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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Using remote sensing to monitor herbicide injury and biomass of waterhyacinth

Robles, Wilfredo 08 August 2009 (has links)
Aquatic vegetation plays an important role in the ecological interactions and processes within a water body. However, the presence of the invasive exotic aquatic plant species, waterhyacinth [Eichhornia crassipes (Mart.) Solms], negatively affects those interactions as well as interfering with water use for recreation and navigation. An implemented management plan for waterhyacinth control relies on the use of herbicides. Efficacy is commonly assessed using visual injury and control ratings as well as estimating biomass. The problem is that those approaches are labor intensive only assessing single points throughout the entire water body. Therefore, technology like remote sensing, which is the focus of this research, is recommended as an additional tool to assess implemented management plans. Studies were conducted in a mesocosm research facility to evaluate the relationship between simulated spectral bands 3, 4, 5, and 7 Landsat 5 TM and waterhyacinth treated with the herbicides imazapyr and glyphosate. Results indicate that injury is better detected and predicted with band 4 and that relationship is negative when either herbicide was used. However, prediction is better when plants have developed sufficient injury to influence the spectral response of band 4. In the second study, the biomass of waterhyacinth was estimated using the Normalized Difference Vegetation Index (NDVI) using simulated data from Landsat 5 TM. This study was conducted over natural populations of waterhyacinth in Lakes Columbus and Aberdeen, MS over two growing seasons. Results indicate that the use of NDVI alone is a weak predictor of biomass; however, its combination with morphometric parameters like leaf area index enhanced predictive capabilities.In order to assess field herbicide treatments for waterhyacinth control and its consequent impact on native aquatic vegetation, lake-wide surveys were performed in Lake Columbus, MS using a point-intercept method. The herbicide assessed was 2,4-D which was applied aerially and by boats. Point-intercept surveys in a 400 by 400 grid of points aided with global positioning system (GPS) were performed before and after herbicide treatments. Obtained results indicate that the frequency of occurrence of waterhyacinth significantly decreased after herbicide treatments which consequently led to the reestablishment of native aquatic vegetation on the system.
2

DENSIDADE URBANA E POPULACIONAL E SEUS EFEITOS MULTITEMPORAIS NA CIDADE DE CASCAVEL/PR / URBAN AND POPULATIONAL DENSITY AND ITS MULTITEMPORAL EFFECTS IN CASCAVEL-PR

Valmorbida, Leomar 28 March 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work compares the urban growth, between the years of 1995 and 2006, with the population evolution of the demographic censuses, carried through between the years of 2000 and 2010. The delimitation and classification of the urban density, in categories, occurred from interpretation of the satellite images of the Landsat-5 sensor Thematic Mapper . Bands 3, 4 and 5 were used, in false composition color (R5G4B3). The classifications of urban density were defined as: high, average and low density. The demographic data concerning the censuses were extracted from the IBGE census sectors. Both the data from satellite images and census data were indexed in a georreferenced base. The grouping of census sectors leads to the use of samples pertinent to the complaints of taxpayers regarding the urban tax registration, registered and ceded by the Municipality of Cascavel/PR. It was also verified the expansion of urban density ratings in conjunction with population growth and percentage of urban area. It was found that, the greatest population evolution was observed in the class of low urban density. While the middle class urban density got minor population growth and urban expansion. It was also observed that the complaints were present in all urban density classes. Thus, we could relate the percentage of dissatisfactions contained in the classification of low urban density as areas of greater flexibility and expansion activities. This framework has made the data became more easily outdated. The changes in terms of constructions, land divisions, zoning and growth occur with intensity in the peripheries, just by the availability of spaces to be explored. The claims generated by users/contributors distributed by region and specialized in the urban area of Cascavel/PR point to the values attributed to the IPTU, taxes, as garbage collection and public lighting and, mainly, regarding the divergences in the measures of the properties (building, houses), that in some cases are with greater measure in the urban tax registration in relation to the constructed area and this affects the value to be collected for IPTU and taxes. / Este trabalho compara o crescimento urbano, entre os anos de 1995 e 2006, com a evolução populacional dos censos demográficos, realizados entre os anos de 2000 e 2010. A delimitação e classificação da densidade urbana, em categorias, ocorreram a partir de interpretação das imagens do satélite Landsat-5 sensor Thematic Mapper . Foram utilizadas as bandas 3, 4 e 5, em composição falsa-cor (R5G4B3). As classificações de densidade urbana foram assim definidas: alta, média e baixa densidade. Os dados demográficos referentes aos censos foram extraídos dos setores censitários do IBGE. Tanto os dados das imagens de satélite quanto os dados censitários foram indexados em base georreferenciada. O agrupamento dos setores censitários remete a utilização de amostras pertinente às reclamações dos contribuintes referente ao cadastro tributário urbano, registrado e cedido pela Prefeitura Municipal de Cascavel/PR. Foi, ainda, verificada a expansão das classificações de densidade urbana em conjunto com o crescimento populacional e percentual da área urbana. Constatou-se que, a maior evolução populacional foi observada na classe baixa densidade urbana. Enquanto a classe média densidade urbana obteve menor crescimento populacional e expansão urbana. Observou-se, ainda, que as reclamações estiveram presentes em todas as classes de densidade urbana. Dessa forma, pôde-se relacionar o percentual das insatisfações contidas na classificação de baixa densidade urbana como áreas de maior flexibilidade e ações de expansão. Este quadro fez com que os dados se tornassem mais facilmente desatualizados. As mudanças em termos de edificações, loteamentos, zoneamento e crescimento ocorrem com intensidade nas periferias, justamente pela disponibilidade de espaços a serem explorados. As reclamações geradas pelos usuários/contribuintes distribuídos por região e espacializada na área urbana de Cascavel/PR apontam para os valores atribuídos ao IPTU, taxas como coleta de lixo e iluminação pública e, principalmente, quanto às divergências nas medidas dos imóveis (prédios, casas), que em alguns casos se encontram com metragem maior no cadastro tributário urbano em relação ao construído e isto afeta o valor a ser recolhido de IPTU e taxas.
3

