• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 304
  • 108
  • 46
  • 42
  • 41
  • 21
  • 9
  • 5
  • 5
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • Tagged with
  • 716
  • 716
  • 114
  • 98
  • 87
  • 79
  • 69
  • 59
  • 56
  • 55
  • 55
  • 53
  • 52
  • 51
  • 51
  • 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.
241

Temporal changes in runoff and erosion processes on disturbed landscapes under natural rainfall

Carroll, C. K. Unknown Date (has links)
No description available.
242

Development of indicators for assessing and monitoring nutrient influences in coastal waters

Costanzo, S. D. Unknown Date (has links)
No description available.
243

Development of indicators for assessing and monitoring nutrient influences in coastal waters

Costanzo, S. D. Unknown Date (has links)
No description available.
244

Toward a Conceptual Framework for a more Sustainable Water Ethic: Identifying the Ethical Underpinnings of Water Management

Justine Lacey Unknown Date (has links)
Water management has been described as one of the major natural resource management challenges facing our rural industries, regional communities, our unique natural environments and indeed, even our survival. Within this context, water ethics has emerged as a research area of some significance. However to date, a majority of the research has clustered around economic and environmental concerns. For the most part, explorations into the ethical management of water have been limited to a deliberative focus on the establishment of property rights and effective water pricing and trading mechanisms. These narrow economic approaches fail to recognise the diversity and plurality of our water values or to adequately address broader social values such as equity and justice. This research aims to address these imbalances by focusing on how we might develop a deeper understanding of ethical practice in the context of more sustainable water management. It achieves this by outlining an alternative ethical framework which will support these more sustainable social and policy outcomes. Thus, the rationale for this thesis is to demonstrate that contractual ethics, or even more specifically Scanlonian contractualism, is a viable alternative normative ethical framework to utilitarianism for considering how we might justify these more sustainable water management outcomes. There is significant debate and conflict over how water should best be managed. These debates capture not only the nature of the way we interact with the environment but also the way we interact with each other. It is in these two sets of interactions that ethics can provide us with a way of justifying our actions and decisions and a basis for determining what we consider to be right or wrong, or acceptable or unacceptable in terms of water management practice. An important element of this thesis is recognising that how we think about water has important implications for how we manage water and to date, this has been undervalued in water management. To that end, I argue we must necessarily begin to appreciate the connection between what is happening in our conceptual and theoretical landscapes and how this impacts on our physical landscapes. It is in these interactions and connections that we begin to appreciate both the depth of complexity and the ‘wicked’ nature of water management. Thus, each of these debates and their related concerns exists within the broader context of how we think water should be managed and the processes by which we come to make and justify our decisions about water management. This thesis is therefore aimed at addressing this gap in the research around ethical water management. It achieves this by providing the basis for a framework which can capture not only the philosophical and ethical underpinnings of a more sustainable water ethic but also recognise and accommodate the significant research already undertaken in a variety of other disciplines. As a result, this thesis is necessarily interdisciplinary in its approach. While I base my arguments in the field of philosophical and ethical inquiry, the construction of a conceptual framework for a more sustainable water ethic is applicable to and widely influenced by a number of other fields including geography, anthropology, scientific research, economic theory, public policy and social theory. In recognising and preserving the interdisciplinary knowledge base around water management, part of the challenge has been to construct a conceptual framework and define ethical principles that can both honour this interdisciplinarity but also remain relevant in cross disciplinary settings. The nature of this interdisciplinary approach reinforces the inherent complexity of water management and was cause for some reflection because it raised the question of how best to address the research problem. This process of reflection had direct implications on the research process adopted in this thesis because it required not only an interdisciplinary response but also a balanced approach to preserving the complexity and the ‘wickedness’ of water management. These elements needed to be preserved in the research process because they are integral to our understanding of water management and inevitably raise the difficult and particularly ‘human’ questions we associate with it. Thus, the research process adopted in this thesis can be best understood as a process of reflective equilibrium. Reflective equilibrium describes the process by which we systematically examine our judgements and beliefs about a certain issue, searching for coherence with other beliefs and then revising those beliefs where evidence suggests they need to be modified. This approach allows for a range of diverse disciplinary considerations and interests to be considered in a holistic manner and is reflected in the following research activities. In the course of this thesis, I outline the development and construction of a conceptual framework for a more sustainable water ethic, which is based on a diverse range of disciplinary knowledge and expertise. This framework is supported by a rigorous and systematic application of contractual ethical principles. The first part of the thesis reflects a process of examination and review of relevant theoretical and methodological concerns, which enable interdisciplinary research to occur. In the second part of this thesis, a detailed analysis of contractual ethical principles and a philosophical analysis of values in the context of water management are presented. The findings elicited from these stages of the research are taken forward and used to examine two deliberately chosen but quite distinct case study analyses. These two case study examples reflect the diversity and range of political and policy concerns within the broader water management debate.
245

