Human-caused forest fires have increased in magnitude and frequency, affecting global vegetation and requiring a re-evaluation of fire regimes. Changing fire regimes have led to reduced burned areas in fire- dependent ecosystems and increased areas in fire-independent ecosystems, resulting in changes in land cover and posing a threat to native plant communities. This study focuses on monitoring vegetation recovery after fires in California, USA, using the Enhanced Vegetation Index (EVI) from MODIS time series. The goal is to determine the full recovery time and half recovery time (HRT) after forest fires in year 2017 and analyze the influence of burn severity on three land cover classes in two different climate zones in California.Analyzes show that the "Closed Forest" land cover type exhibits the longest recovery period, followed by the "Open Forest" type and “Herbaceous/Shrub” type in both climate zones but no general connection between recovery time and climate zone was observed. It is found that burn severity degree affects HRT but not the full recovery time in both Mediterranean and Semi-arid climate zones. The study mainly highlights the variations in forest fire recovery patterns between land cover types, as well as differences observed between climate zones.

Uma das atividades mais relevantes para a economia brasileira é a agricultura. Entre os produtos de maior importância no cenário agrícola nacional, estão a soja e o arroz, os quais representam uma grande parcela da produção. Somente o Estado do Rio Grande do Sul é responsável por aproximadamente 67% da produção nacional de arroz e 10% de soja (IBGE, 2012). Portanto, informações confiáveis sobre a produção agrícola são relevantes para o desenvolvimento do setor e o desenvolvimento de metodologias capazes de auxiliar no monitoramento das áreas agrícolas torna-se peça importante na geração de dados confiáveis e com maior rapidez de obtenção. Desta forma, o objetivo deste trabalho foi desenvolver uma metodologia de baixo custo para a execução do mapeamento da área cultivada de arroz irrigado e soja, em escala municipal e estadual, baseado na análise do comportamento espectro-temporal de índices de vegetação de imagens de satélite de alta resolução temporal. O estudo foi realizado no Estado do Rio Grande do Sul, abrangendo os 497 municípios no ano safra 2011/2012. Para realizar o estudo, foram utilizadas imagens multitemporais do sensor MODIS, índices de vegetação EVI e NDVI. Foi aplicado o modelo HAND para gerar as áreas de inundação, as quais foram utilizadas para discriminar a cultura do arroz irrigado de outras culturas, especialmente a soja. Para avaliar os resultados foram utilizados como dados de referência, os dados coletados a campo, dados de área cultivada do IBGE e dados do mapeamento gerados a partir de imagens do satélite RapidEye. Os resultados mostraram que a metodologia proposta foi satisfatória, com valores médios do índice Kappa de 0,90 para a cultura de arroz irrigado e de 0,84 para a soja. Não houve diferença significativa entre as estimativas de área cultivada utilizando os dados EVI e NDVI para ambas as culturas. A utilização do Modelo HAND para discriminar o arroz irrigado de outros cultivos, mostrou-se muito eficiente, separando as áreas de várzea, que são mais aptas para o cultivo de arroz irrigado. Apesar dos resultados terem sido considerados como satisfatórios alguns municípios apresentaram problemas de subestimação ou superestimação quando foram comparados com os dados oficiais do IBGE. Esses problemas podem estar relacionados ao caráter subjetivo de aquisição de dados por parte do IBGE e também o fato de ter sido utilizada para a validação dos dados da safra 2011/2012 a média das últimas três safras, podendo desta maneira ter fragilizado ou comprometido os resultados para alguns municípios. Portanto, técnicas de sensoriamento remoto e geoprocessamento podem ser úteis no auxilio dos atuais métodos de monitoramento e mapeamento de culturas agrícolas, melhorando as estatísticas oficiais do arroz irrigado e soja. / One of the most relevant activities for the Brazilian economy is agriculture. Among the products of greatest importance in the national agricultural, are soybeans and rice, which represent a large portion of the production. Only the State of Rio Grande do Sul is responsible for approximately 67% of the national rice production and 10% of soybean (IBGE, 2012). Therefore, reliable information on agricultural production are relevant to the development of the sector and the development of methodologies capable of assist in the monitoring of agricultural areas becomes important part in the generation of reliable data and faster of obtaining. Thus, the objective of this work was to develop a methodology of low cost to implement the mapping of acreage irrigated rice and soybeans, at the municipal and state levels, based on the analysis of the spectral-temporal behavior of vegetation indices from satellite images high temporal resolution. The study was conducted in the state of Rio Grande do Sul, covering 497 municipalities in crop year 2011/2012. To conduct the study, images were used multitemporal MODIS vegetation indices EVI and NDVI. HAND model was applied to generate the inundation areas, which were used to discriminate the rice culture of other crops, especially soybeans. To evaluate the results were used as reference data, data collected in the field, the cultivated area data from the IBGE and mapping data generated from satellite images RapidEye. The results show that the proposed method was satisfactory, with mean values of Kappa 0.90 for irrigated rice and 0.84 for soybeans. There was no significant difference between the estimates of acreage using EVI and NDVI