• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 208
  • 135
  • 36
  • 9
  • 6
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 461
  • 461
  • 180
  • 174
  • 116
  • 115
  • 97
  • 91
  • 81
  • 55
  • 55
  • 43
  • 39
  • 38
  • 37
  • 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.
151

Evaluating the impact of institutional factors and stakeholder capabilities on performance of decentralized water resources management regimes in Mozambique : the case of Limpopo river basin

Matsinhe, Manuel Pedro 23 July 2012 (has links)
After the International Conference on Water and Environment in Dublin in 1992, the four socalled Dublin Principles created new managerial approaches for the water sector. This case study, which was conducted in the Limpopo Basin in Mozambique, examined the performance in the implementation of the principle related to “water development and management based on a participatory approach involving users, planners and policy makers at all levels”. The study was motivated by the fact that experience with the implementation of this principle in the Limpopo Basin of Mozambique has not delivered the anticipated outcomes. To this effect, this study analysed the history and performance of the decentralization process in the Limpopo Basin, and the factors that might have contributed to the outcomes we observe The methodology employed by the study was based on the framework for institutional analysis of decentralization reforms in natural resource management proposed by Dinar et al. (2005), Kemper et al. (2006), and Blomquist et al. (2008). This framework recommends that for the decentralization process to be successful, the following pre-requisites must be in place: (1) financial assistance from the state to enable basin level stakeholders to establish some of the organisations; (2) actors' participation and equitable representation of different segments of society, and acceptance of it from the communities; (3) the presence of basinlevel institutions, availability of forums for information sharing, communication and for conflict resolution; and (4) legitimacy, relevant human capacities and adequate financial resources among the River Basin Organizations (RBOs). The results from this study indicate that in as much as the Water Law, the Regulations of Water Services Provision and the Water Policy in Mozambique created the basis for the decentralization of water resources management, the operationalisation of the process has not been successful, considering that the prerequisites for an effective and sustainable decentralization process as postulated by Blomquist, Dinar and Kemper are still lacking. The study established that incentives for the decentralization process were not linked to the scarcity of water. The study further established that most prerequisites postulated by Blomquist, Dinar and Kemper were not satisfied, in particular: (1) the financial assistance from the state to enable basin level stakeholders to establish some of the organisations is inadequate; (2) the actors' participation and equitable representation of different segments of society with interest in water resources management is not satisfactory; and (3) the legitimacy, relevant human capacities and adequate financial resources for effective functioning of the Water Users Associations (WUAs) are still lacking. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2012. / Agricultural Economics, Extension and Rural Development / unrestricted
152

Sediment Dynamics of a Shallow Hypereutrophic lake: Lake Jesup, Florida, USA

Nielsen, Shauna 08 November 2011 (has links)
Improved knowledge of sediment dynamics within a lake system is important for understanding lake water quality. This research was focused on an assessment of the vertical sediment flux in Lake Jesup, a shallow (1.3 m average depth) hypereutrophic lake of central Florida. Sediment dynamics were assessed at varying time scales (daily to weekly) to understand the transport of sediments from external forces; wind, waves, precipitation and/or runoff. Four stations were selected within the lake on the basis of water depth and the thicknesses of unconsolidated (floc) and consolidated sediments. At each of these stations, a 10:1 (length to diameter) high aspect ratio trap (STHA) was deployed to collect particulate matter for a one to two week period. The water and sediment samples were collected and analyzed for total carbon (TC), total phosphorus (TP) and total nitrogen (TN). Mass accumulation rates (MAR) collected by the traps varied from 77 to 418 g m-2 d-1 over seven deployments. TN, TP and TC sediment concentrations collected by the traps were consistently higher than the sediments collected by coring the lake bottom and is most likely associated with water column biomass. A yearly nutrient budget was determined from August 2009 to August 2010 with flux calculated as 2,033,882 mt yr-1.
153

Desafios de gestão integrada de recursos naturais: a relação da gestão de recursos hídricos e a gestão territorial em bacias urbano-rurais - um estudo de caso na bacia hidrográfica do rio Itajai (SC) / DESAFIOS DA GESTÃO INTEGRADA DE RECURSOS NATURAIS: A RELAÇÃO ENTRE A GESTÃO DE RECURSOS HÍDRICOS E A GESTÃO DO TERRITÓRIO EM BACIAS URBANO-RURAIS: Um estudo de caso na Bacia Hidrográfica do Rio Itajaí (SC)

