This study aimed to analyze with the help of TM data - Landsat 5, the relationship between the changes in land use and the variation of temperature and surface albedo, during period winter in basin River Vieira for the years 1985, 1995 and 2010. The choice of river basin Vieira is justified because this area, located in the North of Minas Gerais, was the scene of intense and rapid population growth. So this fact led to several modifications to the systems of river basin Vieira land use, such as: rapid urban expansion, rehabilitation of degraded areas and human disturbance of natural areas. Allowing this context, the development of this work in an environment with appropriate changes in land use systems necessary for the research. The methodological procedures needed to analyze the relationship between changes in land use and the variation of temperature and surface albedo in the Rio Vieira were the following: the first procedure considered the treatment of satellite images in goal to map land use; this mapping, in turn, followed the hierarchical scheme proposed by Heymann Legend (1994). The second procedure considered the application of the algorithm semi empirical Surface Energy Balance Algorithms for Land - SEBAL, which describes the full swing of radiation on the Earth's surface from the spectral bands of visible, near infrared and thermal infrared. From an operational standpoint, the runtime of the methodology applied to the mapping of land use, since the acquisition of orbital products to validate the mappings, was relatively short. A fact that deserves attention, especially because it led to the development of a wide range of temporal information of Vieira River basin. With emphasis on the recovery of 54.79 km ² of natural vegetation in 25 years. From the viewpoint of the thermal mapping, the coefficient of variation showed a correlation between the temperature obtained by the SEBAL model and the air temperature, measured at about 1.5 m high, ranging from 0.61 to 11.38 % and an overall accuracy r ² = 0.961. This validation was highly effective in order that the data Landsat TM 5 are collected at an altitude of 705 km above the surface. The statistical validation shows that the estimate of the infrared emissivity obtained by this algorithm satisfy the need for obtaining the thermal modeling of river basin Vieira from the spectral channels of Landsat 5 TM sensor. It is recommended the SEBAL algorithm for studies seek to that analyze the spatial distribution of surface temperature data. Considering that the temperature of the surface is of great value to the understanding of various climatic phenomena. / Este trabalho objetivou analisar, com auxílio de dados TM Landsat 5, as relações entre as mudanças no uso da terra e a variação da temperatura e do albedo de superfície, no período sazonal de inverno da bacia do Rio Vieira para os anos de 1985, 1995 e 2010. A escolha da bacia do Rio Vieira se justifica porque essa área, localizada na mesorregião do Norte do Estado de Minas Gerais, foi palco de um rápido e intenso crescimento populacional. De forma que esse fato proporcionou várias modificações nos sistemas de uso da terra dessa bacia, como por exemplo: rápida expansão urbana, recuperação de áreas degradadas e a antropização de áreas naturais. Permitindo, neste contexto, o desenvolvimento deste trabalho num ambiente com as devidas alterações dos sistemas de uso da terra. Os procedimentos metodológicos necessários para analisar as relações entre as mudanças no uso da terra e a variação da temperatura e do albedo de superfície na bacia do Rio Vieira foram os seguintes: o primeiro procedimento cuidou do tratamento das imagens de satélite com vistas ao mapeamento do uso da terra; esse mapeamento, por sua vez, obedeceu ao esquema hierárquico de legenda proposto por Heymann (1994). O segundo procedimento considerou a aplicação do algoritmo semiempírico Surface Energy Balance Algorithms for Land SEBAL, o qual descreve o balanço completo de radiação sobre a superfície da Terra a partir das bandas espectrais do visível, infravermelho próximo e infravermelho termal. Do ponto de vista operacional, o tempo de execução da metodologia aplicada ao mapeamento do uso da terra, desde a aquisição dos produtos orbitais até a validação dos mapeamentos, foi relativamente curto. Fato que merece destaque, sobretudo, porque permitiu a elaboração de uma vasta gama de informações temporais da bacia do Rio Vieira. Com destaque para a recuperação de 54,79 km² de vegetação natural