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Systematic Simplification Of Mechanistic Models, Neil Crout, Glen Cox, James Gibbons Jul 2006

Systematic Simplification Of Mechanistic Models, Neil Crout, Glen Cox, James Gibbons

International Congress on Environmental Modelling and Software

Models of environmental systems are often complex, reflecting the complexity of the systems they try and describe. This complexity is difficult to manage and, especially in the face of limited observed data, there is a risk that models become over-parameterised with the result that predictions are less reliable than they need be. An approach to investigating the influence of model complexity on prediction accuracy is to compare the performance of alternative (simpler) model formulations. However this is difficult to achieve in practice as the process of simplification can be time-consuming with the consequence that only a few alternative formulations can …

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Rank-Equivalence Method For Sensitivity Analysis Of An Integrated Model Of A River Catchment, J. K. Ravalico, Graeme C. Dandy, Holger R. Maier Jul 2006

Rank-Equivalence Method For Sensitivity Analysis Of An Integrated Model Of A River Catchment, J. K. Ravalico, Graeme C. Dandy, Holger R. Maier

International Congress on Environmental Modelling and Software

Integrated Assessment Modelling (IAM) incorporates knowledge from different disciplines to provide an overarching assessment of the impact of different management decisions. Integrated models generally require numerous parameters from varying sources, many not known with certainty. Rapid increases in model size and complexity, particularly in the case of integrated models for decision-making, pose new challenges for effective sensitivity analysis. Some of the identified shortcomings of existing sensitivity analysis methods in the context of IAM include: computational inefficiency, failure to assess parameter interactions, excessive data requirements (e.g. requiring parameter probability distributions), assumptions of model linearity and monotonicity and, in particular, difficulty of …

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Modelling Of Water Pollution In Urban Areas With Gis And Multivariate Statistical Methods, L. Matejicek Jul 2006

Modelling Of Water Pollution In Urban Areas With Gis And Multivariate Statistical Methods, L. Matejicek

International Congress on Environmental Modelling and Software

Integrating modelling of water pollution and GIS enables the connection of environmental process models with geospatial data describing the physical environment. Time series of water pollution data at monitoring profiles are used to complement the spatial database and to interpret the results of data analysis. In this case, the multivariate statistical methods provide an exploratory environment for data analysis and an indication of seasonal changes in the framework of surface water pollution. In addition to a wide range of useful multivariate methods, principal component analysis (PCA) and factor analysis (FA) are used to differentiate seasonal water pollution at monitoring profiles. …

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Experiences On Empirical Assessment Of Rule-Based Ai Systems For Ecological Modelling, V. Brilhante Jul 2006

Experiences On Empirical Assessment Of Rule-Based Ai Systems For Ecological Modelling, V. Brilhante

International Congress on Environmental Modelling and Software

In working with Artificial Intelligence (AI) techniques,more specifically logic-based knowledgerepresentation and reasoning, applied to environmentalmodelling, again more specifically, to automatingaspects of construction of ecological simulationmodels of the system dynamics kind, I havehad a couple of opportunities to work on projectswhere comparative empirical assessments of systemswere performed. More and more, the degree ofcomplexity of AI systems renders them unsuitablefor purely theoretical analytical studies, compellingus to resort to empirical methods which throughdata can flesh out the workings of a system and helpus understand its behaviour and results.

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Experience Gained From The Use Of Environmental Information Systems For The Public In The State Of Baden-Wuerttemberg, Werner Geiger, C. Düpmeier, M. Ruchter, T. Schlachter, R. Ebel, M. Linnenbach Jul 2006

Experience Gained From The Use Of Environmental Information Systems For The Public In The State Of Baden-Wuerttemberg, Werner Geiger, C. Düpmeier, M. Ruchter, T. Schlachter, R. Ebel, M. Linnenbach