Estimativa do balanço de radiação com técnicas de sensoriamento remoto e dados de superfície / Estimation the balance of radiation using techniques of remote sensing and surface data

GIONGO, Pedro Rogério 29 January 2008 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-18T12:35:22Z No. of bitstreams: 1 Pedro Rogerio Giongo.pdf: 8561416 bytes, checksum: 9518df2b8c5f4fdab4d53cd51d03d547 (MD5) / Made available in DSpace on 2016-10-18T12:35:22Z (GMT). No. of bitstreams: 1 Pedro Rogerio Giongo.pdf: 8561416 bytes, checksum: 9518df2b8c5f4fdab4d53cd51d03d547 (MD5) Previous issue date: 2008-01-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The remote sensing is a tool that has enabled major advances in studies of agrometeorology and application to areas with different types of coverage, can be used to estimate the radiation balance and its applications. Therefore this study aimed to estimate the balance of radiation to the surface, from the sensor data Thematic Mapper (TM) satellite LANDSAT 5, with the use of the algorithm SEBAL. The estimate data were compared with data from two stations in agrometeorological: one in the cerrado region, and another in sugar cane. In the study area, located in the municipality of Santa Rita do Passa Quatro - SP, Brazil. To carry out the study were obtained six orbital images from the satellite Landsat 5 TM sensors in orbit 220 in section 75, the dates of 22/02, 11/04, 29/05, 01/08, 17/08 and 21/11 all in the year 2005, the matching DJ of 53, 101, 149, 213, 229 and 325, respectively. We performed the geometric correction for images, then were generated the letters of albedo, the Normalised Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), leaf area Index (LAI), surface temperature (Ts), Long Wave Radiation of Issued and Balance of Radiation (Rn). The estimated values of Rn showed correlations r of 0,994 and 0,984 with data from the stations inthe area sugar cane and cerrado, respectively. It concludes that the proposed methodology of the algorithm SEBAL for estimation of Rn for the two areas, values achieved very consistent and satisfactory for this application. / O sensoriamento remoto é uma ferramenta que tem possibilitado grandes avanços a estudos da agrometeorologia, bem como aplicação a superfícies com diferentes tipos de cobertura, podendo ser utilizado para estimativas do saldo de radiação e suas aplicações. Assim este trabalho objetivou estimar o Balanço de Radiação à Superfície, a partir de dados do sensor Thematic Mapper (TM) do satélite LANDSAT 5, com a utilização do algoritmo SEBAL. Os dados estimados foram comparados com dados de duas estações agrometeorológicas em superfície: uma em região de Cerrado, e outra em Cana-de-Açúcar. A região de estudo fica localizada no município de Santa Rita do Passa Quatro – SP, Brasil. Para a realização do estudo foram obtidas seis imagens orbitais do satélite Landsat 5 sensores TM, na órbita 220 e ponto 75, nas datas de 22/02, 11/04, 29/05, 01/08, 17/08 e 21/11 todas do ano de 2005, a que correspondem aos DJ de 53, 101, 149, 213, 229 e 325, respectivamente. Foram realizadas as correções geométricas para as imagens, em seguida foram geradas as cartas de albedo, Índice de Vegetação da Diferença Normalizada (NDVI), Índice de Vegetação Ajustado ao Solo (SAVI), Índice de Área Foliar (IAF), Temperatura de superfície (Ts), Radiação de OndaLonga Emitida e Saldo de Radiação (Rn). Os valores do Rn estimados apresentaram correlações de r iguais a 0,994 e 0,984 com os dados de superfície das estações da Cana-de-açúcar e Cerrado, respectivamente. Conclui-se que a metodologia proposta do algoritmo SEBAL, para estimativa de Rn para as duas áreas, alcançou valores muito consistentes e satisfatórios para essa aplicação.
4