em 25 anos. Do ponto de vista do mapeamento termal, o coeficiente de variação apontou uma correlação entre os dados de temperatura obtidos pelo modelo SEBAL e os dados de temperatura do ar, medidos a aproximadamente 1,5m do solo, variando de 0,61 e 11,38% e uma correlação geral em r² = 0,961. Essa validação se mostrou altamente eficiente, tendo em vista que os dados do TM Landsat 5 são coletados a uma altitude de 705 km em relação à superfície. A validação estatística permite concluir que a estimativa da emissividade infravermelha obtida pelo presente algoritmo satisfez a necessidade de obtenção da modelagem térmica da bacia do Rio Vieira a partir dos canais espectrais do sensor TM Landsat 5. Desta forma, recomenda-se o algoritmo SEBAL para estudos que busquem analisar a espacialização dos dados de temperatura de superfície. Tendo em vista que a temperatura dos alvos da superfície é de grande valia para a compreensão de vários fenômenos climáticos. / Mestre em Geografia

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study aimed to estimate the radiation balance terms and the daily evapotranspiration (ET) through (TM) - Landsat 5 images and supplemental data available at a meteorological station located in the study area. The study area occupies part of the municipalities: Poço Redondo city and Canindé do São Francisco city in Sergipe State, as part of the lower São Francisco. Setting up a tributary of the right bank of the São Francisco River. The Jacare River basin rises near the border of Bahia/Sergipe state in Bonito mountain and has a length of 73.5 km Hydrological basin area is 943.9 km2, the perimeter of the area is 142.7 km. Therefore, we used two images obtained from the National Institute for Space Research (INPE) for the day October 17, 1999(day 290) and December 6 (day 341), 2006. The net radiation (Rn) and sensible heat (H) and soil heat (G) and latent heat (LE) fluxes were determined by the algorithm Surface Energy Balance Algorithm for Land (SEBAL). Examined the observed results that showed an average snapshot (Rn) de 585,1 e 578,7 W/m2 for days 290 and 341 respectively. The density of soil heat flux (G) which was obtained as a function of Rn, surface temperature, albedo, normalized difference vegetation index (NDVI), and parameterization proposed by Bastiaanssen (2000) showed an average of 92.4 and 111.8 W/m2 on days 290 and 341, respectively. The flux density of sensible heat (H) showed an average of 230.5 and 295.6 Wm2 in 290 and 341, respectively. The density of latent heat flux (LE), calculated as the residual energy balance equation showed an average of 260.3 and 169.3 W/m2 on days 290 and 341, respectively. The ET daily showed average values of 2.6 and 1.7 mm.day-1 for days 290 and 341, respectively. / O presente trabalho teve por objetivo estimar os componentes do balanço de radiação (Rn) e a evapotranspiração diária (ET), através de imagens TM - Landsat 5 e dados complementares disponíveis em estação meteorológica localizada na região de estudo. A área estudada ocupa parte dos municípios de Poço Redondo e Canindé do São Francisco no Estado de Sergipe fazendo parte do baixo São Francisco Sergipano, configurando-se num afluente da margem direita do rio São Francisco. O rio Jacaré nasce próximo à fronteira Bahia/Sergipe, na serra do Bonito. A área da bacia é de 943,98 km2 e o perímetro da área é de 142,77 km. Foram utilizadas duas imagens para os dias 17 de outubro de 1999 (dia 290) e 07 de dezembro de 2006 (dia 341). O saldo de radiação (Rn) e os fluxos de calor sensível (H) e calor no solo (G) e calor latente (LE) foram determinados por meio do algoritmo Surface Energy Balance Algorithm for Land (SEBAL). Pelos resultados, observou-se que o Rn instantâneo apresentou na área de estudo médias de 585,1 e 578,7 W/m2, para os dias 290 e 341, respectivamente. A densidade de fluxo de calor no solo (G), que foi obtido em função de Rn, temperatura da superfície, albedo, Índice de Vegetação por Diferença Normalizada (NDVI) e parametrização proposta por Bastiaanssen (2000), apresentou médias de 92,5 e 111,8 W/m2 nos dias 290 e 341, respectivamente. A densidade de fluxo de calor sensível (H) apresentou médias de 230,5 e 295,6 W/m2 nos 290 e 341, respectivamente. A densidade de fluxo de calor latente (LE), calculado como resíduo da equação do balanço de energia, apresentou médias de 260,3 e 169,3 W/m2, nos dias 290 e 341, respectivamente. A ET diária apresentou valores médios de 2,6 e 1,7 mm.dia-1, para os dias 290 e 341, respectivamente.

