2,557 research outputs found

    Estimating Potential Ground and Surface Water Pollution from Land Application of Poultry Litter - II

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    In Arkansas, approximately 1 Tg of poultry (Gallus gallus domesticus) manure and litter is produced annually. These waste products are commonly applied to pastures as a soil amendment or fertilizer, but excessive application rates and poor management practices could result in nutrient contamination of ground and surface water. The purpose of this study was to: (1) assess the nutrient concentrations in poultry manure and (2) evaluate the nitrogen loss from land-applied poultry litter and manure due to ammonia volatilization and denitrification. Analyses for total Kjeldahl nitrogen (TKN), inorganic nitrogen (Ni), phosphorus (P), and potassium (K) were compared in 12 wet and dry hen manure samples. Drying the manure reduced the TKN from 57 to 40 g N/kg on a dry weight basis in wet and dry manure, respectively. The Ni in the manure was in the ammoniacal form with values of 19 and 2 g N/kg for wet and dry manure, respectively. The P and K levels were not influenced by drying the manure and had values of 24 and 21 g/kg, respectively. The results indicate that the nitrogen content of hen manure can be significantly reduced by drying the sample prior to analysis. In a 10-day laboratory study and an 11-day field study to evaluate ammonia volatilization from surface-applied hen manure, results indicated that 37% of the total nitrogen content of the manure was lost. The results indicated that a substantial amount of nitrogen in surface-applied poultry waste can be lost due to ammonia volatilization. Laboratory studies to evaluate denitrification in a Captina silt loam amended with 9 Mg/ha of poultry litter were conducted. When the soil was aerobically incubated for 168 h and then flooded for 66 h, the nitrate-nitrogen level decreased a net of 17 mg N/kg. The results indicated that, if the ammoniacal nitrogen in the litter is oxidized to nitrate under aerobic conditions and then the soil is flooded and available carbon is present, denitrification can occur rapidly. Results from these studies indicate that soil and environmental conditions playa critical role in determining the potential for nitrate pollution of ground and surface water when poultry manure and litter are surface-applied to pastures

    Modelling and visualizing sustainability assessment in urban environments

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    Major urban development projects extend over prolonged timescales (up to 25 years in the case of major regeneration projects), involve a large number of stakeholders, and necessitate complex decision making. Comprehensive assessment of critical information will involve a number of domains, such as social, economic and environmental, and input from a wide a range of stakeholders. This makes rigorous and holistic decision making, with respect to sustainability, exceptionally difficult without access to appropriate decision support tools. Assessing and communicating the key aspects of sustainability and often conflicting information remains a major hurdle to be overcome if sustainable development is to be achieved. We investigate the use of an integrated simulation and visualization engine and will test if it is effective in: 1) presenting a physical representation of the urban environment, 2) modelling sustainability of the urban development using a subset of indicators, here the modelling and the visualization need to be integrated seamlessly in order to achieve real time updates of the sustainability models in the 3D urban representation, 3) conveying the sustainability information to a range of stakeholders making the assessment of sustainability more accessible. In this paper we explore the first two objectives. The prototype interactive simulation and visualization platform (S-City VT) integrates and communicates complex multivariate information to diverse stakeholder groups. This platform uses the latest 3D graphical rendering techniques to generate a realistic urban development and novel visualization techniques to present sustainability data that emerge from the underlying computational model. The underlying computational model consists of two parts: traditional multicriteria evaluation methods and indicator models that represent the temporal changes of indicators. These models are informed from collected data and/or existing literature. The platform is interactive and allows real time movements of buildings and/or material properties and the sustainability assessment is updated immediately. This allows relative comparisons of contrasting planning and urban layouts. Preliminary usability results show that the tool provides a realistic representation of a real development and is effective at conveying the sustainability assessment information to a range of stakeholders. S-City VT is a novel tool for calculating and communicating sustainability assessment. It therefore begins to open up the decision making process to more stakeholders, reducing the reliance on expert decision makers