Cartografia temporal e an?lise geoambiental da din?mica da foz do Rio Piranhas-A?u, regiao de Macau-RN, com base em imagens Landast 5-MT

Alves, Adriano de Lima 25 April 2001 (has links)
Made available in DSpace on 2015-03-13T17:08:22Z (GMT). No. of bitstreams: 1 AdrianoLAM_Introducao_ate_Cap3.pdf: 1542020 bytes, checksum: acc2a954ad78e8e953630472a4fb07e5 (MD5) Previous issue date: 2001-04-25 / This work embraces the application of Landsat 5-TM digital images, comprising August 2 1989 and September 22 1998, for temporal mapping and geoenvironmental analysis of the dynamic of Piranhas-A?u river mouth, situated in the Macau (RN) region. After treatment using several digital processing techniques (e.g. colour composition in RGB, ratio of bands, principal component analysis, index methods, among others), it was possible to generate several image products and multitemporal maps of the coastal morphodynamics of the studied area. Using the image products it was possible the identification and characterization of the principal elements of interest (vegetation, soil, geology and water) in the surface of the studied area, associating the spectral characteristics of these elements to that presented by the image products resulting of the digital processing. Thus, it was possible to define different types of soils: Amd, AQd6, SK1 and LVe4; vegetation grouping: open arboreal-shrubby caatinga, closed arborealshrubby caatinga, closed arboreal caatinga, mangrove vegetation, dune vegetation and areas predominately constituted by juremas; geological units: quaternary units beach sediments, sand banks, dune flats, barrier island, mobile dunes, fixed dunes, alluvium, tidal and inundation flats, and sandy facies of the Potengi Formation; tertiary-quaternary units Barreiras Formation grouped to the clayey facies of the Potengi Formation, Macau Formation grouped to the sediments of the Tibau Formation; Cretaceous units Janda?ra Formation; moreover it was to identify the sea/land limit, shallow submersed areas and suspended sediments. The multitemporal maps of the coastal morphodynamics allowed the identification and a semi-quantitative evoluation of regions which were submitted to erosive and constructive processes in the last decade. This semi-quantitative evoluation in association with an geoenvironmental characterization of the studied area are important data to the elaboration of actions that may minimize the possible/probable impacts caused by the implantation of the Polo Gas/Sal and to the monitoring of areas explorated by the petroleum and salt industries / Este trabalho trata da aplica??o dos dados das imagens digitais do Landsat 5-TM, dos per?odos de 02/08/1989 e 22/09/1998, na cartografia temporal e an?lise geoambiental da din?mica da Foz do Rio Piranhas-A?u, na regi?o de Macau-RN. Essas imagens, ap?s serem submetidas a diversas t?cnicas de processamento digital (composi??o colorida em RGB, raz?o entre bandas, an?lise por principais componentes, m?todos de ?ndices, entre outros) proporcionaram a gera??o de diversos produtos imagem e de mapas multitemporais da morfodin?mica costeira da ?rea de estudo. Por meio dos produtos imagem foi poss?vel realizar a identifica??o e caracteriza??o dos principais elementos de interesse contidos na superf?cie da ?rea estudada (vegeta??o, solo, geologia e ?gua), associando as caracter?sticas espectrais destes ?quelas apresentadas nos produtos imagem resultantes dos processamentos digitais. Desta forma foi poss?vel definir os diferentes tipos de solos: Amd, AQd6, SK1 e LVe4; agrupamentos de vegeta??o: caatinga arbustiva-arb?rea aberta, caatinga arbustiva-arb?rea fechada, caatinga arb?rea fechada, vegeta??o de mangue, vegeta??o de dunas e ?reas constitu?das prodominantemente por juremas; unidades geol?gicas: unidades quatern?rias sedimentos quartzo-arenosos de praias, restingas, pisos de dunas, ilha barreira, dunas m?veis, dunas fixas, aluvi?es, plan?cies de mar? e de inunda??o, f?cies arenosa da Forma??o Potengi - ; unidades t?rcioquatern?rias Forma??o Barreiras agrupada ?s f?cies argilosas dos sedimentos terci?rios da Forma??o Potengi, sedimentos da Forma??o Tibau agrupados aos basaltos e diab?sios terci?rios da Forma??o Macau - ; unidade cret?cea Forma??o Janda?ra; al?m de identificar o limite terra/mar, ?reas submersas rasas e sedimentos em suspens?o. Os mapas multitemporais da morfodin?mica costeira permitiram a identifica??o e uma avalia??o semi-quantitativa das regi?es que foram submetidas a processos erosivos e construtivos nessa ?ltima d?cada. Essa avalia??o semi-quantitativa associada a caracteriza??o geoambiental da ?rea estudada, representam, desta forma, importantes dados para elabora??o de medidas que possam minimizar os poss?veis/prov?veis impactos a serem causados com a implanta??o do P?lo G?s-Sal e para o monitoramento das ?reas de explora??o das ind?strias do petr?leo e do sal
5

