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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.
11

Geospatial Analysis of the Impact of Land-Use and Land Cover Change on Maize Yield in Central Nigeria

Wegbebu, Reynolds 05 June 2023 (has links)
No description available.
12

Performance Assessment and Management of Groundwater in an Irrigation Scheme by Coupling Remote Sensing Data and Numerical Modeling Approaches

Usman, Muhammad 05 July 2016 (has links) (PDF)
The irrigated agriculture in the Lower Chenab Canal (LCC) of Pakistan is characterized by huge water utilization both from surface and groundwater resources. Need of utilization of water from five rivers in Punjab province along with accelerated population growth has forced the construction of world’s largest irrigation network. Nevertheless, huge irrigation infrastructure, together with inappropriate drainage infrastructure, led to a build-up of shal-low groundwater levels, followed by waterlogging and secondary salinization in the soil profile. Following this era, decreased efficiency of irrigation supply system along with higher food demands had increased burdens on groundwater use, which led to a drop in groundwater levels in major parts of LCC. Previous studies in the study region revealed lacking management and maintenance of irrigation system, inflexible irrigation strategies, poor linkages between field level water supply and demands. No future strategy is present or under consideration to deal with this long time emerged groundwater situation particularly under unchanged irrigation water supply and climate change. Therefore, there is an utmost importance to assess the current profile of water use in the irrigation scheme and to device some workable strategies under future situations of land use and climate change. This study aims to investigate the spatio-temporal status of water utilization and performance of irrigation system using remote sensing data and techniques (SEBAL) in combination with other point data. Different irrigation performance indicators including equity, adequacy and reliability using evaporation fraction as main input parameter are utilized. Current profiles of land use/land cover (LULC) areas are assessed and their change detections are worked out to establish realistic future scenarios. Spatially distributed seasonal net recharge, a very important input parameter for groundwater modeling, is estimated by employing water balance approaches using spatial data from remote sensing and local norms. Such recharge results are also compared with a water table fluctuation approach. Following recharge estimation, a regional 3-D groundwater flow model using FEFLOW was set up. This model was calibrated by different approaches ranging from manual to automated pilot point (PP) approach. Sensitivity analysis was performed to see the model response against different model input parameters and to identify model regions which demand further improvements. Future climate parameters were downscaled to establish scenarios by using statistical downscaling under IPCC future emission scenarios. Modified recharge raster maps were prepared under both LULC and climate change scenarios and were fed to the groundwater model to investigate groundwater dynamics. Seasonal consumptive water use analysis revealed almost double use for kharif as compared to rabi cropping seasons with decrease from upper LCC to lower regions. Intra irrigation subdivision analysis of equity, an important irrigation performance indicator, shows less differences in water consumption in LCC. However, the other indicators (adequacy and reliability) indicate that the irrigation system is neither adequate nor reliable. Adequacy is found more pronounced during kharif as compared to rabi seasons with aver-age evaporation fraction of 0.60 and 0.67, respectively. Similarly, reliability is relatively higher in upper LCC regions as compared to lower regions. LULC classification shows that wheat and rice are major crops with least volatility in cultivation from season to season. The results of change detection show that cotton exhibited maximum positive change while kharif fodder showed maximum negative change during 2005-2012. Transformation of cotton area to rice cultivation is less conspicuous. The water consumption in upper LCC regions with similar crops is relatively higher as compared to lower regions. Groundwater recharge results revealed that, during the kharif cropping seasons, rainfall is the main source of recharge followed by field percolation losses, while for rabi cropping seasons, canal seepage remains the major source. Seasonal net groundwater recharge is mainly positive during all kharif seasons with a gradual increase in groundwater level in major parts of LCC. Model optimization indicates that PP is more flexible and robust as compared to manual and zone based approaches. Different statistical indicators show that this method yields reliable calibration and validation as values of Nash Sutcliffe Efficiency are 0.976 and 0.969, % BIAS are 0.026 and -0.205 and root mean square errors are 1.23 m and 1.31 m, respectively. Results of model output sensitivity suggest that hydraulic conductivity is a more influential parameter in the study area than drain/fillable porosity. Model simulation results under different scenarios show that rice cultivation has the highest impact on groundwater levels in upper LCC regions whereas major negative changes are observed for lower parts under decreased kharif fodder area in place of rice, cotton and sugarcane. Fluctuations in groundwater level among different proposed LULC scenarios are within ±1 m, thus showing a limited potential for groundwater management. For future climate scenarios, a rise in groundwater level is observed for 2011 to 2025 under H3A2 emission regime. Nevertheless, a drop in groundwater level is expected due to increased crop consumptive water use and decreased precipitations under H3A2 scenario for the periods 2026-2035 and 2036-2045. Although no imminent threat of groundwater shortage is anticipated, there is an opportunity for developing groundwater resources in the lower model regions through water re-allocation that would be helpful in dealing water shortages. The groundwater situation under H3B2 emission regime is relatively complex due to very low expectation of rise in groundwater level through precipitation during 2011-2025. Any positive change in groundwater under such scenarios is mainly associated with changes in crop consumptive water uses. Consequently, water management under such situation requires revisiting of current cropping patterns as well as augmenting water supply through additional surface water resources.
13