Policy makers adopt irrigated agriculture for food security, since irrigation doubles crop production. Therefore, the development of large irrigation systems has a long history in many places worldwide. Although large-scale irrigation schemes play an important role in improving food security, many schemes, especially in Africa, do not yield the expected outcomes. This is related to poor water management, which is generally due to a lack of effective evaluation and monitoring. The objective of this study, therefore, is to propose a new methodology to assess, evaluate and monitor large-scale irrigation systems. Information on irrigation indicators is needed to enable the evaluation of irrigation performance. The evaluation is the first and the most significant step in providing information about how it is performing. After reviewing extensive literature, a list of indicators related to the performance of irrigation, rainwater supply and productivity is suggested. The irrigation efficiency indicators Relative Irrigation Supply (RIS) and Relative Water Supply (RWS) are selected. Potential rainwater supply to crops can be tested based on the Moisture Availability Index (MAI) and the Ratio of Moisture Availability (RMA). Water productivity can be assessed by Crop Yield (Y) and Water Use Efficiency (WUE). However, the central problem facing large-scale irrigation schemes is always the lack of data, which calls for the development of a new method of data acquisition that allows evaluation and monitoring. Remote Sensing (RS) technology makes it possible to retrieve data across large areas. Two different approaches via RS, the Normalized Difference Vegetation Index (NDVI) and Actual Evapotranspiration (ETa), can be utilized for monitoring. The well-known Vegetation Condition Index (VCI), derived from the NDVI, is modified (MVCI) to allow a qualitative spatio-temporal assessment of irrigation efficiency. MVCI takes into account crop response to water availability, while ETa indicates whether water is used as intended. Furthermore, the assessment of the possible hydrological impact of the irrigation system should be considered in the evaluation and monitoring process. The Sudanese Gezira Scheme of 8,000 square kilometers in the Nile Basin, where performance evaluation and monitoring are absent or poorly conducted, is no exception. This research takes the large-scale irrigation of the Gezira Scheme as a case study, as it is the largest scheme, not only in the Nile Basin but also in the world, under single management. The first long-term historical evaluation of the scheme is conducted for the period 1961–2012 rather than only on a short-time scale as is the common practice. An increase in RIS and RWS values from 1.40 and 1.70 to 2.23 and 2.60, respectively, since the 1993/94 season shows decreasing irrigation efficiency. MAI and RMA for summer crops indicate a promising rainfall contribution to irrigation in July and August. The Gezira Scheme achieves low yield and WUE in comparison to many irrigation schemes of the globe. Low productivity is mainly due to poor distribution and irrigation mismanagement. This is indicated by the 15-year MVCI spatio-temporal analysis, which shows that the northern part of the scheme experiences characteristic drought during the summer crop season. Although MVCI can be considered a monitoring tool, the index does not deduct the soil water content, and water could be wasted and available in other ways (e.g. water depressions). Spatio-temporal information for ETa is required to better quantify water depletion and establish links between land use and water allocation. However, several RS models have been developed for estimating ETa. Thus, improving the understanding of performance of such models in arid climates, as well as large-scale irrigation schemes, is taken into account in this study. Four different models based on the energy balance method, the Surface Energy Balance Algorithm for Land (SEBAL), Mapping EvapoTranspiration at High Resolution with Internalized Calibration (METRIC™), Simplified Surface Energy Balance (SSEB) and MOD16 ET are applied in order to determine the optimal approach for obtaining ETa. Outputs from these models are compared to actual water balance (WB) estimates during the 2004/05 season at field scale. Several statistical measures are evaluated, and a score is given for each model in order to select the best-performing model. Based on ranking criteria, SSEB gives the best performance and is seen as a suitable operational ETa model for the scheme. SSEB subsequently is applied for summer and winter crop seasons for the period 2000–2014. Unfortunately, one of the limitations faced in the current research is the absence of validation data on a regional scale. Therefore, the assessment focuses on spatial distribution and trends rather than absolute values. As with the MVCI distribution, the seasonal ETa for the Gezira Scheme is higher in the southern and central parts than in the northern part. This confirms the robustness of the developed MVCI. To avoid using absolute values of ETa, the ratio of ETa from agricultural areas (ETagr) to the total evapotranspiration (ET) from the scheme (ETsum) is calculated. The ETagr/ETsum ratio shows a descending trend over recent years, indicating that the water is available but not being utilized for agricultural production. This study shows that SSEB is also useful for identifying the location of water losses on a daily basis. Around 80 channels are identified as having leakage problems for the 2013/14 crop season. Such information is very useful for reducing losses at the scheme. In addition, Rainwater Harvesting (WH) is addressed and found to be applicable as an alternative solution for accounting for rainfall in irrigation. It is seen that these management scenarios could save water and increase the overall efficiency of the scheme. It is possible to save 68 million cubic meters of water per year when the overall irrigation efficiency of the scheme is improved by only 1%. A level of efficiency of 75% is predicted from the proposed management scenarios, which could save about 2.6 billion cubic meters of water per year. In conclusion, the present study has developed an innovative method of identifying the problems of large-scale schemes as well as proposing management scenarios to enhance irrigation water management practice. Improved agricultural water management in terms of crop, water and land management can increase food production, thereby alleviating poverty and hunger in an environmentally sustainable manner.