    Enhancing urban sustainability through novel visualisation

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    Sustainable decision making in Urban Design is a complex and non-linear process that requires the interaction of a wide variety of stakeholders. The engagement of a range of stakeholders throughout the decision making process presents challenges including the need to communicate the complex and interdependent facets of sustainability and the need to demonstrate the short and long term implications of alternative courses of action.This paper presents the results of an initial application of a prototype simulation and visualisation tool (S-City VT) that was developed to enable all stakeholders, regardless of background or experience, to understand, interact with and influence decisions made on the sustainability of urban design. S-City VT takes the unique approach of combining computer game technology with computer modelling to present stakeholders with an interactive virtual development. The paper uses the Dundee Central Waterfront Development Project as a case study to evaluate the potential for the application of the tool and explains how parallel research work on the implementation of a sustainability enhancement framework for the Central Waterfront Development has informed the choice of sustainability indictors and identified the key stakeholders in the decision making processes.The paper shows how stakeholders can be presented with the outputs from the model using a 3D visualisation of the development and thus enables judgements to be made on the relative sustainability of aspects of the development. The visualisation tool employs a number of different methods of displaying the sustainability results to the stakeholders. These methods can show data in varying levels of complexity, depending on the expertise of the stakeholder, empowering all stakeholders by illustrating possible interactions between indicator values and sustainability and by showing how different stakeholder perceptions of the importance of the indicators can influence the sustainability assessment.Initial tests on the effectiveness of the different visualisation methods in displaying the model output to communicate the sustainability of the Development are described. The results of the tests and presented and discussed and conclusions are drawn on the further development and application of the tool to model and visualise through time the possible results of decisions made at different stages of the project

    Immersive and non immersive 3D virtual city: decision support tool for urban sustainability

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    Sustainable urban planning decisions must not only consider the physical structure of the urban development but the economic, social and environmental factors. Due to the prolonged times scales of major urban development projects the current and future impacts of any decision made must be fully understood. Many key project decisions are made early in the decision making process with decision makers later seeking agreement for proposals once the key decisions have already been made, leaving many stakeholders, especially the general public, feeling marginalised by the process. Many decision support tools have been developed to aid in the decision making process, however many of these are expert orientated, fail to fully address spatial and temporal issues and do not reflect the interconnectivity of the separate domains and their indicators. This paper outlines a platform that combines computer game techniques, modelling of economic, social and environmental indicators to provide an interface that presents a 3D interactive virtual city with sustainability information overlain. Creating a virtual 3D urban area using the latest video game techniques ensures: real-time rendering of the 3D graphics; exploitation of novel techniques of how complex multivariate data is presented to the user; immersion in the 3D urban development, via first person navigation, exploration and manipulation of the environment with consequences updated in real-time. The use of visualisation techniques begins to remove sustainability assessment’s reliance on the existing expert systems which are largely inaccessible to many of the stakeholder groups, especially the general public

    Enhancing urban sustainability using 3D visualisation

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    This paper presents the results of an initial application of a prototype simulation and visualisation tool (S-City VT) thatwas developed to enable all stakeholders, regardless of background or experience, to understand, interact with and influence decisions made on the sustainability of urban design. The tool takes the unique approach of combining three-dimensional (3D) interactive and immersive technologies with computer modelling to present stakeholders with an interactive virtual development. Use of outputs from the model and a 3D visualisation of the development can help decision-makers judge the relative sustainability of different aspects of a development. The tool employs a number of different methods to present sustainability results to stakeholders. Initial tests on the effectiveness of the different visualisation methods are described and discussed. The paper then presents some conclusions on further development and application of the tool to model and visualise possible results of decisions made at different stages of the project

    Sustainable urban development in practice:the SAVE concept

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    The need for sustainable development of the urban environment presents the research community with a number of challenges and opportunities. A considerable volume of research has been undertaken into the constituent parts of this complex problem and a number of tool kits and methodologies have been developed to enable and encourage the application of specific aspects of research in practice. However, there is limited evidence of the holistic integration of the body of knowledge arising from the research within real-life decision-making practices. In this paper we present an overview of the existing body of knowledge relating to sustainable development of the urban environment and propose a generic framework for its integration within current practices. This framework recognises the need to: understand social, economic, and environmental issues; understand the decision-making processes; provide a means of measurement, assessment, or valuation of the issues; provide analytical methods for the comparative assessment of complex data to enable an evaluation of strategies and design options and to communicate effectively throughout the process with a wide range of stakeholders. The components of a novel sustainability assessment, visualisation and enhancement (SAVE) framework, developed by the authors to ‘operationalise’ the body of knowledge are presented and justified. These include: decision-mapping methods to identify points of intervention; indicator identification and measurement approaches; appropriate mathematical and analytical tools and an interactive simulation and visualisation platform which integrates and communicates complex multivariate information to diverse stakeholder groups. We report on the application of the SAVE framework to a major urban development project and reflect on its current and potential impact on the development. Conclusions are also drawn about its general applicability
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