International Congress on Environmental Modelling and Software

For the protection of the natural environment and a sustainable development, joint responsibility and participation of the citizens are indispensable. In this connection, enlightenment and information of the public and the promotion of environmental awareness play a crucial role. This contribution shall present various environmental information systems for the public and report about the experience gained from their development and operation. The systems have been developed as parts of the Baden-Wuerttemberg Environmental Information System by Forschungszentrum Karlsruhe in cooperation with the State Institute for the Environment, Measurements, and Nature Protection. In particular, the Baden-Wuerttemberg Environmental Information Network with a portal …

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Uncertainty Management, Spatial And Temporal Reasoning, And Validation Of Intelligent Environmental Decision Support Systems, Miquel Sànchez-Marrè, Karina Gibert, Rick Sojda, Jean-Philippe Steyer, Peter Struss, Ignasi Rodríguez-Roda Jul 2006

Uncertainty Management, Spatial And Temporal Reasoning, And Validation Of Intelligent Environmental Decision Support Systems, Miquel Sànchez-Marrè, Karina Gibert, Rick Sojda, Jean-Philippe Steyer, Peter Struss, Ignasi Rodríguez-Roda

International Congress on Environmental Modelling and Software

There are inherent open problems arising when developing and running Intelligent Environmental Decision Support Systems (IEDSS). During daily operation of IEDSS several open challenge problems appear. The uncertainty of data being processed is intrinsic to the environmental system, which is being monitored by several on-line sensors and off-line data. Thus, anomalous data values at data gathering level or even uncertain reasoning process at later levels such as in diagnosis or decision support or planning can lead the environmental process to unsafe critical operation states. At diagnosis level or even at decision support level or planning level, spatial reasoning or temporal …

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New Directions And Challenges In Spatial Dynamic Modelling Of Ecosystem Functions In Heterogeneous Landscapes As Basis For A Better Sustainable Landscape Management, Karl-Otto Wenkel, Ralf Wieland, Wilfried Mirschel Jul 2006

New Directions And Challenges In Spatial Dynamic Modelling Of Ecosystem Functions In Heterogeneous Landscapes As Basis For A Better Sustainable Landscape Management, Karl-Otto Wenkel, Ralf Wieland, Wilfried Mirschel

International Congress on Environmental Modelling and Software

The aim of this paper is to discuss scientific challenges and new possibilities for a better modelling of consequences of land use changes in heterogeneous landscapes on ecosystem functions in space and time. The landscape or regional scale means an area of about 100 km2 up to some 1000 km2. Main problems on this scale are high complexity, structural diversity, ecological heterogeneity and uncertainty in data, in understanding of the process dynamic and by uncertainty in models.

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Avoiding The Finite Difference Sensitivity Analysis Deathtrap By Using The Complex-Step Derivative Approximation Technique, Dirk J. W. De Pauw, Peter A. Vanrolleghem Jul 2006

Avoiding The Finite Difference Sensitivity Analysis Deathtrap By Using The Complex-Step Derivative Approximation Technique, Dirk J. W. De Pauw, Peter A. Vanrolleghem

International Congress on Environmental Modelling and Software

In this paper, the complex-step derivative approximation technique will be used for calculating local sensitivity functions. This technique is compared to the finite difference approximation, probably the most used local sensitivity analysis technique. For this comparison, 4 biotechnological models with varying model complexity were used. A well known problem of the finite difference approximation is the choice of a suitable perturbation factor in order to avoid non-linear model effects or numerical errors due to the subtraction of almost equal numbers. The main advantage of the complex-step derivative approximation technique is that it is not susceptible to errors introduced by small …

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Building A Community Modeling And Information Sharing Culture, Alexey Voinov, Raleigh R. Hood, John D. Daues Jul 2006

Building A Community Modeling And Information Sharing Culture, Alexey Voinov, Raleigh R. Hood, John D. Daues

International Congress on Environmental Modelling and Software

By copying information from sources and distributing it to new destinations we do not loseinformation at the sources. Nevertheless, exchange of information is still restricted by patent law, as well asby institutional, cultural and traditional hurdles that create protective barriers hindering the free flow of thisvaluable commodity. We believe that one of the greatest challenges we face in creating a new researchparadigm will be building the community modeling and information sharing culture. How do we getengineers and scientists to put aside their traditional modes of doing business? How do we provide theincentives that will be required to make these changes …