Mapping and Assessment of Land Use/Land Cover Using Remote Sensing and GIS in North Kordofan State, Sudan

Dafalla Mohamed, Mohamed Salih 20 February 2007 (has links) (PDF)
Sudan as a Sahelian country faced numerous drought periods resulting in famine and mass immigration. Spatial data on dynamics of land use and land cover is scarce and/or almost nonexistent. The study area in the North Kordofan State is located in the centre of Sudan and falls in the Sahelian eco-climatic zone. The region generally yields reasonable harvests of rainfed crops and the grasslands supports plenty of livestock. But any attempts to develop medium- to longterm strategies of sustainable land management have been hampered by the impacts of drought and desertification over a long period of time. This study aims to determine and analyse the dynamics of change of land use/land cover classes. The study attempts also to improve classification accuracy by using different data transformation methods like PCA, TCA and CA. In addition it tries to investigate the most reliable methods of pre-classification and/or post-classification change detection. The research also attempts to assess the desertification process using vegetation cover as an indicator. Preliminary mapping of major soil types is also an objective of this study. Landsat data of MSS 187/51 acquired on 01.01.1973 and ETM+ 174/51 acquired on 16.01.2001 were used. Visual interpretation in addition to digital image processing was applied to process the imagery for determining land use/land cover classes for the recent and reference image. Pre- and post-classification change detection methods were used to detect changes in land use/land cover classes in the study area. Pre-classification methods include image differencing, PC and Change Vector Analysis. Georeferenced soil samples were analysed to measure physical and chemical parameters. The measured values of these soil properties were integrated with the results of land use/ land cover classification. The major LULC classes present in the study area are forest, farm on sand, farm on clay, fallow on sand, fallow on clay, woodyland, mixed woodland, grassland, burnt/wetland and natural water bodies. Farming on sandy and clay soils constitute the major land use in the area, while mixed woodland constitutes the major land cover. Classification accuracy is improved by adopting data transformation by PCA, TCA and CA. Pre-classification change detection methods show indistinct and sketchy patterns of change but post-classification method shows obvious and detailed results. Vegetation cover changes were illustrated by use of NDVI. In addition preliminary soil mapping by using mineral indices was done based on ETM+ imagery. Distinct patterns of clay, gardud and sand areas could be classified. Remote sensing methods used in this study prove a high potential to classify land use/land cover as well as soil classes. Moreover the remote sensing methods used confirm efficiency for detecting changes in LULC classes and vegetation cover during the addressed period.
14

Performance Assessment and Management of Groundwater in an Irrigation Scheme by Coupling Remote Sensing Data and Numerical Modeling Approaches