Sustainable urban water systems : policy and professional praxis

mike.mouritz@dpi.wa.gov.au, Mike Mouritz January 1996 (has links)
The provision of water, wastewater and stormwater infrastructure is an essential ingredient of cities. However, questions are being raised about the type and form of urban infrastructure, for economic and environmental reasons. Traditionally these techologies have offered linear solutions, drawing increasing volumes of water into cities and discharging waste at ever increasing levels, causing escalating stress on the environment. In addition the costs of water infrastructure provision and replacement, both in the developing and developed world, is becoming prohibitive. In response, a new paradigm has been called for and new solutions are emerging that have been labelled as Integrated Urban Water Management (IUWM). This concept can be considered to consist of both technical and philosophical dimensions, and represents a new form of professional praxis. However, the adoption of these techniques and concepts is constrained by the inertia of the existing urban water systems. It is therefore argued that the introduction of any change must occur across a number of dimensions of the technoeconomic system of the city. These dimensions-artefacts and technical systems (i.e. the technology and knowledge systems), professional praxis and socio-political context (i.e. institutions, culture and politics) and biophysical realities and world views (i.e. the environment and underlying values) - provide a framework for analysis of the change process - both how it is occurring and how it needs to occur. This framework is used to illustrate the link between environment values and the process of technological innovation, and points to the need for the emerging values and innovations to be institutionalised into the professional praxis and socio-political context of society. Specifically, it is argued that a new form of transdisciplinary professional praxis is emerging and needs to be cultivated. A broad review of the literature, an evaluation of selected emerging technologies and three case studies are used to illustrate and argue this position. These examples show the potential economic, social and environmental benefits of IUWM and provide some insight into the potential which this approach has to influence the form and structure of the city and at the same time highlighting the institutional arrangements required to manage urban water systems.
246

Land use, freshwater flows and ecosystem services in an era of global change /

Gordon, Line, January 2003 (has links)
Diss. (sammanfattning) Stockholm : Univ., 2003. / Härtill 5 uppsatser.
247

I djupet av ett vattendrag : om konflikt och samverkan vid naturresurshantering = In the depth of a watershed : on conflict and collaboration in natural resource management /

Hallgren, Lars, January 2003 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003.
248

Multi-century records of snow water equivalent and streamflow drought from energy-limited tree rings in south coastal British Columbia

Coulthard, Bethany L. 04 January 2016 (has links)
Anthropogenic climate change has triggered widespread shifts in the global hydrological cycle. In south coastal British Columbia, these changes have led to more winter precipitation falling as rain rather than snow, more rain on snow events, and generally reduced snowpacks. Since snowmelt is a primary source of summer surface runoff and groundwater, snowpack declines have caused severe seasonal streamflow droughts in recent decades. For accurate water supply forecasting under future climate change, it is crucial to know if snowpack and runoff declines are unprecedented in the last several hundred years. This research focused on developing multi-century, annually-resolved records of snow water equivalent and streamflow drought to determine if recent conditions deviate from long-term norms. The research targeted small temperate watersheds that are not usually conducive to application of dendrohydrological methodologies. Traditional dendrohydrology relies on moisture-limited tree-ring records from arid settings. This dissertation presents a new method for developing tree-ring based reconstructions from energy-limited trees. Tree-ring records from high-elevation mountain hemlock (Tsuga mertensiana (Bong.) Carrière) and amabilis fir (Amabilis (Dougl.) Forbes) stands were collected at sites in south coastal British Columbia. Ring-width measurements were used to develop multi-century dendrohydrological models of snow water equivalent and streamflow drought. A 322-year reconstruction of May 1 snow water equivalent for Vancouver Island explains 56% of the instrumental SWE data variance and suggests snowpacks in 2015 were lower than in any year since 1675. A 477-year reconstruction of summer streamflow for Tsable River explains 63% of gauged streamflow variance and indicates that since 1520 twenty-one droughts occurred that were more extreme than recent “severe” droughts. Finally, a reconstruction of regionally synchronous streamflow among four south coastal rivers explains 64% of the regionalized streamflow variance. In addition to snow-sensitive tree-ring data, the latter model incorporated a paleorecord of the Palmer Drought Severity Index as a summer temperature and aridity proxy. The reconstruction suggests that since the mid-1600s sixteen regional-scale droughts occurred that were more extreme than any within the instrumental period. All three models were particularly accurate at estimating lowest snow and runoff years, and reflected the long-term influence of cool phases of the Pacific Decadal Oscillation on regional snowmelt and summer discharge trends and patterns. The reconstructions suggest: 1) snowpack declines in 2015 were unmatched in the past ~340 years; and, 2) existing water management strategies based on hydrometric data records underestimate potential magnitudes of natural droughts. Worst-case scenario droughts compounded by land use change and climate change could result in droughts more severe than any in the past several hundred years. Energy-limited tree-ring records have strong potential as paleohydrological proxies and for expanding applications of dendrohydrology to arid settings. For some of the tree-ring chronologies examined in this study, the correlation with snow water equivalent became non-significant after the mid-1990s, possibly due to warming spring temperatures. Future studies using this type of tree-ring data must carefully evaluate the recent stability of climate-growth relationships. / Graduate / 0368 / 0388 / coulthard.bethany@gmail.com
249