Dinamica espectral da cultura da soja ao longo do ciclo vegetativo e sua relação com a produtividade na região oeste do Parana / Spectral dynamic of the soybean crop along the vegetative cycle and its relation with the yield in the western region of Parana state

Mercante, Erivelto 17 August 2007 (has links)
Orientador: Rubens Augusto Camargo Lamparelli / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-09T05:37:08Z (GMT). No. of bitstreams: 1 Mercante_Erivelto_D.pdf: 2989061 bytes, checksum: 75872d2f0b562b1a4ee7798a720abb60 (MD5) Previous issue date: 2007 / Resumo: Estudos e pesquisas referentes ao acompanhamento da produção agropecuária têm um peso determinante e estratégico na economia do país. Nos últimos anos, essas pesquisas vêm sofrendo grandes transformações para se tornarem menos subjetivas. A associação das técnicas de sensoriamento remoto e métodos estatísticos podem proporcionar uma visão sinóptica das áreas semeadas, gerando, assim informações sobre a área plantada das culturas e a variabilidade existente nelas. Entretanto, a utilização dos dados provenientes de imagens de satélites está condicionada, principalmente, às propriedades de refletância e absorção dos componentes da superfície e pelo comportamento da atmosfera. Dentre as culturas de grande valor econômico, a soja (Glycine max (L) Merrill.) se destaca como um dos principais produtos da agricultura brasileira, assumindo grande importância econômica nas exportações. O estado do Paraná se destaca como um dos maiores produtores agrícolas do país, e a sua economia é baseada principalmente na agricultura voltada para a produção de grãos. Neste contexto, o objetivo da pesquisa foi estudar a relação entre o comportamento espectral da cultura de soja com a ao longo de seu ciclo de desenvolvimento, gerando informações e metodologias para auxiliar no acompanhamento da produção e estimativa de área da cultura na região Oeste do Paraná. As áreas monitoradas abrangem 36 municípios e duas áreas agrícolas comerciais localizadas próximas ao município de Cascavel/PR. Foram utilizadas imagens do satélite Landsat 5/TM (cena órbita/ponto 223/77) e imagens do satélite Terra sensor MODIS (produto MOD13Q1), caracterizando, assim, a passagem de escala entre as imagens dos dois sensores com resoluções espaciais diferentes. Dados de produtividade da cultura foram coletados nas escalas local (para as duas áreas monitoradas) e regional junto à Secretária de Agricultura e Abastecimento do Paraná ¿ SEAB (para os 36 municípios). A cultura da soja foi monitorada nas safras 2003/2004 e 2004/2005 utilizando imagens dos satélites. Para a utilização das imagens do satélite Landsat 5/TM de forma multitemporal foram realizados ainda os procedimentos de correção atmosférica e normalização de imagens. No intuito de caracterizar a resposta espectral da biomassa da cultura da soja e a sua relação com a produtividade final, geraram-se imagens referentes aos índices de vegetação NDVI e GVI. Foram realizadas análises de correlação e regressão entre dados de produtividade (variável predita) e dados espectrais (variável preditora) oriundos dos índices de vegetação (NDVI e GVI) em nível municipal (36 municípios) e local (duas áreas). Os resultados obtidos com a correção atmosférica e a normalização de imagens são coerentes quanto ao comportamento espectral dos alvos, vegetação e solo. Após o mapeamento das áreas com a cultura da soja (¿máscaras de soja¿), por meio das imagens temporais do Landsat 5/TM, foi possível realizar a passagem de escala para o sensor MODIS. O comportamento espectral da cultura se mostrou diferente para as imagens Landsat 5/TM com os tratamentos de refletância aparente, de superfície e de normalização. Por meio dos gráficos dos perfis espectrais traduzidos pelos índices NDVI e GVI foi possível acompanhar o ciclo de desenvolvimento da cultura da soja. As melhores correlações e regressões lineares entre os parâmetros espectrais e a produtividade final ocorreram quando considerado todo o ciclo de desenvolvimento da cultura. Quanto aos índices de vegetação utilizados NDVI e