data for both crops. The use of the HAND model to discriminate irrigated rice from other crops, was very efficient, separating the lowland areas, which are more suitable for the cultivation of irrigated rice. Although the results were considered satisfactory as some municipalities had problems underestimation or overestimation when they were compared with the official data. These problems may be related to the subjective nature of data acquisition by the IBGE and the fact of having been used for the validation of data from 2011/2012 season the average of the last three years, and may in this way be weakened or compromised results for some municipalities. Therefore, techniques of remote sensing and GIS can be useful in the aid of the current methods of monitoring and mapping of agricultural crops, improving the official statistics of irrigated rice and soybeans.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T23:18:28Z No. of bitstreams: 1 KionaraSarabellaTuribioESilva_DISSERT.pdf: 1524779 bytes, checksum: a034505b357fab3aef4e1f83a7bbc3d6 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-18T19:54:55Z (GMT) No. of bitstreams: 1 KionaraSarabellaTuribioESilva_DISSERT.pdf: 1524779 bytes, checksum: a034505b357fab3aef4e1f83a7bbc3d6 (MD5) / Made available in DSpace on 2016-05-18T19:54:55Z (GMT). No. of bitstreams: 1 KionaraSarabellaTuribioESilva_DISSERT.pdf: 1524779 bytes, checksum: a034505b357fab3aef4e1f83a7bbc3d6 (MD5) Previous issue date: 2015-06-15 / O bioma Caatinga, ecossistema de clima semi?rido localizado no nordeste do Brasil, apresenta forte sazonalidade com baixo regime de precipita??o. Esta regi?o possui as proje??es de mudan?as clim?ticas mais alarmantes do pa?s, com o aumento temperatura do ar e a redu??o da pluviosidade com tend?ncias mais fortes que as previs?es m?dias globais. As mudan?as clim?ticas no bioma podem acarretar na diminui??o da cobertura vegetal e altera??o de sua distribui??o, bem como do funcionamento ecossist?mico. Desta forma, influencia fortemente na diversidade de esp?cies. Nesse contexto, a proposta desse estudo ? modelar a din?mica da vegeta??o em fun??o das condi??es ambientais (pluviosidade e temperatura), bem como predizer as consequ?ncias das mudan?as clim?ticas, baseadas nesses determinantes ambientais para o verdor da vegeta??o. O ?ndice de vegeta??o EVI (Enhanced Vegetation Index) foi usado para estimar o verdor da vegeta??o no bioma. A fim de considerar a forte autocorrrela??o temporal e espacial, bem como a heterogeneidade presente nos dados, v?rios modelos GLS (Generalized Least Squares) foram desenvolvidos e comparados para se obter o melhor modelo. Tal modelo refletiu a influ?ncias das condi??es ambientais na previs?o do verdor da vegeta??o no futuro. Diante da aplica??o dos novos cen?rios de mudan?as clim?ticas no modelo, a modifica??o dos determinantes ambientais, pluviosidade e temperatura, influenciou negativamente no verdor da vegeta??o no bioma Caatinga. Esse modelo foi usado para criar imagens de vegeta??o potencial nos per?odos presente e futuro do bioma Caatinga considerando que at? 2040 haver? uma diminui??o de 20% da precipita??o e um aumento de 1?C na temperatura; at? 2070 haver? uma diminui??o de 35% na precipita??o e um aumento de 2,5?C na temperatura; e at? o final do s?culo o percentual de diminui??o das chuvas alcan?ar? 50% e a temperatura ter? um aumento de at? 4,5?C. Os resultados desse estudo sugerem que o funcionamento do ecossistema ser? afetado com a diminui??o de 5,9% do verdor da vegeta??o at? 2040, 14,2% at? 2070 e 24,3 % at? o final do s?culo. A vegeta??o da Caatinga em ?reas de baixa altitude (maior parte do bioma) ser? mais afetada pelas mudan?as clim?ticas. / The Caatinga biome, a semi-arid climate ecosystem found in northeast Brazil, presents low rainfall regime and strong seasonality. It has the most alarming climate change projections within the country, with air temperature rising and rainfall reduction with stronger trends than the global average predictions. Climate change can present detrimental results in this biome, reducing vegetation cover and changing its distribution, as well as altering all ecosystem functioning and finally influencing species diversity. In this context, the purpose of this study is to model the environmental conditions (rainfall and temperature) that influence the Caatinga biome productivity and to predict the consequences of environmental conditions in the vegetation dynamics under future climate change scenarios. Enhanced Vegetation Index (EVI) was used to estimate vegetation greenness (presence and density) in the area. Considering the strong spatial and temporal autocorrelation as well as the heterogeneity of the data, various GLS models were developed and compared to obtain the best model that would reflect rainfall and temperature influence on vegetation greenness. Applying new climate change scenarios in the model, environmental determinants modification, rainfall and temperature, negatively influenced vegetation greenness in the Caatinga biome. This model was used to create potential vegetation maps for current and future of Caatinga cover considering 20% decrease in precipitation and 1 ?C increase in temperature until 2040, 35% decrease in precipitation and 2.5 ?C increase in temperature in the period 2041-2070 and 50% decrease in precipitation and 4.5 ?C increase in temperature in the period 2071-2100. The results suggest that the ecosystem functioning will be affected on the future scenario of climate change with a decrease of 5.9% of the vegetation greenness until 2040, 14.2% until 2070 and 24.3% by the end of the century. The Caatinga vegetation in lower altitude areas (most of the biome) will be more affected by climatic changes.

