Digital Commons Network^™

Participatory Decision Making In Reservoir Planning, R. Soncini-Sessa, A. Castelletti, E. Weber

International Congress on Environmental Modelling and Software

The technologies and methods for integrated planning and management of water resource systemshave matured considerably over the past decades. However, relatively few of them have been actually and regularlyapplied in real world decisional processes. We feel this is essentially due to a general lack of engagementof stakeholders and decision makers at every stage of the decisional process. Innovative methodologies andtools to improve participation are presented, with focus on water reservoir systems

The Control Of Algal Bloom Damages To Clam Yield In A North Adriatic Coastal Lagoon (Sacca Di Goro, Italy), F. Cellina, G. A. De Leo, M. Bartoli, P. Viaroli

International Congress on Environmental Modelling and Software

During the last twenty years the economic activity of clams exploitation has been intensively developed in the southernmost coastal lagoon of the Italian Po river delta, Sacca di Goro. Still, clam breeding is in danger because of frequent summer algal blooms, due to Ulva rigida macroalgae. These blooms cause anoxic crises leading clams to collapse, with a consequent deep impact on the whole economic sector of clams exploitation. Several strategies have been developed to avoid the loss of commercial production, yet none of them has been assessed on a mathematical basis. In this work we develop a simple stochastic mathematical …

Sensitivity Of Different Evapotranspiration Calculation Methods In Different Crop-Weather Models, J. Eitzinger, D. Marinkovic, J. Hosch

International Congress on Environmental Modelling and Software

The calculation of evapotranspiration and its components transpiration and evapotranspiration is of crucial importance in dynamic crop-weather models, irrigation models and SVAT models. Although many approaches were developed and adapted for various applications and based on available input data, there is still a remarkable range of uncertainty related for a representative calculation. However, many of the problems are based on weak quality of model input data, but others are related to the method itself and its sensitivity to various environmental conditions. In our study, several methods of evapotranspiration estimation in different crop weather models are compared and tested against data …

Systematic Risks, Speculators And The Forward Rate Puzzle, Kim Radalj

International Congress on Environmental Modelling and Software

An often-cited explanation for the forward rate puzzle is that predictions obtained under risk neutrality do notapply in a world where the typical agent is risk averse. Thus, ignoring risk premiums in empirical testing amounts tomisspecification, which may unduly influence the estimated coefficients. Whether risk premiums exist in currencymarkets is especially important to those exposed to international commodity and financial markets, as there areimplications for both hedging strategies and the expectations formation process. This paper focuses upon two possiblesources of premia, namely systematic risk arising from market portfolio risk and secondly, the influence of speculativepressures upon currency markets. Perusal of …

Modeling Spatial Spread Of Genetic Information Via Pollen Dispersal: Coupling Of Population Dynamics And Genetics, O. Richter, Ralf Seppelt

International Congress on Environmental Modelling and Software

The spatial spread of pollen is modeled by transport equations from atmospheric physics. These equations are coupled with a population dynamic and genetic model. The resulting model consists of a set of coupled partial differential equations which is solved by finite element methods. Due to recent advances in software tools it is possible to solve complex systems of partial differential equations within reasonable computing time. Simultaneous simulation of spatial spread and population genetics enable the evaluation of anti-resistance management strategies.

Probabilistic Ecological Risk Assessment Framework For Chemical Substances, F. A. M. Verdonck, J. Jaworska, C. R. Janssen, Peter A. Vanrolleghem

International Congress on Environmental Modelling and Software

The goal of probabilistic ecological risk assessment (PERA) is to estimate the likelihood and the extent of adverse effects occurring to ecological systems due to exposure(s) to substances. It is based on the comparison of an exposure concentration distribution (ECD) with a species sensitivity distribution (SSD) derived from chronic toxicity data. A PERA framework was proposed and illustrated with a case study on the pesticide atrazine in the surface waters of Flanders. The risk and its uncertainty or confidence interval can be visualised in a pie chart. A probabilistic approach results in a more realistic environmental risk assessment and therefore …