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Decision Support System For The Assessment And Evaluation Of Ecological Impacts On Aquatic Ecosystems: Objectives And Framework, Paola Agostini, Elena Semenzin, A. Critto, Christian Micheletti, Paulo Nunes, Andrea Ghermandi, Stefania Gottardo, S. Giove, Dick De Zwart, Werner Brack, Antonio Marcomini Jul 2006

Decision Support System For The Assessment And Evaluation Of Ecological Impacts On Aquatic Ecosystems: Objectives And Framework, Paola Agostini, Elena Semenzin, A. Critto, Christian Micheletti, Paulo Nunes, Andrea Ghermandi, Stefania Gottardo, S. Giove, Dick De Zwart, Werner Brack, Antonio Marcomini

International Congress on Environmental Modelling and Software

The EU Water Framework Directive (WFD), establishing stringent quality objectives for European basins in the next years, prompts for the development of new tools to evaluate and improve the ecological status over European rivers. The present paper will provide an overview of the main activities carried out in the DECIS subproject within MODELKEY, an European research project, funded by the European Commission, aimed to contribute to the assessment, understanding and prediction of the impacts of environmental toxicants on biodiversity in aquatic ecosystems. The main aim of DECIS is to develop a Decision Support System (DSS) that includes all project deliverables …

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Watershed Health Assessment Tools-Investigating Fisheries (What-If): A Modeling Toolkit For Watershed And Fisheries Management., Brenda Rashleigh, Craig Barber, Mike Cyterski, John Johnston, Yusuf Mohamoud, Rajbir Parmar Jul 2006

Watershed Health Assessment Tools-Investigating Fisheries (What-If): A Modeling Toolkit For Watershed And Fisheries Management., Brenda Rashleigh, Craig Barber, Mike Cyterski, John Johnston, Yusuf Mohamoud, Rajbir Parmar

International Congress on Environmental Modelling and Software

The Watershed Health Assessment Tools-Investigating Fisheries (WHAT-IF) is a decision-analysis modeling toolkit for personal computers that supports watershed and fisheries management. The WHAT-IF toolkit includes a relational database, help-system functions and documentation, and multiple statistical and simulation modeling tools. The tools consist of a hydrologic and stream geometry calculator, a fish assemblage predictor, a fish habitat suitability calculator, and a process-based model to predict biomass dynamics of stream biota (the BASS model). The tools can be used to assess conditions and associated stressors in aquatic ecosystems, to examine causes of impairment, and to forecast ecological outcomes of habitat alterations and …

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Without A Common Mental Model A Dss Makes No Sense (A New Approach To Frame Analysis Using Mental Models), M. J. Kolkman, A. Van Der Veen Jul 2006

Without A Common Mental Model A Dss Makes No Sense (A New Approach To Frame Analysis Using Mental Models), M. J. Kolkman, A. Van Der Veen

International Congress on Environmental Modelling and Software

In order to understand why the use of model software and its results in decision making is surrounded with a diversity of problems, this paper presents a new theoretical framework. The framework is based on the notions of frame and mental model that are commonly used in social sciences and psychology. Mental models are found to guide the activities of knowledge producing scientists, DSS builders, decision makers and stakeholders. These activities are described in a modelling cycle and a decision making cycle. The model – both software and mental – functions as an intermediate for knowledge transfer. The theoretical framework, …

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Future Solutions: Integrated Models For Sea And Other Land-Use Decision-Making., Ruth Waldick, David Brunckhorst, Ian Campbelld, Jeff Carmichael Jul 2006

Future Solutions: Integrated Models For Sea And Other Land-Use Decision-Making., Ruth Waldick, David Brunckhorst, Ian Campbelld, Jeff Carmichael