Uma das atividades mais relevantes para a economia brasileira é a agricultura. Entre os produtos de maior importância no cenário agrícola nacional, estão a soja e o arroz, os quais representam uma grande parcela da produção. Somente o Estado do Rio Grande do Sul é responsável por aproximadamente 67% da produção nacional de arroz e 10% de soja (IBGE, 2012). Portanto, informações confiáveis sobre a produção agrícola são relevantes para o desenvolvimento do setor e o desenvolvimento de metodologias capazes de auxiliar no monitoramento das áreas agrícolas torna-se peça importante na geração de dados confiáveis e com maior rapidez de obtenção. Desta forma, o objetivo deste trabalho foi desenvolver uma metodologia de baixo custo para a execução do mapeamento da área cultivada de arroz irrigado e soja, em escala municipal e estadual, baseado na análise do comportamento espectro-temporal de índices de vegetação de imagens de satélite de alta resolução temporal. O estudo foi realizado no Estado do Rio Grande do Sul, abrangendo os 497 municípios no ano safra 2011/2012. Para realizar o estudo, foram utilizadas imagens multitemporais do sensor MODIS, índices de vegetação EVI e NDVI. Foi aplicado o modelo HAND para gerar as áreas de inundação, as quais foram utilizadas para discriminar a cultura do arroz irrigado de outras culturas, especialmente a soja. Para avaliar os resultados foram utilizados como dados de referência, os dados coletados a campo, dados de área cultivada do IBGE e dados do mapeamento gerados a partir de imagens do satélite RapidEye. Os resultados mostraram que a metodologia proposta foi satisfatória, com valores médios do índice Kappa de 0,90 para a cultura de arroz irrigado e de 0,84 para a soja. Não houve diferença significativa entre as estimativas de área cultivada utilizando os dados EVI e NDVI para ambas as culturas. A utilização do Modelo HAND para discriminar o arroz irrigado de outros cultivos, mostrou-se muito eficiente, separando as áreas de várzea, que são mais aptas para o cultivo de arroz irrigado. Apesar dos resultados terem sido considerados como satisfatórios alguns municípios apresentaram problemas de subestimação ou superestimação quando foram comparados com os dados oficiais do IBGE. Esses problemas podem estar relacionados ao caráter subjetivo de aquisição de dados por parte do IBGE e também o fato de ter sido utilizada para a validação dos dados da safra 2011/2012 a média das últimas três safras, podendo desta maneira ter fragilizado ou comprometido os resultados para alguns municípios. Portanto, técnicas de sensoriamento remoto e geoprocessamento podem ser úteis no auxilio dos atuais métodos de monitoramento e mapeamento de culturas agrícolas, melhorando as estatísticas oficiais do arroz irrigado e soja. / One of the most relevant activities for the Brazilian economy is agriculture. Among the products of greatest importance in the national agricultural, are soybeans and rice, which represent a large portion of the production. Only the State of Rio Grande do Sul is responsible for approximately 67% of the national rice production and 10% of soybean (IBGE, 2012). Therefore, reliable information on agricultural production are relevant to the development of the sector and the development of methodologies capable of assist in the monitoring of agricultural areas becomes important part in the generation of reliable data and faster of obtaining. Thus, the objective of this work was to develop a methodology of low cost to implement the mapping of acreage irrigated rice and soybeans, at the municipal and state levels, based on the analysis of the spectral-temporal behavior of vegetation indices from satellite images high temporal resolution. The study was conducted in the state of Rio Grande do Sul, covering 497 municipalities in crop year 2011/2012. To conduct the study, images were used multitemporal MODIS vegetation indices EVI and NDVI. HAND model was applied to generate the inundation areas, which were used to discriminate the rice culture of other crops, especially soybeans. To evaluate the results were used as reference data, data collected in the field, the cultivated area data from the IBGE and mapping data generated from satellite images RapidEye. The results show that the proposed method was satisfactory, with mean values of Kappa 0.90 for irrigated rice and 0.84 for soybeans. There was no significant difference between the estimates of acreage using EVI and NDVI data for both crops. The use of the HAND model to discriminate irrigated rice from other crops, was very efficient, separating the lowland areas, which are more suitable for the cultivation of irrigated rice. Although the results were considered satisfactory as some municipalities had problems underestimation or overestimation when they were compared with the official data. These problems may be related to the subjective nature of data acquisition by the IBGE and the fact of having been used for the validation of data from 2011/2012 season the average of the last three years, and may in this way be weakened or compromised results for some municipalities. Therefore, techniques of remote sensing and GIS can be useful in the aid of the current methods of monitoring and mapping of agricultural crops, improving the official statistics of irrigated rice and soybeans.

