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Evaluating TROPOMI and MODIS performance to capture the dynamic of air pollution in São Paulo state: A case study during the COVID-19 outbreak / A.P. Rudke in Remote sensing of environment, vol 289 (May 2003)  

Public [article]  inRemote sensing of environment > vol 289 (May 2003) . - n° 113514 Titre : Evaluating TROPOMI and MODIS performance to capture the dynamic of air pollution in São Paulo state: A case study during the COVID-19 outbreak Type de document : Article/Communication Auteurs : A.P. Rudke, Auteur ; J.A. Martins, Auteur ; R. Hallak, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 113514 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] correction atmosphérique [Termes IGN] dioxyde d'azote [Termes IGN] épidémie [Termes IGN] image Sentinel-5P-TROPOMI [Termes IGN] image Terra-MODIS [Termes IGN] pollution atmosphérique [Termes IGN] qualité de l'air [Termes IGN] Sao Paulo Résumé : (auteur) Atmospheric pollutant data retrieved through satellite sensors are continually used to assess changes in air quality in the lower atmosphere. During the COVID-19 pandemic, several studies started to use satellite measurements to evaluate changes in air quality in many different regions worldwide. However, although satellite data is continuously validated, it is known that its accuracy may vary between monitored areas, requiring regionalized quality assessments. Thus, this study aimed to evaluate whether satellites could measure changes in the air quality of the state of São Paulo, Brazil, during the COVID-19 outbreak; and to verify the relationship between satellite-based data [Tropospheric NO2 column density and Aerosol Optical Depth (AOD)] and ground-based concentrations [NO2 and particulate material (PM; coarse: PM10 and fine: PM2.5)]. For this purpose, tropospheric NO2 obtained from the TROPOMI sensor and AOD retrieved from MODIS sensor data by using the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm were compared with concentrations obtained from 50 automatic ground monitoring stations. The results showed low correlations between PM and AOD. For PM10, most stations showed correlations lower than 0.2, which were not significant. The results for PM2.5 were similar, but some stations showed good correlations for specific periods (before or during the COVID-19 outbreak). Satellite-based Tropospheric NO2 proved to be a good predictor for NO2 concentrations at ground level. Considering all stations with NO2 measurements, correlations >0.6 were observed, reaching 0.8 for specific stations and periods. In general, it was observed that regions with a more industrialized profile had the best correlations, in contrast with rural areas. In addition, it was observed about 57% reductions in tropospheric NO2 throughout the state of São Paulo during the COVID-19 outbreak. Variations in air pollutants were linked to the region economic vocation, since there were reductions in industrialized areas (at least 50% of the industrialized areas showed >20% decrease in NO2) and increases in areas with farming and livestock characteristics (about 70% of those areas showed increase in NO2). Our results demonstrate that Tropospheric NO2 column densities can serve as good predictors of NO2 concentrations at ground level. For MAIAC-AOD, a weak relationship was observed, requiring the evaluation of other possible predictors to describe the relationship with PM. Thus, it is concluded that regionalized assessment of satellite data accuracy is essential for assertive estimates on a regional/local level. Good quality information retrieved at specific polluted areas does not assure a worldwide use of remote sensor data. Numéro de notice : A2023-170 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1016/j.rse.2023.113514 Date de publication en ligne : 21/02/2023 En ligne : https://doi.org/10.1016/j.rse.2023.113514 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102930 [article]

The effect of intra-urban mobility flows on the spatial heterogeneity of social media activity: investigating the response to rainfall events / Sidgley Camargo de Andrade in International journal of geographical information science IJGIS, vol 36 n° 6 (June 2022)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 36 n° 6 (June 2022) . - pp 1140 - 1165 Titre : The effect of intra-urban mobility flows on the spatial heterogeneity of social media activity: investigating the response to rainfall events Type de document : Article/Communication Auteurs : Sidgley Camargo de Andrade, Auteur ; João Porto de Albuquerque, Auteur ; Camilo Restrepo-Estrada, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 1140 - 1165 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] auto-régression [Termes IGN] distribution spatiale [Termes IGN] données issues des réseaux sociaux [Termes IGN] données socio-économiques [Termes IGN] hétérogénéité spatiale [Termes IGN] mobilité urbaine [Termes IGN] modélisation spatio-temporelle [Termes IGN] pluie [Termes IGN] précipitation [Termes IGN] Sao Paulo [Termes IGN] Twitter Résumé : (auteur) Although it is acknowledged that urban inequalities can lead to biases in the production of social media data, there is a lack of studies which make an assessment of the effects of intra-urban movements in real-world urban analytics applications, based on social media. This study investigates the spatial heterogeneity of social media with regard to the regular intra-urban movements of residents by means of a case study of rainfall-related Twitter activity in São Paulo, Brazil. We apply a spatial autoregressive model that uses population and income as covariates and intra-urban mobility flows as spatial weights to explain the spatial distribution of the social response to rainfall events in Twitter vis-à-vis rainfall radar data. Results show high spatial heterogeneity in the response of social media to rainfall events, which is linked to intra-urban inequalities. Our model performance (R2=0.80) provides evidence that urban mobility flows and socio-economic indicators are significant factors to explain the spatial heterogeneity of thematic spatiotemporal patterns extracted from social media. Therefore, urban analytics research and practice should consider not only the influence of socio-economic profile of neighborhoods but also the spatial interaction introduced by intra-urban mobility flows to account for spatial heterogeneity when using social media data. Numéro de notice : A2022-405 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2021.1957898 Date de publication en ligne : 03/08/2021 En ligne : https://doi.org/10.1080/13658816.2021.1957898 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100717 [article]

An improved rainfall-threshold approach for robust prediction and warning of flood and flash flood hazards / Geraldo Moura Ramos Filho in Natural Hazards, Vol 105 n° 3 (February 2021)  