GVI, observou-se que o GVI teve comportamento com menor variação quando analisado os resultados das regressões. Em síntese, os resultados demonstraram que utilizando somente técnicas de modelagem estatística com dados espectrais foi possível estimar em até 85% a variabilidade encontrada na produtividade da soja / Abstract: Studies and researches referring to attendance of the agropecuary production have a determinant strategic importance in the economy of the country. In the last years, those researches have been suffering great transformations to become less subjectives. The association of the remote sensing technique and statistic methods can provide a synoptic view of the seeded areas, in this manner producing information about the planted area of the crops and the variability on them. However, the use of data from the images of satellite is stipulated mainly to the reflectivity properties and absorption of the surface components and also for the atmosphere behaviour. Amongst the crops of great economic value, the soybean (Glycine max (L) Merrill.) emphasizes as one of the main product of the Brazilian agriculture, assuming big economic importance in the exportations. The Paraná state stands out as one of the biggest agricultural producers of the country, and its economy is based mainly towards to the production of grains. In this context, the aim of the research was study the relation between the spectral behaviour of the soybean crop with the end yield along its development cycle, producing information and methodologies to assist the attendance of the production and area estimation of the western Paraná region crop. The areas monitored reach 36 municipal districts and two agricultural commercial areas located near of Cascavel/PR. It was used images from satellite Landsat 5/TM (orbit/point 223/77) and images of the satellite Terra sensor MODIS (product MOD13Q1), then characterizing the crossing scale between the images from both sensors with different spatial resolution. Crop yield data were collected, in the local scale (to both monitored areas) and in the regional scale together with the Secretary of Agriculture (SEAB) (to the 36 municipal districts). Through the satellites images, the soybean crop was monitored in the 2003/2004 and 2004/2005 harvests. For the use of images from the satellite Landsat 5/TM of multitemporal form was realized the proceeding of atmospheric correction and image normalization. In the aim of distinguishing the biomass spectral answer of the soybean crop and its relation to the end yield, it was created images referring to vegetation indexes NDVI and GVI. It was accomplished analyses of correlation and regression between the yield data (variable predict) and spectral data (variable predictor) derived from vegetation indexes (NDVI and GVI) in municipal level (36 municipal districts) and local (two areas). The results obtained with the atmospheric correction and image normalization presented coherent as to the spectral behaviour of the vegetation and soil target. After the area mapping with the soybean crop (soybean mask) by the temporary images of Landsat 5/TM, it was possible to realize the cross-scale to the MODIS sensor. The spectral behaviour of the crop was showed different in the Landsat 5/TM images to the apparent reflectance usage, surface and normalization. By mean of the graphics of spectral profile translated from the NDVI and GVI indexes was possible follow the development cycle of the soybean crop. The best correlations and linear regressions between the spectral parameters and the end yield will occur when it is considered all the cycle of the crop development. For the matters of vegetation indexes NDVI and GVI used, it was observed that the GVI had a less variable behaviour when analysed the results of regressions. In the sum up, the results showed that using only statistical modelling techniques with spectral data was possible estimate 85% of variability found in the soybean yield / Doutorado / Planejamento e Desenvolvimento Rural Sustentável / Doutor em Engenharia Agrícola
6