Uma das atividades mais relevantes para a economia brasileira é a agricultura. Entre os produtos de maior importância no cenário agrícola nacional, estão a soja e o arroz, os quais representam uma grande parcela da produção. Somente o Estado do Rio Grande do Sul é responsável por aproximadamente 67% da produção nacional de arroz e 10% de soja (IBGE, 2012). Portanto, informações confiáveis sobre a produção agrícola são relevantes para o desenvolvimento do setor e o desenvolvimento de metodologias capazes de auxiliar no monitoramento das áreas agrícolas torna-se peça importante na geração de dados confiáveis e com maior rapidez de obtenção. Desta forma, o objetivo deste trabalho foi desenvolver uma metodologia de baixo custo para a execução do mapeamento da área cultivada de arroz irrigado e soja, em escala municipal e estadual, baseado na análise do comportamento espectro-temporal de índices de vegetação de imagens de satélite de alta resolução temporal. O estudo foi realizado no Estado do Rio Grande do Sul, abrangendo os 497 municípios no ano safra 2011/2012. Para realizar o estudo, foram utilizadas imagens multitemporais do sensor MODIS, índices de vegetação EVI e NDVI. Foi aplicado o modelo HAND para gerar as áreas de inundação, as quais foram utilizadas para discriminar a cultura do arroz irrigado de outras culturas, especialmente a soja. Para avaliar os resultados foram utilizados como dados de referência, os dados coletados a campo, dados de área cultivada do IBGE e dados do mapeamento gerados a partir de imagens do satélite RapidEye. Os resultados mostraram que a metodologia proposta foi satisfatória, com valores médios do índice Kappa de 0,90 para a cultura de arroz irrigado e de 0,84 para a soja. Não houve diferença significativa entre as estimativas de área cultivada utilizando os dados EVI e NDVI para ambas as culturas. A utilização do Modelo HAND para discriminar o arroz irrigado de outros cultivos, mostrou-se muito eficiente, separando as áreas de várzea, que são mais aptas para o cultivo de arroz irrigado. Apesar dos resultados terem sido considerados como satisfatórios alguns municípios apresentaram problemas de subestimação ou superestimação quando foram comparados com os dados oficiais do IBGE. Esses problemas podem estar relacionados ao caráter subjetivo de aquisição de dados por parte do IBGE e também o fato de ter sido utilizada para a validação dos dados da safra 2011/2012 a média das últimas três safras, podendo desta maneira ter fragilizado ou comprometido os resultados para alguns municípios. Portanto, técnicas de sensoriamento remoto e geoprocessamento podem ser úteis no auxilio dos atuais métodos de monitoramento e mapeamento de culturas agrícolas, melhorando as estatísticas oficiais do arroz irrigado e soja. / One of the most relevant activities for the Brazilian economy is agriculture. Among the products of greatest importance in the national agricultural, are soybeans and rice, which represent a large portion of the production. Only the State of Rio Grande do Sul is responsible for approximately 67% of the national rice production and 10% of soybean (IBGE, 2012). Therefore, reliable information on agricultural production are relevant to the development of the sector and the development of methodologies capable of assist in the monitoring of agricultural areas becomes important part in the generation of reliable data and faster of obtaining. Thus, the objective of this work was to develop a methodology of low cost to implement the mapping of acreage irrigated rice and soybeans, at the municipal and state levels, based on the analysis of the spectral-temporal behavior of vegetation indices from satellite images high temporal resolution. The study was conducted in the state of Rio Grande do Sul, covering 497 municipalities in crop year 2011/2012. To conduct the study, images were used multitemporal MODIS vegetation indices EVI and NDVI. HAND model was applied to generate the inundation areas, which were used to discriminate the rice culture of other crops, especially soybeans. To evaluate the results were used as reference data, data collected in the field, the cultivated area data from the IBGE and mapping data generated from satellite images RapidEye. The results show that the proposed method was satisfactory, with mean values of Kappa 0.90 for irrigated rice and 0.84 for soybeans. There was no significant difference between the estimates of acreage using EVI and NDVI data for both crops. The use of the HAND model to discriminate irrigated rice from other crops, was very efficient, separating the lowland areas, which are more suitable for the cultivation of irrigated rice. Although the results were considered satisfactory as some municipalities had problems underestimation or overestimation when they were compared with the official data. These problems may be related to the subjective nature of data acquisition by the IBGE and the fact of having been used for the validation of data from 2011/2012 season the average of the last three years, and may in this way be weakened or compromised results for some municipalities. Therefore, techniques of remote sensing and GIS can be useful in the aid of the current methods of monitoring and mapping of agricultural crops, improving the official statistics of irrigated rice and soybeans.