Policy makers adopt irrigated agriculture for food security, since irrigation doubles crop production. Therefore, the development of large irrigation systems has a long history in many places worldwide. Although large-scale irrigation schemes play an important role in improving food security, many schemes, especially in Africa, do not yield the expected outcomes. This is related to poor water management, which is generally due to a lack of effective evaluation and monitoring. The objective of this study, therefore, is to propose a new methodology to assess, evaluate and monitor large-scale irrigation systems. Information on irrigation indicators is needed to enable the evaluation of irrigation performance. The evaluation is the first and the most significant step in providing information about how it is performing. After reviewing extensive literature, a list of indicators related to the performance of irrigation, rainwater supply and productivity is suggested. The irrigation efficiency indicators Relative Irrigation Supply (RIS) and Relative Water Supply (RWS) are selected. Potential rainwater supply to crops can be tested based on the Moisture Availability Index (MAI) and the Ratio of Moisture Availability (RMA). Water productivity can be assessed by Crop Yield (Y) and Water Use Efficiency (WUE). However, the central problem facing large-scale irrigation schemes is always the lack of data, which calls for the development of a new method of data acquisition that allows evaluation and monitoring. Remote Sensing (RS) technology makes it possible to retrieve data across large areas. Two different approaches via RS, the Normalized Difference Vegetation Index (NDVI) and Actual Evapotranspiration (ETa), can be utilized for monitoring. The well-known Vegetation Condition Index (VCI), derived from the NDVI, is modified (MVCI) to allow a qualitative spatio-temporal assessment of irrigation efficiency. MVCI takes into account crop response to water availability, while ETa indicates whether water is used as intended. Furthermore, the assessment of the possible hydrological impact of the irrigation system should be considered in the evaluation and monitoring process. The Sudanese Gezira Scheme of 8,000 square kilometers in the Nile Basin, where performance evaluation and monitoring are absent or poorly conducted, is no exception. This research takes the large-scale irrigation of the Gezira Scheme as a case study, as it is the largest scheme, not only in the Nile Basin but also in the world, under single management. The first long-term historical evaluation of the scheme is conducted for the period 1961–2012 rather than only on a short-time scale as is the common practice. An increase in RIS and RWS values from 1.40 and 1.70 to 2.23 and 2.60, respectively, since the 1993/94 season shows decreasing irrigation efficiency. MAI and RMA for summer crops indicate a promising rainfall contribution to irrigation in July and August. The Gezira Scheme achieves low yield and WUE in comparison to many irrigation schemes of the globe. Low productivity is mainly due to poor distribution and irrigation mismanagement. This is indicated by the 15-year MVCI spatio-temporal analysis, which shows that the northern part of the scheme experiences characteristic drought during the summer crop season. Although MVCI can be considered a monitoring tool, the index does not deduct the soil water content, and water could be wasted and available in other ways (e.g. water depressions). Spatio-temporal information for ETa is required to better quantify water depletion and establish links between land use and water allocation. However, several RS models have been developed for estimating ETa. Thus, improving the understanding of performance of such models in arid climates, as well as large-scale irrigation schemes, is taken into account in this study. Four different models based on the energy balance method, the Surface Energy Balance Algorithm for Land (SEBAL), Mapping EvapoTranspiration at High Resolution with Internalized Calibration (METRIC™), Simplified Surface Energy Balance (SSEB) and MOD16 ET are applied in order to determine the optimal approach for obtaining ETa. Outputs from these models are compared to actual water balance (WB) estimates during the 2004/05 season at field scale. Several statistical measures are evaluated, and a score is given for each model in order to select the best-performing model. Based on ranking criteria, SSEB gives the best performance and is seen as a suitable operational ETa model for the scheme. SSEB subsequently is applied for summer and winter crop seasons for the period 2000–2014. Unfortunately, one of the limitations faced in the current research is the absence of validation data on a regional scale. Therefore, the assessment focuses on spatial distribution and trends rather than absolute values. As with the MVCI distribution, the seasonal ETa for the Gezira Scheme is higher in the southern and central parts than in the northern part. This confirms the robustness of the developed MVCI. To avoid using absolute values of ETa, the ratio of ETa from agricultural areas (ETagr) to the total evapotranspiration (ET) from the scheme (ETsum) is calculated. The ETagr/ETsum ratio shows a descending trend over recent years, indicating that the water is available but not being utilized for agricultural production. This study shows that SSEB is also useful for identifying the location of water losses on a daily basis. Around 80 channels are identified as having leakage problems for the 2013/14 crop season. Such information is very useful for reducing losses at the scheme. In addition, Rainwater Harvesting (WH) is addressed and found to be applicable as an alternative solution for accounting for rainfall in irrigation. It is seen that these management scenarios could save water and increase the overall efficiency of the scheme. It is possible to save 68 million cubic meters of water per year when the overall irrigation efficiency of the scheme is improved by only 1%. A level of efficiency of 75% is predicted from the proposed management scenarios, which could save about 2.6 billion cubic meters of water per year. In conclusion, the present study has developed an innovative method of identifying the problems of large-scale schemes as well as proposing management scenarios to enhance irrigation water management practice. Improved agricultural water management in terms of crop, water and land management can increase food production, thereby alleviating poverty and hunger in an environmentally sustainable manner.