ESTIMATION OF EVAPOTRANSPIRATION OF COTTONWOOD TREES IN THE CIBOLA NATIONAL WILDLIFE REFUGE, CIBOLA, ARIZONA

JETTON, AMITY J. 29 May 2008 (has links)
No description available.
7

Landscape dynamics from 1990--2010 and the human to apex predator (red-tailed hawk) relationship on La Gonave, Haiti

White, Justin Haehlen 21 January 2013 (has links)
The island of La Gonave, ~50 km northwest of Port-au-Prince, represents the subsistence Haitian lifestyle. Little is known about human--environment interactions on La Gonave. The first objective of this research was to investigate landscape dynamics through image classification, change detection, and landscape pattern analysis using Landsat 5 (TM) imagery from 1990--2010. Five land cover classes were considered: Agriculture, Forest/Dense Vegetation (DV), Shrub, Barren/Eroded, and Nonforested Wetlands. Overall image classification accuracy was 87%. The area percent change was -39.7, -22.7, 87.4, -7.0, 10.2%, for the respective classes. Landscape pattern analysis illustrated the encroachment of Shrub in core Forest/DV patches and the decline of Agricultural patch integrity. Agricultural abandonment, deforestation, and forest regrowth generated an increasingly fragmented landscape. The second objective of this research was to better understand the survival of the red-tailed hawk (RTH) on La Gonave by exploring the human--RTH relationship. We implemented a survey (n = 121) in 10 rural villages on La Gonave regarding their perceptions and interactions with the RTH during May--June, 2012. During fieldwork we sighted seven RTHs and found one nest. Many respondents noted the aggressive behavior of RTHs during nesting, suggesting reproductive behavior on the island. Our results indicate that RTHs inhabiting this island were not persecuted, despite intense predation of domestic chickens. Aside from predation near homes, villagers do not interact with the hawk as it remains out of sight. The RTH currently has no known predators, but it remains in danger of island extirpation due to ecological degradation. / Master of Science
8

Monitorización de cambios en la lámina libre de agua en humedales mediante teledetección