Agriculture and food security are interlinked. New technologies and instruments are making the agricultural system easy to operate and increasing the food production. Remote sensing technology is widely used as a non-destructive method for crop growth monitoring, climate analysis, and forecasting crop yield. The objectives of this study are to (1) monitor crop growth remotely, (2) identify climate impacts on crop yield, and (3) forecasting crop yield. This study proposed methods to improve crop growth monitoring and yield predictions by using remote sensing technology. In this study, we developed crop vegetative growth metrics (VGM) from the MODIS (Moderate Resolution Imaging Spectroradiometer) 250m NDVI (Normalized Difference Vegetation Index) and EVI (Enhanced Vegetation Index) data. We developed 19 NDVI and EVI based VGM metrics for soybean crop from a time series of 2000 to 2018, but the methods are applicable to other crops as well. We found VGMmax, VGM70, VGM85, VGM98T are about 95% crop yield predictable. However, these metrics are independent of climatic events. We modelled the climatic impacts on soybean crop from the time series data from1980-2019 collected from NOAA's National Climatic Data Center (NCDC). Therefore, we estimated the impacts of increase and decrease of temperature (maximum, mean, and minimum) and precipitation (average) pattern on crop yields which will be helpful to monitor climate change impacts on crop production. Lastly, we made crop yield forecasting statistical model across different climatic regions in USA using Google Earth Engine. We used remotely sensed MODIS Terra surface reflectance 8-day global 250m data to calculate VGM metrics (e.g. VGM70, VGM85, VGM98T, VGM120, VGMmean, and VGMmax), MODIS Terra land surface temperature and Emissivity 8-Day data for average day-time and night-time temperature and CHIRPS (Climate Hazards Group Infra-red Precipitation with station data) data for precipitation, from a time series data of 2000-2019. Our predicted models showed a NMPE (Normalized Mean Prediction error) with in a range of -0.002 to 0.007. These models will be helpful to get an overall estimate of crop production and aid in national agricultural strategic planning. Overall, this study will benefit farmers, researchers, and management system of U.S. Department of Agriculture (USDA).

In the southwest United States, the current prolonged warm drought is similar to the predicted future climate change scenarios for the region. This study aimed to determine patterns in vegetation response to the early 21st century drought across multiple biomes. We hypothesized that different biomes (forests, shrublands, and grasslands) would have different relative sensitivities to both climate drivers (precipitation and temperature) and legacy effects (previous-year's productivity). We tested this hypothesis at eight Ameriflux sites in various Southwest biomes using NASA Moderate-resolution Imaging Spectroradiometer Enhanced Vegetation Index (EVI) from 2001 to 2013. All sites experienced prolonged dry conditions during the study period. The impact of combined precipitation and temperature on Southwest ecosystems at both annual and sub-annual timescales was tested using Standardized Precipitation Evapotranspiration Index (SPEI). All biomes studied had critical sub-annual climate periods during which precipitation and temperature influenced production. In forests, annual peak greenness (EVImax) was best predicted by 9-month SPEI calculated in July (i.e., January-July). In shrublands and grasslands, EVImax was best predicted by SPEI in July through September, with little effect of the previous year's EVImax. Daily gross ecosystem production (GEP) derived from flux tower data yielded further insights into the complex interplay between precipitation and temperature. In forests, GEP was driven by cool-season precipitation and constrained by warm-season maximum temperature. GEP in both shrublands and grasslands was driven by summer precipitation and constrained by high daily summer maximum temperatures. In grasslands, there was a negative relationship between temperature and GEP in July, but no relationship in August and September. Consideration of sub-annual climate conditions and the inclusion of the effect of temperature on the water balance allowed us to generalize the functional responses of vegetation to predicted future climate conditions. We conclude that across biomes, drought conditions during critical sub-annual climate periods could have a strong negative impact on vegetation production in the southwestern United States.