Inclusive public spaces for water management in rural India / A design framework of the public spaces associated with water infrastructure in rural India to promote sustainable water management

Wong, Tsz Wai January 1900 (has links)
Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Alpa Nawre / Stephanie A. Rolley / In underprivileged communities in developing countries, water is essential for basic survival. Particularly for rural communities, water supports irrigation for agriculture and, hence, the livelihood of villagers. Based on a forecast by the Asian Development Bank, India is expected to reach a water deficit of 50% by 2030 (Dutta, 2017). Without awareness of conservation and efforts to conserve water resources and protect them from being polluted by industries and communities, rural Indian communities will continue to suffer from water mismanagement and the loss of potential long-term environmental, social, and economic benefits that water can bring to a community. Nonetheless, better water management is attainable in rural communities. Given the model Indian villages that have been transformed into sustainable communities by implementing and managing effective blue-green infrastructure through community participation, landscape architects are proven that they are capable of various roles in leading, initiating, and providing design and technical support for water infrastructure projects of different scales in rural India. Since stewardship and maintenance of these systems are critical for long-term effectiveness, the core idea of this design project is leveraging local efforts and community power to build and maintain functional water infrastructure as a better, more sustainable water management strategy. In this study, public space associated with water infrastructure is considered as a potential driver for local efforts to maintain the water management landscape when those public spaces are designed for inclusiveness and diversity. Thus, the project goal is to create or transform the public space associated with existing water infrastructure into an inclusive, productive community place that can generate environmental, social, and economic benefits, as a strategy for sustainable water management in rural India. Currently, the proposed water management landscape in this study is a diverse public space shared by community members of different ages, genders, classes, castes, and religions. The research methodology divides into three phases. The first phase addresses the general water issues and the cultural background of rural India through literature and preliminary site inventory using the GIS data provided by the Panchayat of Dhamori. The second phase presents the perceptions of villagers in Dhamori about using water and public space after collecting quantitative and qualitative data through site observation and participatory planning. By synthesizing and analyzing the knowledge generated from the participatory process on-site, the final phase interprets and addresses the emergent problems through developing a design framework for conceptual site design.
250

Demandas e disponibilidades hídricas da bacia hidrográfica do rio Pardo (RS) nos cenários atual e futuro para diferentes sistemas de produção de arroz irrigado