Usman, Muhammad 08 April 2016 (has links)
The irrigated agriculture in the Lower Chenab Canal (LCC) of Pakistan is characterized by huge water utilization both from surface and groundwater resources. Need of utilization of water from five rivers in Punjab province along with accelerated population growth has forced the construction of world’s largest irrigation network. Nevertheless, huge irrigation infrastructure, together with inappropriate drainage infrastructure, led to a build-up of shal-low groundwater levels, followed by waterlogging and secondary salinization in the soil profile. Following this era, decreased efficiency of irrigation supply system along with higher food demands had increased burdens on groundwater use, which led to a drop in groundwater levels in major parts of LCC. Previous studies in the study region revealed lacking management and maintenance of irrigation system, inflexible irrigation strategies, poor linkages between field level water supply and demands. No future strategy is present or under consideration to deal with this long time emerged groundwater situation particularly under unchanged irrigation water supply and climate change. Therefore, there is an utmost importance to assess the current profile of water use in the irrigation scheme and to device some workable strategies under future situations of land use and climate change. This study aims to investigate the spatio-temporal status of water utilization and performance of irrigation system using remote sensing data and techniques (SEBAL) in combination with other point data. Different irrigation performance indicators including equity, adequacy and reliability using evaporation fraction as main input parameter are utilized. Current profiles of land use/land cover (LULC) areas are assessed and their change detections are worked out to establish realistic future scenarios. Spatially distributed seasonal net recharge, a very important input parameter for groundwater modeling, is estimated by employing water balance approaches using spatial data from remote sensing and local norms. Such recharge results are also compared with a water table fluctuation approach. Following recharge estimation, a regional 3-D groundwater flow model using FEFLOW was set up. This model was calibrated by different approaches ranging from manual to automated pilot point (PP) approach. Sensitivity analysis was performed to see the model response against different model input parameters and to identify model regions which demand further improvements. Future climate parameters were downscaled to establish scenarios by using statistical downscaling under IPCC future emission scenarios. Modified recharge raster maps were prepared under both LULC and climate change scenarios and were fed to the groundwater model to investigate groundwater dynamics. Seasonal consumptive water use analysis revealed almost double use for kharif as compared to rabi cropping seasons with decrease from upper LCC to lower regions. Intra irrigation subdivision analysis of equity, an important irrigation performance indicator, shows less differences in water consumption in LCC. However, the other indicators (adequacy and reliability) indicate that the irrigation system is neither adequate nor reliable. Adequacy is found more pronounced during kharif as compared to rabi seasons with aver-age evaporation fraction of 0.60 and 0.67, respectively. Similarly, reliability is relatively higher in upper LCC regions as compared to lower regions. LULC classification shows that wheat and rice are major crops with least volatility in cultivation from season to season. The results of change detection show that cotton exhibited maximum positive change while kharif fodder showed maximum negative change during 2005-2012. Transformation of cotton area to rice cultivation is less conspicuous. The water consumption in upper LCC regions with similar crops is relatively higher as compared to lower regions. Groundwater recharge results revealed that, during the kharif cropping seasons, rainfall is the main source of recharge followed by field percolation losses, while for rabi cropping seasons, canal seepage remains the major source. Seasonal net groundwater recharge is mainly positive during all kharif seasons with a gradual increase in groundwater level in major parts of LCC. Model optimization indicates that PP is more flexible and robust as compared to manual and zone based approaches. Different statistical indicators show that this method yields reliable calibration and validation as values of Nash Sutcliffe Efficiency are 0.976 and 0.969, % BIAS are 0.026 and -0.205 and root mean square errors are 1.23 m and 1.31 m, respectively. Results of model output sensitivity suggest that hydraulic conductivity is a more influential parameter in the study area than drain/fillable porosity. Model simulation results under different scenarios show that rice cultivation has the highest impact on groundwater levels in upper LCC regions whereas major negative changes are observed for lower parts under decreased kharif fodder area in place of rice, cotton and sugarcane. Fluctuations in groundwater level among different proposed LULC scenarios are within ±1 m, thus showing a limited potential for groundwater management. For future climate scenarios, a rise in groundwater level is observed for 2011 to 2025 under H3A2 emission regime. Nevertheless, a drop in groundwater level is expected due to increased crop consumptive water use and decreased precipitations under H3A2 scenario for the periods 2026-2035 and 2036-2045. Although no imminent threat of groundwater shortage is anticipated, there is an opportunity for developing groundwater resources in the lower model regions through water re-allocation that would be helpful in dealing water shortages. The groundwater situation under H3B2 emission regime is relatively complex due to very low expectation of rise in groundwater level through precipitation during 2011-2025. Any positive change in groundwater under such scenarios is mainly associated with changes in crop consumptive water uses. Consequently, water management under such situation requires revisiting of current cropping patterns as well as augmenting water supply through additional surface water resources.:ABSTRACT VIII ZUSAMMENFASSUNG X ACRONYMS 1 Chapter 1 3 GENERAL INTRODUCTION 3 1 Groundwater for irrigated agriculture 3 2 Groundwater development in Pakistan 4 3 Study area 6 4 History of groundwater use in the study area 7 5 Research agenda 8 5.1 Problem statement 8 5.2 Objectives and scope of the study 9 Chapter 2 12 OVERVIEW OF PUBLICATIONS 12 Chapter 3 16 GENERAL CONCLUSIONS AND POLICY RECOMMENDATIONS 16 REFERENCES 20 ANNEXES 23 ACKNOWLEDGEMENTS 123
15

Mapping and Assessment of Land Use/Land Cover Using Remote Sensing and GIS in North Kordofan State, Sudan