Pena Regueiro, Jesús 07 September 2023 (has links)
Tesis por compendio / [ES] Los humedales son uno de los ecosistemas que reciben mayor atención por parte de la comunidad científica. Su importancia se puede explicar teniendo en cuenta que ayudan a mitigar los efectos de inundaciones, pueden actuar como filtros de agua y constituyen hábitats de valiosas especies de fauna y flora. En los últimos años este tipo de ambientes están cada vez más amenazados como consecuencia de la contaminación, alteraciones de los niveles de agua asociadas a los efectos del cambio climático y usos antrópicos, introducción de especies invasoras y los efectos negativos de algunos cambios de usos del suelo y determinadas prácticas asociados a ellos (agrícolas, pastoreo y urbanización). Para analizar estos ecosistemas, la teledetección se presenta como una herramienta con alto potencial que permite identificar, evaluar y monitorizar estos espacios. En esta tesis se utilizaron imágenes Sentinel-2A/B, Landsat-5 TM y Landsat-8 OLI para extraer láminas de agua libre en dos entornos: humedales mediterráneos costeros (Prat Cabanes-Torreblanca, Marjal de Sagunto, Marjal de La Safor y Marjal Pego-Oliva) y el humedal de llanura aluvial situado en el centro de España las Tablas de Daimiel. Para ello, se realizó un análisis de siete índices de agua (NDWI, mNDWI, Cedex, Re-NDWI, Awei(sh), AWEI (nsh) y B_Blue) y de umbrales para obtener la cartografía de las masas de agua libre en estos espacios. El objetivo principal es definir el índice y el umbral que permitan un uso más amplio de la metodología para su aplicación en otras zonas húmedas. También se utilizó información LiDAR (Laser Imaging Detection and Ranging) en el humedal de La Safor para analizar los efectos de la superficie inundada en diferentes usos del suelo. La evaluación de los resultados se realizó a partir de la validación con un conjunto de muestras obtenidas a partir de imágenes de elevada resolución espacial. Se calcularon la fiabilidad global y el índice kappa en los humedales analizados para distintas fechas y sensores. En el caso de los humedales costeros, el índice de agua NDWI con un umbral de ¿0,30 proporcionó los resultados con mayor precisión obteniendo un valor promedio de 0,89 en fiabilidad global. En el caso del humedal de las Tablas de Daimiel, se seleccionaron el índice MNDWI y umbral ¿0,15 para imágenes Landsat-5 (fiabilidad global 0,88), el índice MNDWI y umbral ¿0,25 para imágenes Landsat-8 (fiabilidad global 0,99) y el índice NDWI y umbral ¿0,20 (fiabilidad global 0,99) en el caso de imágenes Sentinel-2A/B. En el humedal de las Tablas de Daimiel se realizó un análisis temporal desde el año 2000 al 2021 que permitió calcular las anomalías de la superficie de agua, de la precipitación, del nivel piezométrico y del caudal hidrológico. Esta reconstrucción temporal también permitió comparar los resultados derivados a partir de las imágenes Sentinel-2A/B y de las imágenes Landsat 8. Se realizó un análisis de correlación entre los índices de anomalías calculados, que revela una correlación no significativa entre las anomalías precipitación y de superficie de agua. Mientras que el índice de anomalías de superficie de agua si presentó una correlación estadísticamente significativa con los índices de anomalía de caudal y de niveles piezométricos. En cuanto al análisis comparativo entre las imágenes Landsat-8 y Sentinel-2 se obtuvo una relación lineal entre la superficie de agua estimada por ambos sensores con un valor de R2 = 0,87. No obstante, la mayor resolución espacial de Sentinel-2 permite detectar masas de agua más pequeñas contribuyendo a un mejor análisis de los patrones de variabilidad en el área de estudio. La información derivada de esta tesis presenta una aplicabilidad de interés medioambiental para el seguimiento del estado de los humedales ayudando a adaptar planes de gestión que conduzcan a un estado de conservación adecuado. / [CA] Els aiguamolls són un dels ecosistemes que reben major atenció per part de la comunitat científica. La seua importància es pot explicar tenint en compte que ajuden a mitigar els efectes d'inundacions, poden actuar com a filtres d'aigua i constitueixen hàbitats de valuoses espècies de fauna i flora. En els últims anys aquest tipus d'ambients estan cada vegada més amenaçats a conseqüència de la contaminació, alteracions dels nivells d'aigua associades a l'efecte del canvi climàtic i usos antròpics, introducció d'espècies invasores i els efectes negatius d'alguns canvis d'usos del sòl i determinades pràctiques associades a ells (agrícoles, pasturatge i urbanització). Per a analitzar aquests ecosistemes, la teledetecció es presenta com una eina amb alt potencial que permet identificar, avaluar i monitorar aquests espais. En aquesta tesi es van utilitzar imatges Sentinel-2A/B, Landsat-5 TM i Landsat-8 OLI per a extraure làmines d'aigua lliure en dos entorns: aiguamolls mediterranis costaners (Prat Cabanes-Torreblanca, Marjal de Sagunt, Marjal de La Safor i Marjal Pego-Oliva) i l'aiguamoll de plana al·luvial situat en el centre d'Espanya les Taules de Daimiel. Per a això, es va realitzar una anàlisi de set índexs d'aigua (NDWI, mNDWI, Cedex, Re-NDWI, Awei (sh), AWEI (nsh) i B_Blue) i de llindars per a obtindre la cartografia de les masses d'aigua lliure en aquests espais. L'objectiu principal és definir l'índex i el llindar que permeten un ús més ampli de la metodologia per a la seua aplicació en altres zones humides. També es va utilitzar informació LiDAR (Laser Imaging Detection and Ranging) en l'aiguamoll de La Safor per a analitzar els efectes de la superfície inundada en diferents usos del sòl. L'avaluació dels resultats es va realitzar a partir de la validació amb un conjunt de mostres obtingudes a partir d'imatges d'elevada