Sandra Irene Momm Schult 11 September 2006 (has links)
A gestão de recursos naturais é uma estratégia fundamental no enfrentamento dos problemas ambientais e na construção de uma condição de sustentabilidade. Esta gestão pode ser de caráter setorial e regulador, na medida em que não busca interferir no modelo de desenvolvimento, ou integrada, envolvendo ações compartilhadas em diferentes níveis com vistas a uma interação sócio-ambiental. No entanto, a implementação da gestão integrada reveste-se de igual complexidade aos problemas sobre os quais pretende atuar. Na discussão sobre a complexidade da implementação destacam-se dois aspectos interdependentes: a integração espacial entre diferentes escalas e territórios, e a integração institucional, considerando que nos últimos 25 anos existe uma sobreposição de ações não articuladas na arena ambiental. A partir deste modelo teórico analisa-se a articulação entre a gestão territorial no nível municipal e a gestão da água no nível da bacia hidrográfica com vistas à construção de uma gestão integrada. A abordagem conceitual é complementada com um estudo de caso na bacia hidrográfica do rio Itajaí (SC). Esta bacia, com ocupação urbanorural, abrange 50 municípios e possui uma população de aproximadamente 1.000.000 de habitantes. Como procedimento metodológico foram definidas 4 etapas que investigam a articulação na bacia hidrográfica do rio Itajaí. A primeira etapa trata da contextualização do objeto de estudo, ou seja, a caracterização da gestão da água e o papel do município. A segunda etapa caracteriza espacialmente agrupamentos de municípios que possuem características estruturais e dimensionais semelhantes, definindo uma tipologia. A terceira etapa metodológica estabelece relações entre os tipos definidos anteriormente, o uso do solo e a problemática da água nas sub-bacias. A quarta e última etapa, investiga, com base em uma pesquisa realizada nos municípios, as relações entre as escalas e os níveis de gestão. Do ponto de vista territorial a pesquisa demonstra que cerca de 70% do território da bacia encontra-se sob domínio de municípios rurais, em sua grande maioria em condição letárgica e esvaente. Em contraponto 40% da população da bacia reside nos dois centros urbanos atraentes. O resultado aponta que as dinâmicas de uso e ocupação do solo, cuja gestão é de competência municipal, não estão condicionadas à gestão de recursos hídricos. Por isto mesmo, as unidades de gestão de recursos hídricos não são suficientes para garantir o controle territorial e seus impactos na qualidade e quantidade de água. Entretanto, os pequenos e médios municípios muitas vezes não exercem o seu papel de gestor territorial, e a gestão de recursos hídricos, entendida aí em uma perspectiva da gestão integrada, pode representar novas possibilidades de articulação para a promoção da gestão do território municipal. / The management of natural resources is a basic strategy to face the environmental problems building the sustainable condition. This management can be described as sectorial and regulatory involving actions shared in different levels in the economic-environmental interaction with no inversion in the development model. However, the implementation of this integrated management is armed with equal complexity related to the problems on which it intends to act. In the subject on the complexity of the implementation two interdependent aspects are distinguished: the space integration between different scales and territories, and the institutional integration, considering that in last the 25 years exist an overlapping of the non-articulated actions in the environmental arena. With this theoretical model is analyzed the link between the territorial management in the district level and the water management in the level of the hydrographic basin looking to build an integrated management. The conceptual approach is complemented with the case study based on Itajaí River (SC) hydrographic basin. This basin with urban-agricultural occupation comprises 50 cities and approximately 1.000.000 of inhabitants. As methodological procedure 4 phases had been defined to investigate the link between territorial management and water management in the Itajaí River Basin. The first phase defines the context of the study object describing the water management and the function and actions the the district (duties and power of the districts). The second phase describes the groups of the cities with similar dimensions and structural characteristics defining a typology. The third methodological phase establishes relationship between the definite types (typology) defined previously, the use of the ground and the problematic related to the water management in the Itajaí (SC) river basin. The fourth and last phase, based on the research developed with all districts investigates the relationship between the scales and the management levels. In the territorial point of view the research demonstrates that about 70% of the river basin territory is under domain of the agricultural cities been the great majority in lethargic and diminishing conditions. In the other hand, 40% of the river basin population resides in the two attractive urban centers. The results show that the use and occupation of the land, which management is included in the district, is not conditioned to the water resources management. In fact, the units of management of water resources are not enough to guarantee the territorial control and its impacts in the quality and amount of water. However, many times small the medium districts can not execute their territorial management and water resources management with focus in the integrated management perspective promotes new possibilities for the district territorial management.
154