Dafalla Mohamed, Mohamed Salih 02 February 2007 (has links)
Sudan as a Sahelian country faced numerous drought periods resulting in famine and mass immigration. Spatial data on dynamics of land use and land cover is scarce and/or almost nonexistent. The study area in the North Kordofan State is located in the centre of Sudan and falls in the Sahelian eco-climatic zone. The region generally yields reasonable harvests of rainfed crops and the grasslands supports plenty of livestock. But any attempts to develop medium- to longterm strategies of sustainable land management have been hampered by the impacts of drought and desertification over a long period of time. This study aims to determine and analyse the dynamics of change of land use/land cover classes. The study attempts also to improve classification accuracy by using different data transformation methods like PCA, TCA and CA. In addition it tries to investigate the most reliable methods of pre-classification and/or post-classification change detection. The research also attempts to assess the desertification process using vegetation cover as an indicator. Preliminary mapping of major soil types is also an objective of this study. Landsat data of MSS 187/51 acquired on 01.01.1973 and ETM+ 174/51 acquired on 16.01.2001 were used. Visual interpretation in addition to digital image processing was applied to process the imagery for determining land use/land cover classes for the recent and reference image. Pre- and post-classification change detection methods were used to detect changes in land use/land cover classes in the study area. Pre-classification methods include image differencing, PC and Change Vector Analysis. Georeferenced soil samples were analysed to measure physical and chemical parameters. The measured values of these soil properties were integrated with the results of land use/ land cover classification. The major LULC classes present in the study area are forest, farm on sand, farm on clay, fallow on sand, fallow on clay, woodyland, mixed woodland, grassland, burnt/wetland and natural water bodies. Farming on sandy and clay soils constitute the major land use in the area, while mixed woodland constitutes the major land cover. Classification accuracy is improved by adopting data transformation by PCA, TCA and CA. Pre-classification change detection methods show indistinct and sketchy patterns of change but post-classification method shows obvious and detailed results. Vegetation cover changes were illustrated by use of NDVI. In addition preliminary soil mapping by using mineral indices was done based on ETM+ imagery. Distinct patterns of clay, gardud and sand areas could be classified. Remote sensing methods used in this study prove a high potential to classify land use/land cover as well as soil classes. Moreover the remote sensing methods used confirm efficiency for detecting changes in LULC classes and vegetation cover during the addressed period.
16

Land use/land cover change prediction in Dak Nong Province based on remote sensing and Markov Chain Model and Cellular Automata

Nguyen, Thi Thanh Huong, Ngo, Thi Thuy Phuong 05 February 2019 (has links)
Land use and land cover changes (LULCC) including deforestation for agricultural land and others are elements that contribute on global environmental change. Therefore understanding a trend of these changes in the past, current, and future is important for making proper decisions to develop in a sustainable way. This study analyzed land use and land cover (LULC) changes over time for Tuy Duc district belonging to Dak Nong province based on LULC maps classified from a set of multidate satellite images captured in year 2003, 2006, 2009, and 2013 (SPOT 5 satellite images). The LULC spatio-temporal changes in the area were classified as perennial agriculture, cropland, residential area, grassland, natural forest, plantation and water surface. Based on these changes over time, potential LULC in 2023 was predicted using Cellular Automata (CA)–Markov model. The predicted results of the change in LULC in 2023 reveal that the total area of forest will lose 9,031ha accounting of 50% in total area of the changes. This may be mainly caused by converting forest cover to agriculture (account for 28%), grassland (12%) and residential area (9%). The findings suggest that the forest conversion needs to be controlled and well managed, and a reasonable land use plan should be developed in a harmonization way with forest resources conservation. / Thay đổi sử dụng đất và thảm phủ (LULCC) bao gồm cả việc phá rừng để phát triển nông nghiệp và vì các mục đích khác là tác nhân đóng góp vào biến đổi môi trường toàn cầu. Vì vậy hiểu biết về khuynh hướng của sự thay đổi này trong quá khứ, hiện tại và tương lai là quan trọng để đưa ra những quyết định dúng đắn để phát triển bền vững. Nghiên cứu đã phân tích LULCC trong thời gian qua dựa vào các bản đồ sử dụng đất và thảm phủ (LULC) đã được phân loại từ một loạt ảnh vệ tinh đa phổ được thu chụp vào năm 2003, 2006, 2009 (ảnh SPOT 5). Những thay đổi LULC theo thời gian và không gian trong khu vực được phân loại thành đất nông nghiệp với cây dài ngày, cây ngắn ngày, thổ cư, trảng cỏ cây bụi, rừng tự nhiên, rừng trồng và mặt nước. Dựa trên sự thay đổi này theo thời gian, LULC tiềm năng cho năm 2023 đã được dự báo bằng cách sử dụng mô hình CAMarkov. Kết quả dự báo LULCC năm 2023 đã cho thấy tổng diện tích rừng bị mất khoảng 9,031 ha chiếm 50% trong tổng số diện tích thay đổi. Điều này chủ yếu là do chuyển đổi từ rừng tự nhiên sang canh tác nông nghiệp (chiếm 28%), trảng cỏ cây bụi (12%) và khu dân cư (9%). Kết quả cho thấy việc chuyển đổi rừng cần phải được kiểm soát và quản lý tốt và một kế hoạch sử dụng đất hợp lý cần được xây dựng trong sự hài hòa với bảo tồn tài nguyên rừng.
17