International Congress on Environmental Modelling and Software

Since policies should reflect societal values and aspirations, decision-making would benefit from tools that allow consideration of all entities that contribute to, or are affected by decisions. At a minimum, policy should include those key economic, social, and environmental activities taking place within a geophysically relevant area. The barriers that impede the development of integrated modeling programs that try to include many of the processes and outcomes of interest in studying a problem represent a series of common challenges associated with most integrative and cross-jurisdictional projects. Although computer-based modeling and scenario tools can inform the decision-making process, the scope of …

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Assessment Of Ecological State Of Surface Waters In Arrow Project: Robust Multivariate Predictive Models, J. Ráček, Jiri Jarkovsky, Danka Nemethova, P. Brabec Jul 2006

Assessment Of Ecological State Of Surface Waters In Arrow Project: Robust Multivariate Predictive Models, J. Ráček, Jiri Jarkovsky, Danka Nemethova, P. Brabec

International Congress on Environmental Modelling and Software

The ARROW (www.cba.muni.cz/arrow/eng - Assessment and Reference Reports of Water monitoring) project is the project of implementation of EU Water Framework Directive in the monitoring of surface waters of the Czech Republic and covers all aspects of this problem from data sampling to informatics solution (focusing on the ecostat). The project is based on long term development of this field in the Czech Republic and it is carried out under the supervision of the Ministry of the Environment of the CR. The important part of the ARROW project is the development and implementation of a Czech approach to the evaluation …

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New Directions And Challenges In Spatial Dynamic Modelling Of Ecosystem Functions In Heterogeneous Landscapes As Basis For A Better Sustainable Landscape Management, Karl-Otto Wenkel, Ralf Wieland, Wilfried Mirschel Jul 2006

New Directions And Challenges In Spatial Dynamic Modelling Of Ecosystem Functions In Heterogeneous Landscapes As Basis For A Better Sustainable Landscape Management, Karl-Otto Wenkel, Ralf Wieland, Wilfried Mirschel

International Congress on Environmental Modelling and Software

The aim of this paper is to discuss scientific challenges and new possibilities for a better modelling of consequences of land use changes in heterogeneous landscapes on ecosystem functions in space and time. The landscape or regional scale means an area of about 100 km2 up to some 1000 km2. Main problems on this scale are high complexity, structural diversity, ecological heterogeneity and uncertainty in data, in understanding of the process dynamic and by uncertainty in models.

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Application Of The Elbe-Dss To Water Quality Issues, Michael Matthies, Jürgen Berlekamp, N. Grafa, Sven Lautenbach Jul 2006

Application Of The Elbe-Dss To Water Quality Issues, Michael Matthies, Jürgen Berlekamp, N. Grafa, Sven Lautenbach

International Congress on Environmental Modelling and Software

The Decision Support System for the Elbe river basin (Elbe-DSS) was developed as a tool to assist water managers. A user can select various measures and compare them to evaluate their relative effectiveness in achieving a good ecological and chemical status of the Elbe and its tributaries. Two subsystems, the catchment and the river network, represent the whole German Elbe river basin (96.900 km2). This approach allows for better representation of management objectives, scenario development and decision-making. The implemented measures can be classified into the groups: ‘reduction of pollution from urban areas’, ‘modification of agricultural land allocation’, ‘changes in agricultural …

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Modeling Soil-Water Dynamics For Diverse Environmental Needs, Pierre Martin, Rabi H. Mohtar, Pascal Clouvel, Erik Braudeau Jul 2006

Modeling Soil-Water Dynamics For Diverse Environmental Needs, Pierre Martin, Rabi H. Mohtar, Pascal Clouvel, Erik Braudeau

International Congress on Environmental Modelling and Software

Accurate representation of the top soil matrix with special attention to the scales present is important to the dynamics of water flow and fate of pollution at field, farm and watershed scales. It is also important from an agronomic stand point since agriculture still constitutes the main source of pollution at a time when many agronomic models still use empirical notions of soil hydraulic properties. The soil dynamics literature describes soil hydraulic properties independently from the soil-water medium hydro-structural dynamics. This leads to an empirical approach to represent and estimate soil hydro-structural properties such as shrinkage, water potential, field capacity, …

