have investigated the interannual relationships between SST anomalies and vegetation variations, few have attempted to examine the influence of SST on the semi-arid NEB vegetation during the last two decades of the 20 century. Most of evidence presented by the recent studies on the influence of a strong El Nino-Southern Oscillation (ENSO) event on terrestrial ecosystems of NEB is qualitatively similar to those of the Southern Africa landscape (Azzali and Menenti, 2000). The large variations ...

Revista Brasileira de Geografia Física, 2021

This study evaluates the influence of rainfall, southern oscillation index (SOI), multivariate in... more This study evaluates the influence of rainfall, southern oscillation index (SOI), multivariate index of El Niño Southern Oscillation (ENSO), sea surface temperature anomaly of the sea surface (SSTA) in the Atlantic dipole index and normalized difference vegetation (NDVI/derived from satellites METEOSAT 9 and 10) on agricultural productivity of cane sugar (ton/ha) on the southern coast of the State of Alagoas for the period 2000-2005. Analyses were performed using rainfall Coruripe Plant, located in the municipality of Coruripe/AL. The results show that the annual variability of the agricultural productivity of cane sugar mill Coruripe is modulated largely by rainfall. Additionally, characterized and interannual variability annual agricultural productivity of cane sugar related to climate variability. The results also suggest that the NDVI data from the satellites METEOSAT 9 and 10 used in this work, proved to be, useful observations to characterize the agricultural productivity of c...

Revista Brasileira de Meteorologia, 2020

Resumen El semiárido brasileño frecuentemente se ve afectado por sequías prolongadas. Durante el ... more Resumen El semiárido brasileño frecuentemente se ve afectado por sequías prolongadas. Durante el período 2010-2017, la región semiárida brasileña enfrentó la “sequía del siglo”, considerada la peor registrada en la historia del país. Este artículo tiene como objetivo hacer una evaluación histórica de diferentes fases de las políticas públicas implementadas en la región, con el fin de promover la convivencia con la sequía. Con base en una investigación histórica documental y el monitoreo satelital de los impactos de las sequías, se analizaron las acciones gubernamentales que contribuyeron a brindar una mayor disponibilidad de agua en la región semiárida brasileña, con énfasis en el análisis de la efectividad de la gestión del agua y los impactos de las tecnologías sociales para el almacenamiento del agua de lluvia en comunidades rurales dispersas. Los resultados de la investigación evidenciaron que las políticas implementadas a lo largo de la historia, con frecuencia en un modelo cen...

The Journal of the Korea institute of electronic communication sciences, 2019

Sustainability

Sensors, 2022

Revista Brasileira de Geografia Física, 2022

Research, Society and Development, 2021

Frontiers in Earth Science, 2021

Satellite Information Classification and Interpretation, 2019

Tecnologia y Ciencias del Agua, 2015

Revista Brasileira de Geografia Física, 2021

Revista Brasileira de Meteorologia, 2020

IntechOpen, 2020

At present, satellite rainfall products, such as the Climate Hazards Group InfraRed Precipitation... more At present, satellite rainfall products, such as the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) product, have become an alternative source of rainfall data for regions where rain gauge stations are sparse, e.g., Northeast Brazil (NEB). In this study, continuous scores (i.e., Pearson's correlation coefficient , R; percentage bias, PBIAS; and unbiased root mean square error, ubRMSE) and categorical scores (i.e., probability of detection, POD; false alarm ratio, FAR; and threat score, TS) were used to assess the CHIRPS rainfall estimates against ground-based observations on a pixel-to-station basis, during 01 January 1981 to 30 June 2019 over NEB. Results showed that CHIRPS exhibits better performance in inland regions (R, PBIAS, and ubRMSE median: 0.51, À3.71%, and 9.20 mm/day; POD, FAR, and TS median: 0.59, 0.44, and 0.40, respectively) than near the coast (R, PBIAS, and ubRMSE median: 0.36, À5.66%, and 12.43 mm/day; POD, FAR, and TS median: 0.32, 0.42, and 0.26, respectively). It shows better performance in the wettest months (i.e., DJF) than in the driest months (i.e., JJA) and is sensitive to both the warm-top stratiform cloud systems and the sub-cloud evaporation processes. Overall, the CHIRPS rainfall data set could be used for some operational purposes in NEB.

Northeast Brazil (NEB) is a semi-arid region affected often by severe droughts. It is presumed th... more Northeast Brazil (NEB) is a semi-arid region affected often by severe droughts. It is presumed that the droughts and human impacts could cause an expansion of desertification in the NEB, which would have direct negative implications over ecosystems, water resources, rain-fed agricultural, among other economic activities. However, it is well known that the processes occurring in the vegetation cover are tightly coupled to the processes occurring in components of the climate system. Therefore improve our knowledge about the vegetation response to droughts is of great scientific importance to desertification risk management in the NEB. Unlike previous studies, our goal here is to analyze and to describe the spatial-temporal patterns of vegetation response to severe or extreme droughts in NEB throughout the period of 1982–2013. Varimax-rotated empirical orthogonal function analysis and cluster analysis are applied to the normalized difference vegetation index (NDVI) gridded data from the Advanced Very High Resolution Radiometer in order to reduce its high dimensionality. Standardized precipitation index at 3-months timescale (SPI3) is used as drought index in 18 ground stations located inside of the NEB. We considered that a dry episode occurs when SPI3 ≤1.5 in a station, therefore monthly percentage of stations affected by a dry episode is used as a proxy variable of dry coverage in the NEB. Results show that: i) about 46% of monthly variability of standardized NDVI anomalies in the NEB is explained by 8 dominant spatial-temporal patterns; ii) a dry coverage most persistent than normal in the NEB induces a gradual browning in the vegetation, which is reflected in dominant NDVI patterns; iii) the NEB region seems no to be experiencing a long-term decrease in vegetation greenness, however during the 2012-13 period the vegetation greenness was the most weak of the analyzed period.