Hidrossolidariedade como princípio de gestão participativa de risco de inundações por associação de bacia / Hydrosolidarity as a principle of participative management of flood risk for basin association

Cristiane Aparecida Guedes Ribeiro 24 September 2007 (has links)
Ao longo do século XXI, a cultura de solidariedade dentro de uma bacia hidrográfica é baseada em aspectos legais. No caso brasileiro, isto é legitimado pela Constituição Federal de 1988, artigo 225, caput, \"Todos têm direito ao meio ambiente ecologicamente equilibrado, bem de uso comum do povo e essencial à sadia qualidade de vida, impondo-se ao Poder Público e à coletividade o dever de defendê-lo e preservá-lo para as presentes e futuras gerações\", e no artigo 3º que trata dos objetivos fundamentais da República Federativa do Brasil, entre eles, o inciso I que diz \"construir uma sociedade livre, justa e solidária\". Ainda neste contexto, o Código Civil Brasileiro, no artigo 265 menciona \"...a solidariedade não se presume; isto é, resulta da lei ou a vontade das partes...\". Também, visando uma gestão compartilhada, a Lei Federal 9.433/1997 cita no artigo 1º \"... a bacia hidrográfica é uma unidade territorial para políticas recursos hídricos... (V)\", e \"... a gestão dos recursos hídricos deve ser descentralizada e contar com a participação do Poder Público, dos usuários e das comunidades \"(VI). Desta forma, emerge o princípio de hidrossolidariedade destes contextos pré-mencionados nos cenários de discussão nacional e internacional. Esta pesquisa avaliou as limitações e os alcances do conceito de hidrossolidariedade, por meio da participação da comunidade nos problemas de drenagem urbana, com foco na gestão de risco de inundações. Embora a hidrossolidariedade seja um conceito pouco conhecido no Brasil, esta pesquisa estudou a viabilidade deste conceito com os atores sociais interessados em diferentes escalas espaciais da drenagem urbana: tanto na escala de lote domiciliar como na escala da bacia hidrográfica. A metodologia avaliou incentivos para os usuários da comunidade que aceitaram as ferramentas de hidrossolidariedade frente a problemas ambientais na gestão de inundações urbanas. Essas atitudes buscaram estimular a solidariedade e a responsabilidade cidadã na dimensão espaço-temporal. Em uma bacia estudada, os usuários participaram da criação de uma associação legalmente constituída por meio da metodologia explicada nesta pesquisa: \"Associação Amigos da Bacia do Tijuco Preto.\" Utilizou-se como ferramenta confirmatória entrevistas pessoais com usuários de duas bacias hidrográficas, Tijuco Preto e Gregório; analisaram-se dúvidas e realimentações de informações para propor e planejar a tomada de decisões no gerenciamento de recursos hídricos. Esta gestão foi caracterizada como participativa, compartilhada, integrada e continuada. Resultados da pesquisa apontaram que as partes possuem interesse e disponibilidade para desenvolver e compartilhar seu conhecimento sobre gestão de risco de inundação, bem como o espírito participativo e de solidariedade, para aplicação em sua comunidade com a finalidade de melhoria ambiental e bem estar do ser humano. / Throughout the XXI century, a culture of solidarity within a river basin is based on legal aspects. In Brazil, it is legitimated by the Federal Constitution of 1988, article 225, caput, \"Everybody is entitled to a ecologically-balanced environment, as well of common using by the people and essential to a healthy life quality, being imposed to the Public Power and the collective society the duty to defend it and to preserve it for the presents and future generations\". In the article 3 states about the fundamental objectives of the Federal Republic of Brazil, where in the item I says \"to build a free, just and solidarity society.\" Still in this context, the Brazilian Civil Code, in the article 265 mentions \"... the solidarity it is not presumed by itself; it is the result by law or by the willingness of the parties....\" Also, seeking a shared management, the Federal Law 9.433/1997 mention in the article 1 \"... the river basin is a territorial unit for water policies... (V)\", and \"... water resources should be decentralized and to count with the participation of the Public Power, of the users and of the communities\" (VI). Thus, the \"hydrosolidarity\" emerged from those fore-mentioned contexts at national and international arena. This research assessed the strengths and weaknesses of the concept of hydrosolidarity, thereby analyzing an application to urban drainage with community participation. Although hydrosolidarity is a concept not well known in Brazil, this research studied the feasibility of this concept with stakeholder and at different scales, either at the domiciliary lot or at the whole river basin scale. The methodology evaluated incentives for the community\'s users that accepted the tools of hydrosolidarity front to environmental problems in the management of urban floods. Those attitudes promoted stimuli toward citizenship solidarity and responsibility at spatiotemporal dimensions. Urban river basin users participated through the statements of the bylaws of a river basin association officially constituted through this research: the \"Association Friends of Tijuco Preto River Basin\". Through personal interviews to uses from two urban river basins, Tijuco Preto and Gregório, some doubts and feedbacks were surveyed in order to propose planning and decisionmaking on water management featured as participative, integrated and continuous. Results of the research depicted that social stakeholders had interests and willingness to develop and share their knowledge on flood risk management as well their participative solidarity to be applied into the community looking forward to achieving a higher environment and human well-being.
155