Avenues Of Spatially Explicit Population Dynamics Modeling — A Par Excellence Example For Mathematical Heterogeneity In Ecological Models?, Ralf Seppelt

International Congress on Environmental Modelling and Software

This contribution discusses different approaches to spatially explicit modeling of population dynamics of the intrusion of non-endemic species into patched habitats. Different modeling approaches such as cellular automata, partial differential equations and hybrid Petri nets are summarized. An application of a meta–population model for the Galapagos archipelago is described using a partial differential equation and a Petri net model. A detailed comparison of both models in terms of simulation results and methodology shows how different building blocks of ecological models can be. And the question is raised, how far the integration of models is at all possible and should be …

Integrating Mechanistic Modelling And Statistical Learning Theoretic-Methods: Initial Steps Toward A Strategy For Model Evaluation And Structure Selection, A. Guergachi

International Congress on Environmental Modelling and Software

The traditional model validation procedure has been criticized in many areas of environmentalengineering. In this paper, it is suggested to replace it by a more reasonable procedure: “model evaluation”.A framework for model evaluation and structure selection (FMESS) is presented. Based on statisticallearning theory, this framework considers the model identification step as a learning problem. The modelevaluation process is based on one single criterion: model performance. The latter is measured by amathematical deviation between the model prediction and reality. Although it is an exact measure of modelperformance, this deviation cannot be computed, but can be related to the empirical measure that …

Evaluating Management Strategies In Paraguacu River Basin By Analytic Hierarchy Process, B. Srdjevic, Y. Medeiros, Z. Srdjevic, M. Schaer

International Congress on Environmental Modelling and Software

An approach is proposed for evaluating water management strategies in river basins. Reasonably large sets of criterions and objectives are manipulated during a three-phase process by appropriate shrinking and enlarging related decision hierarchies. In the first phase an unrestricted set of management interests are grouped into (1) long-term, and (2) middle- and short-term decision context by creating decision hierarchies and evaluating them by the Analytic Hierarchy Process (AHP). After refining the hierarchies by deleting dominated elements, management plans are introduced at their fingertips and so enlarged hierarchies are repeatedly evaluated by AHP in the second phase. Only two bottom levels …

Spatial Correlation Analysis Of Nitrogen Dioxide Concentrations In The Area Of Milan, Italy, Grégoire Dubois, M. Saisana, A. Chaloulakou, N. Spyrellis

International Congress on Environmental Modelling and Software

Monitoring atmospheric pollution in urban areas frequently involves mapping techniques that assist the researcher and/or the decision-maker to describe and quantify the pollution at locations where no measurements are available. The preparation of these pollution maps is a complex task, which is only feasible if a spatial correlation of the variable of interest is identified. Furthermore, the spatial correlation may not only change in time and space, but also according to the pollution levels. To illustrate this point, this paper investigates the fractal dimension of the spatial correlation of different levels of annual nitrogen dioxide concentrations [NO2] in the greater …

On Line Simulation System For Industrial Accidents, R. Bellasio, R. Bianconi

International Congress on Environmental Modelling and Software

Mathematical models are important tools to evaluate the consequences of possible industrialaccidents. These models are often difficult to apply because they require trained users, and graphical userinterfaces can be of great help. An on line simulation system has been developed and is installed as a serversideapplication on the internet at www.enviroware.it. The system currently contains two models, EXPSYSis suitable to carry out consequence analysis and allows the user to evaluate the area impacted by industrialaccidents such as explosions, fires and releases of toxic or flammable gases. TOXFLAM is an analytic modelsuitable for simulating the atmospheric dispersion of gases lighter than …

Exploration Of The Behaviour Of A Stochastic Transport Model Using Computational Experiments, C. Rajanayaka, D. Kulasiri