Ce travail s’inscrit dans le cadre d’un programme de recherches appuyé par le Conseil de recherches en sciences humaines du Canada. / Les forêts de Bornéo sont inestimables. En plus d’une faune et d’une flore riche et diversifiée, ses milieux naturels constituent d’efficaces réservoirs de carbone. En outre, la matière ligneuse qui y est abondante fait l’objet d’une exploitation intensive. Par contre, c’est le potentiel agricole de l’île qui crée le plus d’enthousiasme, principalement en ce qui concerne la culture du palmier à huile. Pour tenter de mieux comprendre et surveiller le phénomène, nous avons développé des méthodes de détection de la déforestation et de la dégradation des forêts. Ces méthodes doivent tenir compte des caractéristiques propres à l’île. C’est que Bornéo est abondamment affectée par une nébulosité constante qui complexifie considérablement son observation à partir des satellites. Malgré ces contraintes, nous avons produit une série chronologique annuelle des points chauds de déforestation et de dégradation des forêts pour les années 2000 à 2009. / Borneo’s forests are priceless. Beyond the richness and diversity of its fauna and flora, its natural habitats constitute efficient carbon reservoirs. Unfortunately, the vast forests of the island are rapidly being cut down, both by the forestry industry and the rapidly expanding oil palm industry. In this context, we’ve developed methods to detect deforestation and forest degradation in order to better understand and monitor the phenomena. In doing so, the peculiarities of Borneo, such as the persistent cloud cover, had to be accounted for. Nevertheless, we succeeded in producing a time series of the yearly forest degradation and deforestations hotspots for the year 2000 through the year 2009.

Les forêts de Bornéo sont inestimables. En plus d’une faune et d’une flore riche et diversifiée, ses milieux naturels constituent d’efficaces réservoirs de carbone. En outre, la matière ligneuse qui y est abondante fait l’objet d’une exploitation intensive. Par contre, c’est le potentiel agricole de l’île qui crée le plus d’enthousiasme, principalement en ce qui concerne la culture du palmier à huile. Pour tenter de mieux comprendre et surveiller le phénomène, nous avons développé des méthodes de détection de la déforestation et de la dégradation des forêts. Ces méthodes doivent tenir compte des caractéristiques propres à l’île. C’est que Bornéo est abondamment affectée par une nébulosité constante qui complexifie considérablement son observation à partir des satellites. Malgré ces contraintes, nous avons produit une série chronologique annuelle des points chauds de déforestation et de dégradation des forêts pour les années 2000 à 2009. / Borneo’s forests are priceless. Beyond the richness and diversity of its fauna and flora, its natural habitats constitute efficient carbon reservoirs. Unfortunately, the vast forests of the island are rapidly being cut down, both by the forestry industry and the rapidly expanding oil palm industry. In this context, we’ve developed methods to detect deforestation and forest degradation in order to better understand and monitor the phenomena. In doing so, the peculiarities of Borneo, such as the persistent cloud cover, had to be accounted for. Nevertheless, we succeeded in producing a time series of the yearly forest degradation and deforestations hotspots for the year 2000 through the year 2009. / Ce travail s’inscrit dans le cadre d’un programme de recherches appuyé par le Conseil de recherches en sciences humaines du Canada.