Helfer, Fernanda January 2006 (has links)
A Bacia Hidrográfica do Rio Pardo é uma das 9 (nove) bacias que integram a Região Hidrográfica do Guaíba, no Rio Grande do Sul, sendo sua área de drenagem de aproximadamente 3.636 km². Os rios Pardo e Pardinho são os principais cursos de água, com extensões de aproximadamente 200 e 90 km, respectivamente. Estudos realizados recentemente sobre a situação atual dos recursos hídricos da Bacia do Rio Pardo constataram a ocorrência de deficiências hídricas em determinados períodos do ano e em algumas regiões. Estas deficiências foram atribuídas, principalmente, à demanda de água pela orizicultura, que representa 87% do volume total requerido anualmente e 97% do volume total requerido em janeiro, mês de maior demanda de água na Bacia. Dentro deste contexto, esta dissertação teve como objetivo geral analisar, sob as perspectivas da orizicultura irrigada, a situação hídrica quantitativa da Bacia Hidrográfica do Rio Pardo no cenário atual e em cenários futuros. Buscou-se quantificar os déficits hídricos (quando existentes) e identificar os cenários menos impactantes para os usuários da água da Bacia. Um modelo para estimativa da disponibilidade hídrica da Bacia foi testado e analisado. No entanto, quando da realização dos balanços hídricos, preferiu-se utilizar vazões observadas e medidas nos principais rios da Bacia, adotando-se, como disponibilidade hídrica, as vazões com 90% de garantia de excedência. Foram estabelecidos dois cenários futuros para a orizicultura – Tendencial e Otimista – os quais foram analisados sob duas projeções (4 e 12 anos). Os cenários foram configurados com base na combinação entre diferentes sistemas de cultivo e ciclo das cultivares de arroz, que, juntos, determinam diferentes demandas específicas, e, conseqüentemente, diferentes volumes totais por cenário. A demanda hídrica de cada cenário foi estimada utilizando-se um modelo matemático integrado a ferramentas de geoprocessamento. O modelo considera os principais componentes da demanda hídrica para irrigação (evapotranspiração, saturação do solo, lâmina superficial e fluxo lateral). Os resultados indicaram uma tendência de melhoria na eficiência de uso da água para irrigação na Bacia, com aumento de área cultivada e diminuição da demanda hídrica por unidade de área. Esse quadro pode ser atribuído, principalmente, ao aumento de lavouras sistematizadas, que garantem menor demanda hídrica, devido ao melhor aproveitamento da água de irrigação. A melhoria na eficiência de utilização da água é ainda maior nos cenários otimistas, em que se pressupõe, além do aumento de áreas sistematizadas, a utilização de cultivares de ciclo menor, condicionando reduções no período de irrigação. Apesar disso, os balanços hídricos realizados para cada cenário indicam a ocorrência de déficits hídricos mais graves do que os atuais nos cenários futuros. Esta configuração é atribuída ao aumento da área cultivada, que, mesmo com demanda específica menor, não garante que os conflitos sejam minimizados. Mesmo assim, os resultados mostraram que, dentro de uma mesma projeção futura, existe a possibilidade de haver significativas reduções na utilização de água, o que é evidenciado através das diferenças constatadas na comparação dos cenários tendenciais e otimistas, sendo estes últimos, menos impactantes na disponibilidade hídrica. A gestão e o planejamento de recursos hídricos, neste contexto, permitem disciplinar o uso e alocar a água entre os diversos usuários de uma bacia hidrográfica através da implementação de instrumentos de gestão e planejamento, como a outorga e a cobrança; no entanto, subsídios como os apresentados neste trabalho são necessários, pois, para que haja efetividade na implementação dos instrumentos, é fundamental que se conheçam as distribuições espacial e temporal das disponibilidades e demandas hídricas de cada Bacia Hidrográfica, e que se considerem as tecnologias empregadas nos diferentes sistemas de produção, que têm a água como insumo básico. / The Pardo River Basin (3.636 km²) is one of the 9 (nine) basins integrating the Guaíba Watershed Region, in the state of Rio Grande do Sul, Brazil. Pardo and Pardinho rivers are the most important water courses, with extensions of about 200 and 90 km, respectively. Recent studies about current water availability and water demand in Pardo River Basin showed the occurrence of water deficiencies in some periods of the year and in some areas. These deficiencies were attributed, mainly, to demand to rice irrigation that represents 84% of total volume requested annually, and 97% of total volume requested in January, month of higher water demand in the Basin. This study had as main objective to analyze, under the perspectives of the irrigated rice crop, the quantitative water situation in Rio Pardo River Basin in current and futures sceneries. It looked for quantifying water deficits (when existent) and to identify the less impactant sceneries to the Basin water users. A model to estimate water availability was tested and analyzed. However, to water balances, it was preferred using observed discharge measured in the principal rivers of the Basin, adopting, as water availability, the discharge with 90% of chance to exceeding. Two future sceneries were established related to rice system crop – Tendencial and Optimist – that were analyzed under two projections (4 and 12 years). The sceneries were configured based on combination of cultivation systems (soil manage) and rice variety cycle, that, together, determines different specific demands, and, consequently, different total volumes for each scenery. The water demand in each scenario was calculated using a mathematical model integrated to geoprocessing tools. The model considers the main components of irrigation demand to rice crop (evapotranspiration, soil saturation, superficial depth and lateral flow). Results indicated a tendency to improve efficiency of water use in rice irrigation, with increase of cultivated area and decrease in specific water demand. This frame can be attributed, mainly, to increasing of systematized crop soil that assures smaller water demand, due to the best use of water irrigation. The improvement in water use efficiency is larger in optimistic sceneries, when it’s presupposed, in addition to increase of systematized areas, the use of rice variety with smaller cycle, conditioning reductions in irrigation period. In spite of that, the water balances to the futures sceneries indicate the occurrence of worse water deficits than in the current one. This configuration is attributed to increasing in cultivated area that, even with smaller specific water demand, does not assure that conflicts are minimized. Even so, the results showed that there are possible reducing water use into a same future projection, evidenced through differences verified in the comparison between tendencial and optimists sceneries, when these last, are less impactant in the water availability. The water resources management, in this context, allow disciplining water use and to allocate it among several existent users through planning instruments implementation, as the grant and collection; however, subsidies as showed in this work, are essential to implement these instruments. Is fundamental that spatial and temporary distribution of water availability and water demand are known, and that technologies employed in different production systems using water like a basic input be considered.

Page generated in 0.0773 seconds