International Congress on Environmental Modelling and Software

Fickian assumptions are used in deriving the advection-dispersion equation which models thesolute transport in porous media. The hydrodynamic dispersion coefficient defined as a result of theseassumptions has been found to be scale dependent. Kulasiri and Verwoerd [1999] developed a stochasticcomputational model for solute transport in saturated porous media without using Fickian assumptions. Themodel consists of two main parameters; correlation length and variance, and the velocity of solute wasassumed as a fundamental stochastic variable. In this paper, the stochastic model was investigated tounderstand its behaviour. As the statistical nature of the model changes with the parameters, thecomputational solution of the model …

A Conceptual Approach To Multiple-Model Integration In Whole Site Risk Assessments, E. P. Albers, K. R. Dixon

International Congress on Environmental Modelling and Software

In the past, models have focused on one environmental compartment, a single organism, or specific process. All of these topics are limited in scope and often fail to take into account the more complex interactions of the real world. We have endeavored to change this practice by combining environmental transport models with an animal movement model and a physiologically based toxicokinetics (PBTK) model that has an embedded effects model. The example we will depict consists of a hypothetical contaminant plume within a lake and the impacts on the channel catfish (Ictalurus punctatus). We compared the PBTK output for the multiple-model …

An Artificial Neural Networks Modeling Approach Applied To The Probabilistic Management Of Water Resources Systems, J. C. Ochoa-Rivera, R. García-Bartual, J. Andreu

International Congress on Environmental Modelling and Software

A multivariate non-linear model for synthetic generation of monthly discharge series is presented. The time series generator is built upon a multilayer feedforward neural network with an added multivariate random component normally distributed. The usual error backpropagation algorithm is used to train the network, with a sequential training scheme using shuffled patterns for a stochastic search in the weight space. The proposed model generates inputs to a wider methodology developed for simulation of the probabilistic managing of the upper Tagus River system in Spain. The model is validated in terms of its ability to reproduce some relevant statistics directly related …

Environmental Risk Assessment Of Pesticide Use Based On The Modelling Of The Environmental Fate Of Pesticides In Soil, Heico Apel, O. Richter

International Congress on Environmental Modelling and Software

Based on laboratory and field experiments the environmental fate of four selected pesticides (Dimethoate, Fenvalerate, Malathion, and Metalaxyl) in the Jhikhu-Khola watershed, Nepal was investigated, both on soils representative for irrigated (khet) and rainfed (bari) conditions. The degradation, sorption, and transport behaviour were described with deterministic mathematical models. Based on these models a risk assessment of the accumulation of the pesticides in soil and groundwater was conducted. In order to achieve this standard, worst and best case scenarios were developed. The framework and conditions for the scenarios were set by the physical and socio-economic environment in the watershed, which was …

Process-Based Ecohydrological Modelling At The River Basin Scale And Options For Regionalisation, Valentina Krysanova, Fred Hattermann, Frank Wechsung

International Congress on Environmental Modelling and Software

The paper discusses the importance of physical basis and level of complexity in ecohydrological models at the catchment scale, their spatial structure and temporal resolution, and preconditions for regional applications of models of that kind. As an example, the process-based ecohydrological model SWIM developed for integrated modelling of interrelated hydrological processes, vegetation dynamics and nutrient cycling at the river basin scale is presented along with examples of its validation and a regional climate impact case study.

Hydrotope-Based River Flow Simulation In A Swiss Alpine Catchment Accounting For Topographic, Micro-Climatic And Landuse Controls, A. Salvetti, W. Ruf, P. Burlando, U. Juon, C. Lehmann

International Congress on Environmental Modelling and Software

An application of the Precipitation Runoff Modelling System (PRMS) based on the concept ofHydrological Response Units (HRUs) is presented for hydrological modelling of an alpine catchment. This isthe Aare River catchment upstream of the Lake Thun, in the Bernese Oberland Region, Switzerland, which ischaracterised by large glacierised areas. Accounting for these areas required to develop further the originalPRMS, which was rarely used in alpine regions. Particular attention was devoted to the analysis of the temporaland spatial distribution of temperature and rainfall within the catchment. The derivation of distributedmodel’s parameters was based on an extensive database of catchment characteristics available for …