[ES] El Trastorno del Espectro Autista (TEA) es una afección compleja que se encuentra dentro de los llamados Trastornos del Neurodesarrollo. Está caracterizada por la presencia de disfunciones en las interacciones sociales, en la capacidad comunicativa, pensamiento simbólico, así como, conductas estereotipadas y desregulación de carácter sensorial. Actualmente, dada su elevada prevalencia, ha despertado el interés científico para poder llevar a cabo diagnósticos más tempranos que repercutan en intervenciones más eficaces. Hasta el momento el diagnóstico del TEA se ha venido realizando mediante baterías diagnósticas estandarizadas basadas en criterios cualitativos, por lo cual, la respuesta puede distar de la obtenida en un contexto real. Es por ello que herramientas como la Realidad Virtual (RV), con la potencialidad de reproducir entornos con elevado grado de realismo, pueden ser un contexto válido tanto para la evaluación como para la intervención terapéutica. Se han aplicado entornos virtuales no inmersivos, dado el rechazo de la población TEA a utilizar visores RV, aunque con resultados observacionales. Dichas limitaciones pueden superarse con el uso de los llamados Entornos Virtuales Inmersivos (EVI), ya que suponen una solución tecnológica no invasiva, con mayor capacidad de inmersión y, por tanto, de generar respuestas con mayor similitud a las obtenidas en un contexto real. Las mediciones de carácter observacional pueden superarse con mediciones fisiológicas, tales como, la actividad electrodermal (EDA), que proporciona la respuesta de la excitación corporal en forma de sudoración ante un estímulo o el eye tracking, el cual muestra el comportamiento ocular. Ambas suponen respuestas implícitas, inconscientes y cuantificables, que pueden ayudar a definir la afección. Por todo ello, la presente Tesis Doctoral, compuesta de tres estudios, tiene como objetivo unir el uso de EVI, con capacidad de estimulación visual, auditiva y olfativa con medidas fisiológicas, focalizadas en la evaluación y entrenamiento del TEA, además de estudiar las relaciones entre las mismas y las baterías diagnósticas del TEA. El Estudio nº 1 valoró la adaptación de los participantes a los dispositivos y el EVI y los niveles EDA en un contexto de respuesta al saludo. Los resultados hallaron que los sujetos TEA mostraron una tolerancia similar en el uso del EVI y del dispositivo EDA. Aumentaron sus niveles de excitación con respecto al estado de reposo previo (Ratio), cuando intervino el sentido del olfato, no habiendo relaciones significativas con las baterías diagnósticas. El Estudio nº 2 profundizó en los niveles EDA en un contexto de imitación total o parcial. Los resultados mostraros que los sujetos TEA mostraron una menor activación (Ratio), ante procesos de imitación total, con estimulación olfativa, no encontrando relaciones significativas con las baterías diagnósticas. El Estudio nº 3 estudió el EDA y el comportamiento ocular en un EVI basado en un Centro Comercial. Los resultados EDA, no proporcionaron diferencias en la sesión de evaluación, pero descendieron en los sujetos TEA tras una sesión de entrenamiento. El comportamiento ocular en la sesión de evaluación discriminó entre los grupos, pero en el entrenamiento el comportamiento fue similar. Las relaciones entre dichas medidas y las baterías diagnósticas no mostraron relaciones significativas. Tecnologías inmersivas y medidas psicofisiológicas para la evaluación y entrenamiento de niños con Trastorno del Espectro Autista Como conclusión final cabe señalar que, la medida electrodermal que contó con mayor capacidad para identificar a la población TEA fue la medida Ratio. Mientras que el EDA, tras el entrenamiento, fue indicador de una mejora de la excitación ante situaciones de señalado, respuesta al nombre y atención conjunta, en el caso del comportamiento ocular, fue capaz de diferenciar entre los grupos únicamente en la / [CA] El Trastorn de l'Espectre Autista (TEA) és una afecció complexa que es troba dins dels anomenats Trastorns del Neurodesenvolupament. Està caracteritzada per la presència de disfuncions en les interaccions socials, en la capacitat comunicativa, pensament simbòlic, així com, conductes estereotipades i desregulació del caràcter sensorial. Actualment, donada la seua elevada prevalença, ha despertat l'interés científic per poder dur a terme diagnòstics més primerencs que deriven en intervencions més eficaces. Fins al moment el diagnòstic del TEA s'ha realitzat mitjançant bateries diagnòstiques estandarditzades basades en criteris qualitatius, és per això que la resposta pot ser diferent a l'obtinguda en un context real. Per tant, eines com la Realitat Virtual, amb la capacitat de reproduir entorns amb un elevat grau de realisme, poden ser un context vàlid tant per a l'avaluació com per a la intervenció terapèutica. S'han aplicat entorns virtuals no immersius, donat el rebuig de la població TEA a utilitzar visors RV, malgrat que amb resultats observacionals. Dites limitacions poden superar-se amb l'ús dels anomenats Entorns Virtuals Immersius (EVI), ja que suposen una solució tecnològica no invasiva, amb major capacitat d'immersió i per tant, de generar respostes amb major similitud a les obtingudes en un context real. Les mesures de caràcter observacional poden superar-se amb mesures fisiològiques, tals com, l'activitat electrodermal (EDA), que proporciona la resposta de l'excitació corporal en forma de sudoració enfront d'un estímul o l'eye tracking, el qual mostra el comportament ocular. Ambdues suposen respostes implícites, inconscients i quantificables, que poden ajudar a definir l'afecció. Per tot això, la present Tesi Doctoral, composta de tres estudis, té com a objectiu unir l'ús d'EVI, amb capacitat d'estimulació visual, auditiva i olfactiva amb mesures fisiològiques, focalitzades en l'avaluació i entrenament del