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Imagine – Scenario Development For Environmental Impact Assessment Studies, T. Wagener, Y. Liu, S. Stewart, H. Hartman, M. Mahmoud Jul 2006

Imagine – Scenario Development For Environmental Impact Assessment Studies, T. Wagener, Y. Liu, S. Stewart, H. Hartman, M. Mahmoud

International Congress on Environmental Modelling and Software

Scenario analysis is a process of evaluating possible future events through the consideration of alternative possible (though not equally likely) outcomes (scenarios). The analysis is designed to enable improved decision-making and assessment through a more complete consideration of possible outcomes and their implications. The development of strategies for water resources planning and management and the assessment of impacts of potential environmental change are often guided by analyzing multiple future scenarios within an Integrated Modeling (IM) framework, usually driven by forcing derived from global climate models and/or possible future socio-economic changes. The process of scenario development involves making explicit and/or implicit …

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Data Mining As A Tool For Environmental Scientists, J. M. Spate, Karina Gibert, Miquel Sànchez-Marrè, E. Frank, Joaquim Comas, Ioannis N. Athanasiadis Jul 2006

Data Mining As A Tool For Environmental Scientists, J. M. Spate, Karina Gibert, Miquel Sànchez-Marrè, E. Frank, Joaquim Comas, Ioannis N. Athanasiadis

International Congress on Environmental Modelling and Software

Over recent years a huge library of data mining algorithms has been developed to tackle a variety of problems in fields such as medical imaging and network traffic analysis. Many of these techniques are far more flexible than more classical modelling approaches and could be usefully applied to data-rich environmental problems. Certain techniques such as Artificial Neural Networks, Clustering, Case-Based Reasoning and more recently Bayesian Decision Networks have found application in environmental modelling while other methods, for example classification and association rule extraction, have not yet been taken up on any wide scale. We propose that these and other data …

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Ribasim River Basin Planning And Management Simulation Program, Delft Hydraulics Jul 2006

Ribasim River Basin Planning And Management Simulation Program, Delft Hydraulics

International Congress on Environmental Modelling and Software

RIBASIM (River Basin Simulation Model) is a generic model package for analyzing the behaviour of river basins under various hydrological conditions. The model package is a comprehensive and flexible tool which links the hydrological water inputs at various locations with the specific water-users in the basin. RIBASIM is designed for river basin planning and management RIBASIM follows a structured approach to river basin planning and management. RIBASIM enables the user to evaluate a variety of measures related to infrastructure, operational and demand management and the results in terms of water quantity and water quality. RIBASIM generates water distribution patterns and …

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Comparison Of Linear And Non-Linear Pls Methods For Soft-Sensing Of An Sbr For Nutrient Removal, K. Villez, D. S. Lee, C. Rosen, Peter A. Vanrolleghem Jul 2006

Comparison Of Linear And Non-Linear Pls Methods For Soft-Sensing Of An Sbr For Nutrient Removal, K. Villez, D. S. Lee, C. Rosen, Peter A. Vanrolleghem

International Congress on Environmental Modelling and Software

Despite of promising results in research, advanced control strategies fail to gain trust in wastewater treatment practice. Due to the sensitivity of the biological processes to disturbances, operators are often unable to find the causes of faults due to the lack of effective real-time on-line monitoring. Strategies for on-line monitoring are therefore essential to enhance biological process control. Therefore, a suitable multivariate soft-sensor is desired for fault detection and control for a pilot-scale sequencing batch reactor (SBR) system to allow effluent quality to be estimated well before off-line analysis is finished. For this purpose, several multivariate methods are available, including …

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Dealing With Uncertainty And Sensitivity Issues In Process-Based Models Of Carbon And Nitrogen Cycles In Northern Forest Ecosystems, G. R. Larocque, J. S. Bhatti, A. M. Gordon, N. Luckai, Jinxun Liu, Shuguang Liu, P. A. Arp, C. -F Zhang, Alexander Komarov, Pavel Grabarnik, M. Wattenbach, C. Peng, Jianfeng Sun, Thomas White Jul 2006