Management Of Contamination Risks And Identification Of Contamination Sources, A. Kryazhimskii, V. Maksimov

International Congress on Environmental Modelling and Software

Some aspects of management of contamination risks based on monitoring contamination sources areunder consideration. The case when direct measurements are impossible and the values of the contaminationinputs should be estimated through observations of indirect indicators is studied. Standard mathematical modelsdescribing the diffusion of a contaminant in the form of partial differential equations of the parabolic type areused. A model-based technique for the reconstruction of the evolution of the intensities of point-concentratedcontamination sources through observations of the concentration of the contaminant is presented. Results ofnumerical experiments are discussed.

Integrated Simulation Of Urban Drainage System And Receiving Water Body During Rainfall Events For Both Quantity And Quality Aspects, Marco Maglionico

International Congress on Environmental Modelling and Software

This work describes a mathematical model for the integrated simulation of the urban drainage system and the receivingwater body during rainfall events.The developed model, UPSIM (Maglionico, 1998), is a simplified conceptual model that schematised the sewernetworks in several sub-catchments and the river in several stretch, each one simulated with linear canals and reservoirs.For the sewer network, starting from the data recorded by the rain gauges, the model evaluates the net rainfallconsidering the hydrological losses on the catchment; the flow entering in the network through the gully pots isevaluated considering the catchment as a linear reservoir. The network is assumed to …

Environmental Data Mining And Modelling Based On Machine Learning Algorithms And Geostatistics, M. Kanevski, R. Parkin, A. Pozdnukhov, V. Timonin, M. Maignan, B. Yatsalo, S. Canu

International Congress on Environmental Modelling and Software

The paper presents some contemporary approaches to the spatial environmental data analysis, processing and presentation. The main topics are concentrated on the decision–oriented problems of environmental and pollution spatial data mining and modelling: valorisation and representativity of data with the help of exploratory data analysis, topological, statistical and fractal measures of monitoring networks, spatial predictions and classifications, probabilistic and risk mapping, development and application of conditional stochastic simulation models. The set of tools used consists of machine learning algorithms (MLA) – Multilayer Perceptron, General Regression Neural Networks, Probabilistic Neural Networks, Radial Basis Function Networks, Support Vector Machines and Support Vector …

A Comparison Between The Uncertainties In Model Parameters And In Forcing Functions: Its Application To A 3d Water Quality Model., R. Pastres, S. Ciavatta

International Congress on Environmental Modelling and Software

This paper presents the application of both local and global sensitivity analysis techniques to anestimation of the uncertainty of the output of a 3D reaction-diffusion ecological model, which describes theseasonal dynamics of dissolved Nitrogen and Phosphorous, and that of the phytoplanktonic andzooplanktonic communities in the lagoon of Venice. Two sources of uncertainty were taken into account andcompared: 1) uncertainty concerning the parameters of the governing equation; 2) uncertainty concerning theforcing functions. The mean annual concentrations of Dissolved Inorganic Nitrogen, DIN, was regarded asmodel output, as the current Italian legislation sets a quality target for Total Dissolved Nitrogen in the lagoonof …

The Facilitator - An Open Source Effort To Support Multiobjective Decision Making, P. Heilman, Greg Davis, Paul Lawrence, Jerry L. Hatfield, John Huddleston

International Congress on Environmental Modelling and Software

Multiobjective Decision Support technology has matured to the point where new efforts should incorporate components of existing systems, rather than build everything from scratch. To help such efforts, the Java source code to a multiobjective decision support system called “The Facilitator” has been revised and released under the Mozilla Public License. This open source effort will be of interest to three groups. First, anyone needing a tool for multiobjective decision support can use the Facilitator. Users familiar with Java can now see how actions in the Facilitator are implemented or modify the user interface. Second, the open source approach might …