TEA, a més d'estudiar les relacions entre les mateixes i les bateries diagnòstiques del TEA. L'Estudi nº 1 va valorar l'adaptació dels participants als dispositius i l'EVI i els nivells EDA en un context de resposta salutació. Els resultats van trobar que els subjectes TEA van mostrar una tolerància similar en l'ús d'EVI i del dispositiu EDA. Van augmentar els seus nivells d'excitació pel que fa a l'estat de repòs prEVI (Ràtio), quan va intervenir el sentit de l'olfacte, no havent-hi relacions significatives amb les bateries diagnòstiques. L'Estudi nº 2 va aprofundir en els nivells EDA en un context d'imitació total o parcial. Els resultats mostraren que els subjectes TEA mostraren una menor activació (Ràtio), davant de processos d'imitació total, amb estimulació olfactiva, no trobant relacions significatives amb les bateries diagnòstiques. L'Estudi nº 3 va estudiar l'EDA i el comportament ocular a un EVI basat en un Centre Comercial. Els resultats EDA, no van proporcionar diferències en la sessió d'avaluació, però van baixar en els subjectes TEA després d'una sessió d'entrenament. El comportament ocular en la sessió d'avaluació va discriminar entre els grups, però en l'entrenament el comportament va ser similar. Les relacions entre aquestes mesures i les bateries diagnòstiques no van mostrar relacions significatives. Com a conclusió final es pot assenyalar que, la mesura electrodermal que va comptar amb major capacitat per a identificar a la població TEA fou la mesura Ràtio. Pel quefa a l'EDA, després de l'entrenament, va ser un indicador d'una millora de l'excitació enfront de situacions d'assenyalament, resposta al nom i atenció conjunta, en el cas del comportament ocular, va ser capaç de diferenciar entre els grups únicament en la sessió d'avaluació. Finalment, l'EDA i el comportament ocular, no van ser mesures amb capacitat correlacional amb les bateries diagnòstiques. / [EN] Autism Spectrum Disorder (ASD) is a complex condition that falls under the category of so-called Neurodevelopmental Disorders. It is characterized by the presence of dysfunctions in social interactions, in the communicative capacity, symbolic thinking, as well as, stereotypical behaviours and deregulation of sensorial character. Currently, given its high prevalence, it has awakened scientific interest in order to carry out earlier diagnoses that will have an impact on more effective interventions. Until now, the diagnosis of ASD has been carried out by means of standardized diagnostic batteries based on qualitative criteria, so that the response may be far from that obtained in a real context. Therefore, tools such as Virtual Reality (VR), with the potential to reproduce highly realistic environments, can be a valid context for both assessment and therapeutic intervention. Non-immersive virtual environments have been applied, given the refusal of the ASD population to use VR viewers, although with bservational results. These limitations can be overcome with the use of so-called Immersive Virtual Environments (IVEs), since they represent a non-invasive technological solution, with a greater capacity for immersion and, therefore, for generating responses that are more similar to those obtained in a real context. Observational measurements can be overcome with physiological measurements, such as electrodermal activity (EDA), which provides the body's response in the form of sweating to a stimulus, or eye tracking, which shows the behaviour of the eye. Both involve implicit, unconscious and quantifiable responses, which can help define the condition. Consequently, the present Doctoral Thesis, composed of three studies, aims to unite the use of IVE, with the capacity of visual, auditory and olfactory stimulation with physiological measures, focused on the evaluation and training of ASD, as well as studying the relationships between them and the diagnostic batteries of ASD. The Study nº1 evaluated the adaptation of the participants to the deviIces and the IVE and the EDA levels in a context of response to the greeting. The results found that ASD subjects showed similar tolerance in the use of the IVE and EDA dEVIce. They increased their levels of arousal with respect to the prEVIous resting state (Ratio), when the sense of smell was involved, with no significant relationship with the diagnostic batteries. Study nº2 studied in depth the EDA levels in a context of total or partial imitation. The results show that the ASD subjects showed a lower activation (Ratio), when facing total imitation processes, with olfactory stimulation, finding no significant relations with the diagnostic batteries. The Study nº3 studied the EDA and the ocular behaviour in an IVE based in a Shopping Centre. The EDA results, did not provide differences in the evaluation session, but they decreased in the ASD subjects after a training session. Eye behaviour in the assessment session discriminated between the groups, but in the training the behaviour was similar. The relationships between these measures and the diagnostic batteries did not show significant relationships. As a final conclusion, it should be pointed out that the electrodermal measure that had more capacity to identify the ASD population was the Ratio measure. While the EDA, after the training, was an indicator of an improvement of the excitement in front of situations of signalling, response to the name and joint attention, in the case of the ocular behaviour, it was one able to differentiate between the groups only in the evaluation session. Finally, the EDA and the ocular behaviour, were not measured with correlational capacity with the diagnostic batteries. / Olmos Raya, E. (2021). Tecnologías Inmersivas y medidas psicofisiológicas para la evaluación y entrenamiento de niños con Trastorno del Espectro Autista [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165871 / TESIS