Dealing With Uncertainty And Sensitivity Issues In Process-Based Models Of Carbon And Nitrogen Cycles In Northern Forest Ecosystems, G. R. Larocque, J. S. Bhatti, A. M. Gordon, N. Luckai, Jinxun Liu, Shuguang Liu, P. A. Arp, C. -F Zhang, Alexander Komarov, Pavel Grabarnik, M. Wattenbach, C. Peng, Jianfeng Sun, Thomas White

International Congress on Environmental Modelling and Software

Many process-based models on carbon (C) and nitrogen (N) cycles have been developed for northern forest ecosystems. These models are widely used to evaluate the long-term decisions in forest management dealing with effects like particulate pollution, productivity and climate change. Regarding climate change, one of the key questions that have sensitive political implications is whether northern forests will sequester atmospheric C or not. Whilst many process-based models have been tested for accuracy by evaluating or validating against observed data, few have dealt with the complexity of the incorporated procedures to estimate uncertainties associated with model predictions or the sensitivity of …

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Data Mining And Image Segmentation Approaches For Classifying Defoliation In Aerial Forest Imagery, K. Fukuda, P. A. Pearson Jul 2006

Data Mining And Image Segmentation Approaches For Classifying Defoliation In Aerial Forest Imagery, K. Fukuda, P. A. Pearson

International Congress on Environmental Modelling and Software

Experimental data mining and image segmentation approaches are developed to add insight towards aerial image interpretation for defoliation survey procedures. A decision tree classifier generated with a data mining package, WEKA [Witten and Frank, 2005], based on the contents of a small number of training data points, identified from known classes, is used to predict the extents of regions containing different levels of tree mortality (severe, moderate, light and non attack) and land cover (vegetation and ground surface). This approach is applicable to low quality imagery without traditional image pre-processing (e.g., normalization or noise reduction). To generate the decision tree, …

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Uncertainty Management, Spatial And Temporal Reasoning, And Validation Of Intelligent Environmental Decision Support Systems, Miquel Sànchez-Marrè, Karina Gibert, Rick Sojda, Jean-Philippe Steyer, Peter Struss, Ignasi Rodríguez-Roda Jul 2006

Uncertainty Management, Spatial And Temporal Reasoning, And Validation Of Intelligent Environmental Decision Support Systems, Miquel Sànchez-Marrè, Karina Gibert, Rick Sojda, Jean-Philippe Steyer, Peter Struss, Ignasi Rodríguez-Roda

International Congress on Environmental Modelling and Software

There are inherent open problems arising when developing and running Intelligent Environmental Decision Support Systems (IEDSS). During daily operation of IEDSS several open challenge problems appear. The uncertainty of data being processed is intrinsic to the environmental system, which is being monitored by several on-line sensors and off-line data. Thus, anomalous data values at data gathering level or even uncertain reasoning process at later levels such as in diagnosis or decision support or planning can lead the environmental process to unsafe critical operation states. At diagnosis level or even at decision support level or planning level, spatial reasoning or temporal …

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Helping Children To Be Lifelong Learners, Don Pearson, Ann Pearson Jul 2006

Helping Children To Be Lifelong Learners, Don Pearson, Ann Pearson

Religious Educator: Perspectives on the Restored Gospel

No abstract provided.

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Moira-Plus: A Decision Support System For The Management Of Complex Fresh Water Ecosystems Contaminated By Radionuclides And Heavy Metals, Luigi Monte, Lars Håkanson, D. Hofman, John Brittain, Eduardo Gallego, Antonio Jimenez, Giacomo Angeli Jul 2006

Moira-Plus: A Decision Support System For The Management Of Complex Fresh Water Ecosystems Contaminated By Radionuclides And Heavy Metals, Luigi Monte, Lars Håkanson, D. Hofman, John Brittain, Eduardo Gallego, Antonio Jimenez, Giacomo Angeli