Water security and ecosystem-based adaptation in the headwaters of Cantareira Water Supply System, Brazil / Segurança hídrica e adaptação baseada em ecossistemas nas bacias de cabeceira do Sistema Cantareira, Brasil

Taffarello, Denise 26 August 2016 (has links)
Water quantity, availability and, particularly, quality of Brazilian freshwater is under progessive degradation due to Anthropocene\'s environmental changing conditions. Strategies of Ecosystem-based Adaptation (EbA) are essential to mitigate these impacts. This Ph.D. thesis proposes a new model of water resources management, thereby integrating selfpurification and ecohydrologic processes to evaluate ecosystem services from watershed under change. In Chapter 2, this thesis examinates the payment for hydrologic cosystem services (Water-PES) in Brazilian Atlantic Forest and points ecohydrologic variables useful for assessing and further valuing hydrologic services. In Chapter 3, this thesis discusses proposals for freshwater monitoring plan which integrate quali-quantitative aspects for EbA and Water-PES projects. Therefore, in Chapter 4 experimental quali-quantative freshwater data from in-situ field observations are investigated according land-use/land-cover (LULC) in headwaters of water supply systems. In Chapter 5, through simulated impacts on freshwater yield from scenarios of LULC change, the grey water footprint (greyWF) is assessed, as well as environmental sustainability of sub-basins is depicted from a new ecohydrologic index for assessing hydrologic services. The methodology is performed using through field sampling and lab-analysing of physico-chemical, biologic and hydraulic variables in nested sub-basins draining to the Cantareira Water Supply System, in Sao Paulo and Minas Gerais states, Brazil. These areas participate in the Water-PES projects Water Producer/PCJ and Water Conservator at headwaters of Piracicaba watershed, during recent severe drought conditions between years 2013-15. The greyWF is estimated from outputs of time series simulated through ecohydrologic model Soil and Water Assessment Tool (SWAT). Under assumption of continuity of Water-PES projects, and using the same series of hydrometorological records for a common period (2008-2014), freshwater quali-quantitative impacts are performed through three LULC scenarios: past situation \"S1\" (year 1990), current situation \"S2\" (year 2010) and future situation \"S2+EbA\" (year 2035). From these scenarios, flow and load duration curves, mean water yields, greyWF and seasonal variabilities, were simulated. Through this research, continuous-monitoring Data Collecting Stations were installed in public-private partnership encompassing EESC/USP, ANA, CPRM, CEMADEN, SMA, TNC, WWF and local mayors. This continuous monitoring is addressed to increase the system resilience, based on better decision-making for water security, in strategic headwaters not only for water supply, but also for environmental conservation. This doctoral thesis brings contributions to a better comprehension of anthropic impacts on water resources and for strategies of EbA in front of progressive rates of losses of ecosystem services. This PhD. thesis was part of three research initiatives which partly granted activities: (1) Thematic Project FAPESP 2008/58161-1 \"Assessment of Impacts and Vulnerability to Climate Change in Brazil and Strategies for Adaptation Options\"; (2) \"INCLINE - INterdisciplinary CLimate INvEstigation Center\" (NapMC/USP Núcleo de Apoio às Pesquisas em Mudanças Climáticas) and (3) \"Água Brasil\" Project, Banco do Brasil Foundation, WWF Brazil, ANA & FIPAI/EESC-USP. / A quantidade, a disponibilidade e, em particular, a qualidade da água doce está em