Made available in DSpace on 2015-05-14T12:09:36Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 5605900 bytes, checksum: 3d25379d8d6eb2b9a5d187b806036974 (MD5) Previous issue date: 2014-05-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study analyzed the influence of the soil s usage and occupation on the surface temperature variance and on radiation balance in Joao Pessoa city. For that, it was used remote sensing techniques, Geographic Information Systems and SEBAL algorithm. For the soil s usage and occupation classification, and the determination of emissivity, albedo, NDVI, IAF and SAVI were used, and for surface temperature and radiation balance, Landsat 5-TM satellite s images was used, referring to november 5, 1991; August 26, 2006; and October 8, 2010.The usage and occupation of João Pessoa s soil analyses showed that during the years of 1991, 2006 and 2010, the city had a considerable increase of the urban mesh above herbaceous vegetation and bare soil. The surface temperature has shown greater values above urban area and bare soil on the last three years, above all on 1991 which obtained maximum temperature values, with average of 31.4°C above urban area and 31.1°C above bare soil. The radiation balance images and statistic values has shown that the highest values of Rn was founded above arboreal/shrubby vegetation and water for all the years, above all on 2010 when was obtained the highest values of Rn for all soil usages, which the averages were 717.5W/m² above water, and 703.2W/m² above arboreal/shrubby vegetation. The relationship between the albedo of soil usages (urban and herbaceous vegetation) with the temperature and radiation balance, has shown that it was satisfactory, indicating the method efficiency for estimate the quoted parameters with the targets analyzed for João Pessoa city. The temperature and radiation balance results found on this study, obtained through SEBAL and satellite images, allows to conclude that the values has shown match variances with those showed in the literature for similar soil usages / Este trabalho analisou a influência do uso e ocupação do solo na variabilidade da temperatura da superfície e no saldo de radiação na cidade de João Pessoa. Para tanto, foram utilizadas técnicas de sensoriamento remoto, Sistemas de Informações Geográficas e o algoritmo SEBAL. Para a classificação do uso e ocupação do solo e a determinação dos valores de emissividade, albedo, NDVI, IAF, SAVI, temperatura de superfície e saldo de radiação à superfície, foram utilizadas imagens do satélite Landsat 5-TM referente aos dias 5 de novembro de 1991, 26 de agosto de 2006 e 8 de outubro de 2010.A análise do uso e ocupação do solo da cidade de João Pessoa apontou que no decorrer dos anos de 1991, 2006 e 2010 a cidade teve um considerável crescimento da malha urbana sobre áreas de vegetação herbácea e solo exposto. A temperatura da superfície apresentou maiores valores sobre área urbana e solo exposto nos três anos, sobretudo em 1991 que obteve valores máximos de temperatura, com média de 31,4ºC sobre área urbana e de 31,1ºC sobre solo exposto. As imagens do saldo de radiação e os valores estatísticos mostraram que os maiores valores de Rn foram encontrados sobre vegetação arbórea/arbustiva e água para todos os anos, sobretudo em 2010 onde foram obtidos os maiores valores de Rn para todos os usos do solo, cujas médias foram de 717,5W/m² sobre água e 703,2W/m² sobre vegetação arbórea/arbustiva. A relação entre o albedo dos usos do solo (urbano e vegetação herbácea) com a temperatura e o saldo de radiação, mostrou-se satisfatórios, indicando a eficiência do método na estimativa dos parâmetros citados com os alvos analisados para a cidade de João Pessoa. Os resultados de temperatura e saldo de radiação encontrados nesta pesquisa, obtidos através do SEBAL e das imagens de satélite, permitem concluir que os valores apontaram variações condizentes com os apresentados na literatura para usos do solo similares