International Congress on Environmental Modelling and Software

The accidental release of radioactive substances into the environment leads to the necessity of applying suitable countermeasures for the restoration of the polluted environment. However, despite their obvious benefits, such interventions may result in detrimental effects of economic, ecological and social nature that must be carefully evaluated. MOIRA–PLUS is a PC-based user-friendly, Computerised Decision Support System (CDSS) that helps decision makers to choose optimal countermeasure strategies for different kinds of aquatic ecosystems and contamination scenarios. CDSS MOIRA-PLUS is based on: a) Validated models to evaluate the behaviour of radionuclides in contaminated water bodies and biota and to assess the effect …

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Challenges Encountered During Integrated Modelling Across Multiple Catchments, Neville D. Crossman, Brett A. Bryan Jul 2006

Challenges Encountered During Integrated Modelling Across Multiple Catchments, Neville D. Crossman, Brett A. Bryan

International Congress on Environmental Modelling and Software

There has been a recent trend in natural resource management decision making toward target setting and the use of models to identify geographic priorities to meet those targets. However, measurable and quantitative targets for assessing progress toward achieving management and policy goals tend not to be established. This may be due in large part to a lack of clarity in data and model availability, and geographic prioritisation processes. The long history of extensive human activity and modification of natural resources in the Murray Darling Basin of southern Australia has led to a myriad of natural resource management problems, particularly dryland …

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On The Prediction Of The Ecological Status Of Human-Altered Streams And Its Rule-Based Interpretation, Terence A. Etchells, Alfredo Vellido, E. Martí, Paulo J. G. Lisboa, Joaquim Comas Jul 2006

On The Prediction Of The Ecological Status Of Human-Altered Streams And Its Rule-Based Interpretation, Terence A. Etchells, Alfredo Vellido, E. Martí, Paulo J. G. Lisboa, Joaquim Comas

International Congress on Environmental Modelling and Software

The recent Water Framework Directive of the European Union set year 2015 as their target for freshwater and coastal ecosystems all across Europe to achieve good ecological status. This study concerns the analysis of the empirical data from the knowledge base of an environmental decision support system developed within the European project STREAMES. These data, which come from several low-order streams located mostly on the Mediterranean region, consist of measurements of several physical, chemical and biological variables. We aim to classify these data according to the ecological status of the streams they correspond to, where stream nutrient retention efficiency (a …

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Ecohydraulics In The Mississippi River: Freshwater Mussel Dynamics Model, J. A. Daraio, Y. Morales-Chaves, Arthur E. Mynett, L. Weber Jul 2006

Ecohydraulics In The Mississippi River: Freshwater Mussel Dynamics Model, J. A. Daraio, Y. Morales-Chaves, Arthur E. Mynett, L. Weber

International Congress on Environmental Modelling and Software

The family Unionidae (freshwater mussels) is geographically diverse with species found worldwide; their greatest diversity is found in North America. Zebra mussels (Dreissena polymorpha) are an exotic species introduced into North America in the 1980’s that has since become a threat to economic interests and native mussel species in the region. IIHR-Hydroscience and Engineering and WL|Delft Hydraulics are developing a numerical model of mussel population dynamics for the purpose of analyzing alternative management strategies of zebra mussels and Unionidae in the Upper Mississippi River (UMR). The Mussel Dynamics Model (MDM) simulates interaction of mussels and the hydraulic environment. This paper …

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Finding Relevant Features For The Characterization Of The Ecological Status Of Human Altered Streams Using A Constrained Mixture Model, Alfredo Vellido, Joaquim Comas, Raul Cruz, Eugenia Marte Jul 2006

Finding Relevant Features For The Characterization Of The Ecological Status Of Human Altered Streams Using A Constrained Mixture Model, Alfredo Vellido, Joaquim Comas, Raul Cruz, Eugenia Marte

International Congress on Environmental Modelling and Software

The large dimensionality of real data sets usually hampers the interpretability of the results of their analysis. In a previous study, some stream data that are part of the knowledge base of an environmental decision support system were explored through clustering and visualization. The interpretability of these clustering results would be improved by the use of a feature selection strategy based on a method capable of ranking the observed features according to their relative relevance. In this paper, we use one such a method that is an integral part of a probabilistic model for multivariate data clustering and visualization: Generative …

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