degradação progressiva devido às mudanças ambientais no Antropoceno. Estratégias de adaptação baseadas em ecossistemas (EbA) são essenciais para reduzir estes impactos. Propõe-se um novo modelo de gerenciamento de recursos hídricos que integre a pegada hídrica cinza e processos ecohidrológicos para avaliação dos serviços hidrológicos em bacias hidrográficas sob mudanças. As etapas da pesquisa são: Capítulo 2 – análise dos projetos de pagamentos por serviços ambientais de proteção às bacias hidrográficas na Mata Atlântica brasileira e, no contexto de EbA, indicação de variáveis ecohidrológicas úteis na quantificação e futura valoração dos serviços hidrológicos; Capítulo 3 – desenvolvimento de plano de monitoramento ecohidrológico que integra aspectos qualitativos e quantitativos dos recursos hídricos para projetos de EbA; Capítulo 4 – provisão de dados experimentais de qualidade e quantidade da água, além de observações in-situ, para investigação das influências das mudanças de uso e ocupação do solo nas cabeceiras de mananciais, estratégicos para o abastecimento público e a conservação ambiental; Capítulo 5 – estimativas da pegada hídrica cinza para nitrato, fósforo total e sedimentos a partir do monitoramento de variáveis quali-quantitativas em bacias com diferentes condições de uso e ocupação de solo. Foi realizada a instalação de três Plataformas de Coleta de Dados, por meio de parceria entre EESC, ANA, CPRM, CEMADEN, SMA, TNC e WWF, visando aumentar a resiliência do sistema, decorrente de futuro aprimoramento da gestão, para a segurança hídrica. A metodologia incluiu coletas em seis diferentes períodos, durante dois anos, e análises das variáveis condutividade elétrica, cor, DQO, DBO5,20, nitrato, nitrito, nitrogênio amoniacal, fosfato, pH, turbidez, sólidos totais, coliformes termotolerantes, Escherichia coli, medidas de vazões e velocidades médias em seções transversais. O método foi aplicado em microbacias participantes dos projetos Produtor de Água/PCJ e Conservador das Águas, dentre outras, com áreas de drenagem entre 7 e 1.000 km2, que contribuem para a bacia do rio Piracicaba (12.530 km2). Dados primários, medidos em recente período de severa estiagem no Sistema Cantareira (2013-14), foram integrados aos bancos de dados de órgãos gestores federais e estaduais. A produção de água foi maior em sub-bacias menos florestadas. Foi possível aprimorar a regionalização de cargas poluidoras por área de drenagem na região do Cantareira. A pegada hídrica cinza (WF) foi estimada a partir de simulações no modelo ecohidrológico Soil and Water Assessment Tool (SWAT). Curvas de permanência de vazões e carga poluidora por área de drenagem foram elaboradas. Supondo-se a continuidade dos projetos \"Produtor de Água/PCJ\" e \"Conservador das Águas\", foram investigados os impactos de cenário futuro de uso do solo. Finalmente, foi desenvolvido novo índice ecohidrológico para quantificação dos serviços hidrológicos e avaliação a sustentabilidade das sub-bacias, a partir da pegada hídrica cinza composta. Assim, usando ferramentas de vanguarda tecnológica (SWAT e WF), a tese fornece subsídios para uma melhor compreensão dos impactos antropogênicos sobre os recursos hídricos e novas estratégias de adaptação baseada em ecossistemas, frente às progressivas taxas de perda de serviços ambientais. Esta tese esteve vinculada a três projetos de pesquisa, dos quais obteve apoio financeiro: (1) Projeto Temático FAPESP 2008/58161-1 \"Assessment of Impacts and Vulnerability to Climate Change in Brazil & Strategies for Adaptation Options\"; (2) \"INCLINE - INterdisciplinary CLimate INvEstigation Center\" (NapMC/USP) e (3) Projeto \"Água Brasil\", Fundação Banco do Brasil, WWF Brasil, ANA e FIPAI/EESC-USP.
18