resolució espacial. Es van calcular la fiabilitat global i l'índex kappa en els aiguamolls analitzats per a diferents dates i sensors. En el cas dels aiguamolls costaners, l'índex d'aigua NDWI amb un llindar de ¿0,30 va proporcionar els resultats amb major precisió obtenint un valor mitjà de 0,89 en fiabilitat global. En el cas de l'aiguamoll de les Taules de Daimiel, es van seleccionar l'índex MNDWI i llindar ¿0,15 per a imatges Landsat-5 (fiabilitat global 0,88), l'índex MNDWI i llindar ¿0,25 per a imatges Landsat-8 (fiabilitat global 0,99) i l'índex NDWI i llindar ¿0,20 (fiabilitat global 0,99) en el cas d'imatges Sentinel-2A/B. En l'aiguamoll de les Taules de Daimiel es va realitzar una anàlisi temporal des de l'any 2000 al 2021 que va permetre calcular les anomalies de la superfície d'aigua, de la precipitació, del nivell piezomètric i del cabal hidrològic. Aquesta reconstrucció temporal també va permetre comparar els resultats derivats a partir de les imatges Sentinel-2A/B i de les imatges Landsat 8. Es va realitzar una anàlisi de correlació entre els índexs d'anomalies calculats, que revela una correlació no significativa entre les anomalies precipitació i de superfície d'aigua. Mentre que l'índex d'anomalies de superfície d'aigua si va presentar una correlació estadísticament significativa amb els índexs d'anomalia de cabal i de nivells piezomètrics. Quant a l'anàlisi comparativa entre les imatges Landsat-8 i Sentinel-2 es va obtindre una relació lineal entre la superfície d'aigua estimada per tots dos sensors amb un valor de R2 = 0,87. No obstant això, la major resolució espacial de Sentinel-2 permet detectar masses d'aigua de menor grandària contribuint a una millor anàlisi dels patrons de variabilitat en l'àrea d'estudi. La informació derivada d'aquesta tesi presenta una aplicabilitat d'interés mediambiental per al seguiment de l'estat dels aiguamolls ajudant a adaptar plans de gestió que condueixen a un estat de conservació adequat. / [EN] Wetlands are one of the ecosystems that receive the most attention from the scientific community. Their importance can be explained by the fact that they help mitigate the effects of flooding, can act as water filters, and provide habitats for valuable species of fauna and flora. In recent years, these types of environments are increasingly threatened as a result of pollution, alterations in water levels associated with the effects of climate change and anthropic uses, the introduction of invasive species and the negative effects of some changes in land use and certain practices associated with them (agriculture, grazing and urbanization). To analyze these ecosystems, remote sensing is presented as a tool with high potential to identify, evaluate and monitor these areas. In this thesis, Sentinel-2A/B, Landsat-5 TM and Landsat-8 OLI images were used to extract free water bodies in two environments: coastal Mediterranean wetlands (Prat Cabanes-Torreblanca, Marjal de Sagunto, Marjal de La Safor and Marjal Pego-Oliva) and the alluvial plain wetland located in the center of Spain, the Tablas de Daimiel. For this purpose, an analysis of seven water indices (NDWI, mNDWI, Cedex, Re-NDWI, Awei (sh), AWEI (nsh) and B_Blue) and thresholds were carried out to obtain the mapping of free water bodies in these areas. The main objective is to define the index and threshold that allow a wider use of the methodology for its application in other wetlands. LiDAR (Laser Imaging Detection and Ranging) information was also used in La Safor wetland to analyze the effects of the flooded surface on different land uses. The evaluation of the results was carried out based on the validation with a set of samples obtained from high spatial resolution images. The overall accuracy and the kappa index were calculated for the wetlands analyzed for different dates and sensors. In the case of the coastal wetlands, the NDWI water index with a threshold of ¿0.30 provided the most accurate results with an average value of 0.89 in global accuracy. In the case of Las Tablas de Daimiel wetland, the MNDWI index and threshold ¿0.15 were selected for Landsat-5 images (overall accuracy 0.88), the MNDWI index and threshold ¿0.25 for Landsat-8 images (overall accuracy 0.99) and the NDWI index and threshold ¿0.20 (overall accuracy 0.99) in the case of Sentinel-2A/B images. In Las Tablas de Daimiel wetland, a temporal analysis was carried out from 2000 to 2021 to calculate the anomalies of the water surface, precipitation, piezometric level and hydrological flow. This temporal reconstruction also made it possible to compare the results derived from Sentinel-2A/B images and Landsat 8 images. A correlation analysis was performed between the calculated anomaly indices, which revealed a non-significant correlation between the precipitation and water surface anomalies. However, the water surface anomaly index did show a statistically significant correlation with the flow anomaly and piezometric level indexes. As for the comparative analysis between Landsat-8 and Sentinel-2 images, a linear relationship was obtained between the water surface estimated by both sensors with a value of R2 = 0.87. However, the higher spatial resolution of Sentinel-2 allows the detection of smaller water masses contributing to a better analysis of the variability patterns in the study area. The information derived from this thesis presents an application of environmental interest for monitoring the state of wetlands helping to adapt management plans that lead to an adequate conservation status. / Pena Regueiro, J. (2023). Monitorización de cambios en la lámina libre de agua en humedales mediante teledetección [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/196109 / Compendio

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