An analysis of heavy rainfall events over the Limpopo River Basin in southern Africa, their moisture sources and pathways

Rapolaki, Ramontsheng Sakia 29 October 2020 (has links)
Severe flooding events in subtropical southern Africa are not uncommon and can cause damage to infrastructure, lead to huge economic losses, and fatalities. Although extreme rainfall events can have far-reaching negative consequences, they can also provide large amounts of freshwater within a short time span, which supports the rain-fed farming upon which much of the population depends. However, the mechanisms through which extreme rainfall is produced in southern Africa are still not well understood. In particular, relatively little is known about where the moisture, a key ingredient in the rainfall, is sourced and how it is transported into the region. This thesis aims to address some of the gaps in this understanding by examining the moisture sources and subsequent moisture transport moisture into one of the key river basins in southern Africa, the Limpopo River Basin (LRB). The LRB, located in eastern southern Africa and spanning four countries, has experienced a number of extreme flooding events over the last three decades. Using CHIRPS satellite merged rainfall data for 1981-2016, the thesis identified the top 200 heavy extreme rainfall events in the LRB and the associated weather systems. It was found that tropicalextratropical cloud bands account for almost half of the events and tropical lows are responsible for just over a quarter. The remaining quarter of the events are associated with mesoscale convective systems and cut-off lows, the latter more important during transition seasons. Most of the events occur in the late summer when tropical lows and cloud bands are more common. Some relationships between the frequency of heavy rainfall events over the LRB and interannual climate modes of variability such as ENSO, SIOD, and SAM were found. Having examined the annual cycle of the top 200 heavy rainfall events, the analysis then applied the Lagrangian trajectory model HYSPLIT, with NCEP II reanalysis data as input, to backtrack air parcels from the LRB to their moisture source on seasonal scales and in terms of the types of weather systems involved. The resulting trajectories show that the seasonal transport of moisture over the LRB originates from seven moisture source regions; namely, local continental, tropical southeast Atlantic Ocean, midlatitude South Atlantic Ocean, tropical Northwest Indian Ocean, tropical southwest Indian Ocean, subtropical southwest Indian Ocean, and the Agulhas Current. Important differences in moisture source regions and pathways exist between early (OctoberDecember) and late (January-April) summers, with the tropical northwestern Indian Ocean and the northern Agulhas Current sources more prominent during JFMA than OND. Generally, moisture v source regions and transport pathways for LRB tend to be influenced by both the regional summer season circulation and the synoptic systems involved. Thus, it was found that cloud band and tropical low events within the top 200 tend to have the Congo Basin as an important moisture source whereas this source is less evident for cut-off low events. To help assess the robustness of the composite synoptic approach, the final part of the thesis applied the Lagrangian analysis to the most severe case in the top 200 events over the LRB (11- 21 January 2013). It was found that this case was largely linked to three main moisture sources: (1) tropical northwest Indian Ocean, (2) the Agulhas Current / Mozambique Channel, subtropical Southwest Indian Ocean, and (3) continental sources over the Congo Basin and northern Tanzania. Generally, the moisture source regions and pathways for the January 2013 event agreed with the climatological moisture source regions over the LRB, apart from the obvious absence of the tropical southeast Atlantic source in this case. In general, the thesis has provided a better understanding of the characteristics of heavy rainfall events over the LRB in terms of their associated weather systems, seasonality, interannual variability, and moisture source regions and trajectories.
156

People's Water and River Perceptions in the Selangor River Basin, Malaysia / マレーシア国セランゴール川流域における人々の水と川に対する意識に関する研究