Water security and ecosystem-based adaptation in the headwaters of Cantareira Water Supply System, Brazil / Segurança hídrica e adaptação baseada em ecossistemas nas bacias de cabeceira do Sistema Cantareira, Brasil

Denise Taffarello 26 August 2016 (has links)
Water quantity, availability and, particularly, quality of Brazilian freshwater is under progessive degradation due to Anthropocene\'s environmental changing conditions. Strategies of Ecosystem-based Adaptation (EbA) are essential to mitigate these impacts. This Ph.D. thesis proposes a new model of water resources management, thereby integrating selfpurification and ecohydrologic processes to evaluate ecosystem services from watershed under change. In Chapter 2, this thesis examinates the payment for hydrologic cosystem services (Water-PES) in Brazilian Atlantic Forest and points ecohydrologic variables useful for assessing and further valuing hydrologic services. In Chapter 3, this thesis discusses proposals for freshwater monitoring plan which integrate quali-quantitative aspects for EbA and Water-PES projects. Therefore, in Chapter 4 experimental quali-quantative freshwater data from in-situ field observations are investigated according land-use/land-cover (LULC) in headwaters of water supply systems. In Chapter 5, through simulated impacts on freshwater yield from scenarios of LULC change, the grey water footprint (greyWF) is assessed, as well as environmental sustainability of sub-basins is depicted from a new ecohydrologic index for assessing hydrologic services. The methodology is performed using through field sampling and lab-analysing of physico-chemical, biologic and hydraulic variables in nested sub-basins draining to the Cantareira Water Supply System, in Sao Paulo and Minas Gerais states, Brazil. These areas participate in the Water-PES projects Water Producer/PCJ and Water Conservator at headwaters of Piracicaba watershed, during recent severe drought conditions between years 2013-15. The greyWF is estimated from outputs of time series simulated through ecohydrologic model Soil and Water Assessment Tool (SWAT). Under assumption of continuity of Water-PES projects, and using the same series of hydrometorological records for a common period (2008-2014), freshwater quali-quantitative impacts are performed through three LULC scenarios: past situation \"S1\" (year 1990), current situation \"S2\" (year 2010) and future situation \"S2+EbA\" (year 2035). From these scenarios, flow and load duration curves, mean water yields, greyWF and seasonal variabilities, were simulated. Through this research, continuous-monitoring Data Collecting Stations were installed in public-private partnership encompassing EESC/USP, ANA, CPRM, CEMADEN, SMA, TNC, WWF and local mayors. This continuous monitoring is addressed to increase the system resilience, based on better decision-making for water security, in strategic headwaters not only for water supply, but also for environmental conservation. This doctoral thesis brings contributions to a better comprehension of anthropic impacts on water resources and for strategies of EbA in front of progressive rates of losses of ecosystem services. This PhD. thesis was part of three research initiatives which partly granted activities: (1) Thematic Project FAPESP 2008/58161-1 \"Assessment of Impacts and Vulnerability to Climate Change in Brazil and Strategies for Adaptation Options\"; (2) \"INCLINE - INterdisciplinary CLimate INvEstigation Center\" (NapMC/USP Núcleo de Apoio às Pesquisas em Mudanças Climáticas) and (3) \"Água Brasil\" Project, Banco do Brasil Foundation, WWF Brazil, ANA & FIPAI/EESC-USP. / A quantidade, a disponibilidade e, em particular, a qualidade da água doce está em degradação progressiva devido às mudanças ambientais no Antropoceno. Estratégias de adaptação baseadas em ecossistemas (EbA) são essenciais para reduzir estes impactos. Propõe-se um novo modelo de gerenciamento de recursos hídricos que integre a pegada hídrica cinza e processos ecohidrológicos para avaliação dos serviços hidrológicos em bacias hidrográficas sob mudanças. As etapas da pesquisa são: Capítulo 2 – análise dos projetos de pagamentos por serviços ambientais de proteção às bacias hidrográficas na Mata Atlântica brasileira e, no contexto de EbA, indicação de variáveis ecohidrológicas úteis na quantificação e futura valoração dos serviços hidrológicos; Capítulo 3 – desenvolvimento de plano de monitoramento ecohidrológico que integra aspectos qualitativos e quantitativos dos recursos hídricos para projetos de EbA; Capítulo 4 – provisão de dados experimentais de qualidade e quantidade da água, além de observações in-situ, para investigação das influências das mudanças de uso e ocupação do solo nas cabeceiras de mananciais, estratégicos para o abastecimento público e a conservação ambiental; Capítulo 5 – estimativas da pegada hídrica cinza para nitrato, fósforo total e sedimentos a partir do monitoramento de variáveis quali-quantitativas em bacias com diferentes condições de uso e ocupação de solo. Foi realizada a instalação de três Plataformas de Coleta de Dados, por meio de parceria entre EESC, ANA, CPRM, CEMADEN, SMA, TNC e WWF, visando aumentar a resiliência do sistema, decorrente de futuro aprimoramento da gestão, para a segurança hídrica. A metodologia incluiu coletas em seis diferentes períodos, durante dois anos, e análises das variáveis condutividade elétrica, cor, DQO, DBO5,20, nitrato, nitrito, nitrogênio amoniacal, fosfato, pH, turbidez, sólidos totais, coliformes termotolerantes, Escherichia coli, medidas de vazões e velocidades médias em seções transversais. O método foi aplicado em microbacias participantes dos projetos Produtor de Água/PCJ e Conservador das Águas, dentre outras, com áreas de drenagem entre 7 e 1.000 km2, que contribuem para a bacia do rio Piracicaba (12.530 km2). Dados primários, medidos em recente período de severa estiagem no Sistema Cantareira (2013-14), foram integrados aos bancos de dados de órgãos gestores federais e estaduais. A produção de água foi maior em sub-bacias menos florestadas. Foi possível aprimorar a regionalização de cargas poluidoras por área de drenagem na região do Cantareira. A pegada hídrica cinza (WF) foi estimada a partir de simulações no modelo ecohidrológico Soil and Water Assessment Tool (SWAT). Curvas de permanência de vazões e carga poluidora por área de drenagem foram elaboradas. Supondo-se a continuidade dos projetos \"Produtor de Água/PCJ\" e \"Conservador das Águas\", foram investigados os impactos de cenário futuro de uso do solo. Finalmente, foi desenvolvido novo índice ecohidrológico para quantificação dos serviços hidrológicos e avaliação a sustentabilidade das sub-bacias, a partir da pegada hídrica cinza composta. Assim, usando ferramentas de vanguarda tecnológica (SWAT e WF), a tese fornece subsídios para uma melhor compreensão dos impactos antropogênicos sobre os recursos hídricos e novas estratégias de adaptação baseada em ecossistemas, frente às progressivas taxas de perda de serviços ambientais. Esta tese esteve vinculada a três projetos de pesquisa, dos quais obteve apoio financeiro: (1) Projeto Temático FAPESP 2008/58161-1 \"Assessment of Impacts and Vulnerability to Climate Change in Brazil & Strategies for Adaptation Options\"; (2) \"INCLINE - INterdisciplinary CLimate INvEstigation Center\" (NapMC/USP) e (3) Projeto \"Água Brasil\", Fundação Banco do Brasil, WWF Brasil, ANA e FIPAI/EESC-USP.
19