Public [article]  inNatural Hazards > Vol 105 n° 3 (February 2021) . - pp 2409 - 2429 Titre : An improved rainfall-threshold approach for robust prediction and warning of flood and flash flood hazards Type de document : Article/Communication Auteurs : Geraldo Moura Ramos Filho, Auteur ; Victor Hugo Rabelo Coelho, Auteur ; Emerson da Silva Freitas, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 2409 - 2429 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] crue [Termes IGN] Indice de précipitations antérieures [Termes IGN] indice de risque [Termes IGN] inondation [Termes IGN] méthode robuste [Termes IGN] prévention des risques [Termes IGN] risque naturel [Termes IGN] Sao Paulo [Termes IGN] seuillage [Termes IGN] surveillance hydrologique Résumé : (auteur) This paper presents an improved method of using threshold of peak rainfall intensity for robust flood/flash flood evaluation and warnings in the state of São Paulo, Brazil. The improvements involve the use of two tolerance levels and the delineating of an intermediate threshold by incorporating an exponential curve that relates rainfall intensity and Antecedent Precipitation Index (API). The application of the tolerance levels presents an average increase of 14% in the Probability of Detection (POD) of flood and flash flood occurrences above the upper threshold. Moreover, a considerable exclusion (63%) of non-occurrences of floods and flash floods in between the two thresholds significantly reduce the number of false alarms. The intermediate threshold using the exponential curves also exhibits improvements for almost all time steps of both hydrological hazards, with the best results found for floods correlating 8-h peak intensity and 8 days API, with POD and Positive Predictive Value (PPV) values equal to 81% and 82%, respectively. This study provides strong indications that the new proposed rainfall threshold-based approach can help reduce the uncertainties in predicting the occurrences of floods and flash floods. Numéro de notice : A2020-204 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s11069-020-04405-x Date de publication en ligne : 03/11/2020 En ligne : https://doi.org/10.1007/s11069-020-04405-x Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97167 [article]

Multi‐temporal transport network models for accessibility studies / Diego Bogado Tomasiello in Transactions in GIS, vol 23 n° 2 (April 2019)  

Public [article]  inTransactions in GIS > vol 23 n° 2 (April 2019) . - pp 203 - 223 Titre : Multi‐temporal transport network models for accessibility studies Type de document : Article/Communication Auteurs : Diego Bogado Tomasiello, Auteur ; Mariana Giannotti, Auteur ; Renato Arbex, Auteur ; Clodoveu Davis, Auteur Année de publication : 2019 Article en page(s) : pp 203 - 223 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] accessibilité [Termes IGN] granularité (informatique) [Termes IGN] modèle conceptuel de données spatio-temporelles [Termes IGN] modélisation spatio-temporelle [Termes IGN] réseau de transport [Termes IGN] Sao Paulo [Termes IGN] urbanisme Résumé : (Auteur) Vehicle tracking is a spatio‐temporal source of high‐granularity travel time information that can be used for transportation planning. However, it is still a challenge to combine data from heterogeneous sources into a dynamic transport network, while allowing for network modifications over time. This article uses conceptual modeling to develop multi‐temporal transport networks in geographic information systems (GIS) for accessibility studies. The proposed multi‐temporal network enables accessibility studies with different temporal granularities and from any location inside the city, resulting in a flexible tool for transport and urban planning. The implemented network is tested in two case studies that focus on socially excluded people in a large global city, São Paulo, Brazil, including accessibility analyses from slum areas. It explores variations within a day and differences between transport modes across time. Case study results indicate how the accessibility is heterogeneous in low‐income regions. Numéro de notice : A2019-249 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12513 Date de publication en ligne : 10/03/2019 En ligne : https://doi.org/10.1111/tgis.12513 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93005 [article]

A high resolution orthomosaic in Brazil / N. Parada in Geoinformatics, vol 12 n° 5 (01/07/2009)

Public [article]  inGeoinformatics > vol 12 n° 5 (01/07/2009) . - pp 22 - 26 Titre : A high resolution orthomosaic in Brazil Type de document : Article/Communication Auteurs : N. Parada, Auteur ; U.W. Palme, Auteur ; et al., Auteur Année de publication : 2009 Article en page(s) : pp 22 - 26 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Orthophotographie, orthoimage [Termes IGN] image à très haute résolution [Termes IGN] image Ikonos [Termes IGN] modèle numérique de terrain [Termes IGN] orthophotoplan numérique [Termes IGN] réseau géodésique [Termes IGN] Sao Paulo Résumé : (Auteur) A high orthomosaic was generated for the 800 km area of the country of Campinas, Brazil, derived from Ikonos satellite imagery, a Digital Terrain model (DTM) generated from WorldView-1 satellite imagery, and an implemented geodetic network of 19 points. The final orthomosaic was generated both in normal color and in false color infrared in order to broaden the possible applications to environmental issues. This result represents a very interesting solution to cover large areas in short time and with a lower cost than traditional aerophotogrammetric methods, thus with basically the same quality, allowing for a better assertive planning and sustainable development of the territory. Copyright GEOinformatics Numéro de notice : A2009-280 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29910 [article]

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262-09051	SL	Revue	Centre de documentation	Revues en salle	Disponible

Using neural networks and cellular automata for modelling intra-urban land-use dynamics / C.M. Almeida in International journal of geographical information science IJGIS, vol 22 n° 8-9 (august 2008)  

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GIS and remote sensing as tools for the simulation of urban land-use change / C.M. Almeida in International Journal of Remote Sensing IJRS, vol 26 n° 4 (February 2005)  

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Nouvelle géographie universelle : la Terre et les hommes, 2. Tome 19 Amérique du sud (2ème partie) / Elisée Reclus (1894)

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