Shimizu, Daigo 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22426号 / 工博第4687号 / 新制||工||1732(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 清水 芳久, 教授 田中 宏明, 教授 藤井 滋穂 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
157

DEVELOPMENT OF BIAS CORRECTION METHOD FOR GCM RUNOFF DATA AND ITS APPLICATION TO THE UPPER CHAO PHRAYA RIVER BASIN IN THAILAND / GCM流出発生量データに対するバイアス補正手法の開発とそのタイ国チャオプラヤ川上流域への適用

Teerawat, Ram-Indra 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23165号 / 工博第4809号 / 新制||工||1752(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 立川 康人, 准教授 市川 温, 教授 田中 茂信 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
158

Grave Matters: A Presentation and Comparative Analysis of the Late Classic Burials from Guajilar, Chiapas, Mexico

Wells, Shelley Lorraine 01 June 2015 (has links)
This thesis aims to identify the possible origins of the peoples who immigrated into the archaeological sites of Guajilar and Lagartero, located in the upper Grijalva River Basin region in southern Chiapas, Mexico, during the Late Classic period (AD 650-900). First, I present the Late Classic burial data from both sites according to four basic descriptive criteria: burial location, grave type, burial type, and grave goods. Then, I conduct a comparative analysis of the burial practices found at these two sites based on these criteria so that patterns in burial practices can be identified. Following the comparative analysis between Guajilar and Lagartero, I then compare their burial practices to those from two sites in the southern Maya Lowlands (Altar de Sacrificios and Seibal) and those found at various sites in the Guatemala Highlands (which border the upper Grijalva River Basin region to the north and east, respectively). The analysis reveals greater similarities in burial practices with sites in the Guatemala Highlands than with those in the southern Maya Lowlands. This suggests that peoples from the Guatemala Highlands were more likely to have immigrated into Guajilar and Lagartero during the Late Classic period.
159

Exposure and risk assessment of pharmaceuticals in challenging watersheds by enhanced geo-referenced modelling

Lämmchen, Volker 20 December 2021 (has links)
For this work the Geo-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER) was developed further to support river basin management and the implementation process within the EU Water Framework Directive (WFD). This was achieved through predicting spatially resolved pharmaceutical exposure concentrations in whole watersheds. A major focus of this thesis has been placed on modeling challenging watersheds, whereby challenging can refer to hydrological conditions in a watershed as well as to specific emission patterns that occur within the watersheds. The adapted methodology improves the prediction accuracy in such watersheds with GREAT-ER with respect to pharmaceutical exposures, but can also lead to improved results in other application areas. The possibilities of the latest model version are demonstrated by the extensive inclusion of local and regional conditions. In watersheds with highly variable and seasonally changing hydrological situations, GREAT-ER has been applied satisfactorily for the first time, and additionally, the developed approach can be transferred to equivalent watersheds worldwide. Comparison with monitoring data confirms that some of the adjustments have resulted in significantly improved model predictions, especially when hydrological and local conditions are specifically addressed. For example, explicit consideration of local drug emissions from hospitals or private medical practices (e.g., for x-ray contrast agents) can improve predictions at the local scale without compromising regional exposure estimates. Pharmaceuticals that have low concentrations and are barely detectable with established analytical methods can be evaluated with model simulations. In addition, current management strategies implemented under the WFD has been replicated and evaluated. These management scenarios simulated with the model allow an a priori evaluation of risk reduction measures. In combination with targeted monitoring approaches, it was shown that the GREAT-ER model can serve as a valuable tool for exposure and risk assessment of pharmaceuticals even in challenging watersheds. This and the useful combination of targeted monitoring and GREAT-ER simulations and the ability of the modeling approach to predict the expected range of spatial surface water concentrations is demonstrated by three selected journal articles.
160

Ranchers Adapting to Climate Variability in the Upper Colorado River Basin, Utah

Akbar, Hadia 01 May 2020 (has links)
Changes in climate influence agricultural production. This study looks at the impacts of climate variability in the Utah regions of the Upper Colorado River Basin by combining regression techniques with interview data to explore how climate variability affects agricultural production and how the farmers are adapting their practices to these changes. The results show that climate does not have any significant impact on cattle and hay production in the study area on a decadal scale. However, on an annual basis temperature seems to have more impact than precipitation. Among non-climatic variables, commodity prices and their regulations by the government are the most important factors that influence the year-to-year production. Farmers are well-aware of these impacts and have adapted significantly to the changes that occur on a year-to-year basis.

Page generated in 0.0525 seconds