Simulação numérica das interações biosfera-atmosfera em área de caatinga: uma análise da expansão agrícola em ambiente semiárido.

MELO, Ewerton Cleudson de Sousa. 14 August 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-14T10:58:52Z No. of bitstreams: 1 EWERTON CLEUDSON DE SOUSA MELO - TESE (PPGMet) 2016.pdf: 4714414 bytes, checksum: 399def91bcd71b3e8a00a6b001dcfd4b (MD5) / Made available in DSpace on 2018-08-14T10:58:52Z (GMT). No. of bitstreams: 1 EWERTON CLEUDSON DE SOUSA MELO - TESE (PPGMet) 2016.pdf: 4714414 bytes, checksum: 399def91bcd71b3e8a00a6b001dcfd4b (MD5) Previous issue date: 2011-06-30 / CNPq / Neste trabalho a versão 6.0 do modelo numérico RAMS (Regional Atmospheric Modeling System) é usada com o objetivo principal de simular a influência da expansão agrícola nas trocas de água e energia em áreas de Caatinga, e quantificar os efeitos das mudanças na cobertura e uso da terra na geração de circulações termicamente induzidas e na atividade convectiva. Os cenários de uso da terra investigados neste estudo foram construídos para representar condições ambientais nativas (sem influências antrópicas), e com alterações decorrentes da construção da represa de Sobradinho, e da expansão de atividades agrícolas e irrigação em região de clima semiárido. O ambiente atmosférico de grande escala é caracterizado pela estrutura dinâmica e termodinâmica típica da área central de um vórtice ciclônico de altos níveis (VCAN). A escolha do período de estudo teve como objetivo garantir condições ambientais com ampla diversidade agrícola em áreas de Caatinga (culturas de sequeiro e agricultura irrigada), e pouca nebulosidade. A evolução temporal da precipitação convectiva acumulada nas simulações da expansão agrícola mostra diferenças marcantes nos efeitos da agricultura de sequeiro e vegetação irrigada. O aumento na taxa da evapotranspiração nas áreas irrigadas eleva consideravelmente o teor de umidade nos baixos níveis da troposfera, reduz a temperatura do ar e diminui a precipitação convectiva. A descontinuidade na umidade e tipo de cobertura vegetal modifica a intensidade e distribuição dos fluxos turbulentos que são importantes na formação dos gradientes de pressão que geram circulações de brisa (brisa lacustre e de vegetação), de forma que o domínio nos transportes verticais de calor e água passa a ser da mesoescala. Verificou-se que as principais forçantes locais na determinação da distribuição espacial dos fluxos turbulentos e da chuva convectiva foram a topografia e a descontinuidade no teor de umidade do solo. Com relação a estabilidade atmosférica percebeu-se a existência de uma relação quase linear entre a Energia Potencial Convectiva Disponível (CAPE) e a temperatura potencial equivalente. / In this work the version 6.0 of the numerical model RAMS (Regional Atmospheric Modeling System) is used with the main objective of simulating the influence of agricultural expansion on the water and energy exchange in Caatinga vegetation areas, and to quantify the effects that changes on soil use and coverage have on the generation of thermally induced circulations and convective activity. The scenarios of soil use investigated are designed to represent native environmental conditions (without anthropogenic influences) and with alterations due to the implementation of the Sobradinho reservoir, and the expansion of agricultural activities and irrigation in a semiarid climate area. The large scale atmospheric ambient is characterized by the dynamic and thermodynamic structure typical of the central area of an upper level cyclonic vortex. The period of study was chosen aiming at environmental conditions with largely diversified agricultural use in Caatinga vegetation areas (agriculture with and without irrigation), and almost cloudless skies. The temporal evolution of the accumulated convective precipitation in the numerical simulations of the agricultural expansion shows large differences in the effects of agriculture with and without irrigation. The irrigated areas higher evapotranspiration rate causes a substantial increase in the moisture content in the lower troposphere, and lower the air temperature and convective precipitation.

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