Vibrational Modes Of Thin Oblate Clouds Of Charge, Thomas G. Jenkins, Ross L. Spencer

Faculty Publications

A numerical method is presented for finding the eigenfunctions (normal modes) and mode frequencies of azimuthally symmetric non-neutral plasmas confined in a Penning trap whose axial thickness is much smaller than their radial size. The plasma may be approximated as a charged disk in this limit; the normal modes and frequencies can be found if the surface charge density profile sigma(r) of the disk and the trap bounce frequency profile wz(r) are known. The dependence of the eigenfunctions and equilibrium plasma shapes on nonideal components of the confining Penning trap fields is discussed. The results of the calculation are compared …

An Enterprise-Based Grid Resource Management System, Mark J. Clement, Joseph Ekstrom, Quinn O. Snell, Kevin B. Tew

Faculty Publications

As the Internet began its exponential growth into a global information environment, software was often unreliable, slow and had difficulty in interoperating with other systems. Supercomputing node counts also continue to follow high growth trends. Supercomputer and grid resource management software must mature into a reliable computational platform in much the same way that web services matured for the Internet. DOGMA The Next Generation (DOGMA-NG) improves on current resource management approaches by using tested off-the-shelf enterprise technologies to build a robust, scalable, and extensible resource management platform. Distributed web service technologies constitute the core of DOGMA-NG’s design and provide fault …

Machine-Learned Contexts For Linguistic Operations In German Sentence Realization, Eric K. Ringger, Simon Corston-Oliver, Michael Gamon, Robert Moore

Faculty Publications

We show that it is possible to learn the contexts for linguistic operations which map a semantic representation to a surface syntactic tree in sentence realization with high accuracy. We cast the problem of learning the contexts for the linguistic operations as classification tasks, and apply straightforward machine learning techniques, such as decision tree learning. The training data consist of linguistic features extracted from syntactic and semantic representations produced by a linguistic analysis system. The target features are extracted from links to surface syntax trees. Our evidence consists of four examples from the German sentence realization system code-named Amalgam: case …

Intelligent Segmentation Tools, William A. Barrett, Eric N. Mortensen, L. Jack Reese

Faculty Publications

Intelligent Scissors and Intelligent Paint are complementary interactive image segmentation tools that allow a user to quickly and accurately select objects of interest using simple gesture motions with a mouse. With Intelligent Scissors. when the cursor position comes in proximity to an object edge, a live-wire boundary “snaps” to, and wraps around the object of interest. The Intelligent Paint tool uses the cursor position to sample the image data interior to the object and grows the current region, in discrete, snapping increments, to include similar neighboring regions. Both techniques make use of a watershed algorithm called toboganning. Wth Intelligent Scissors, …

Validation Of Sea Ice Motion From Quikscat With Those From Ssm/I And Buoy, David G. Long, Yunhe Zhao, Antony K. Liu

Faculty Publications

Arctic sea ice motion for the period from October 1999 to March 2000 derived from QuikSCAT and ocean buoy observations. Special Sensor Microwave/Imager (SSM/I) data using the wavelet analysis method agrees well with ocean buoy observations. Results from QuikSCAT and SSM/I are compatible when compared with buoy observations and complement each other. Sea ice drift merged from daily results from QuikSCAT, SSM/I, and buoy data gives more complete coverage of sea ice motion. Based on observations of six months of sea ice motion maps, the sea ice motion maps in the Arctic derived from QuikSCAT data appear to have smoother …

Elasticity In Microstructure Sensitive Design Through The Use Of Hill Bounds, Benjamin L. Henrie

Theses and Dissertations

In engineering, materials are often assumed to be homogeneous and isotropic; in actuality, material properties do change with sample direction and location. This variation is due to the anisotropy of the individual grains and their spatial distribution in the material. Currently there is a lack of communication between the design engineer, material scientist, and processor for solving multi-objective/constrained designs. If communication existed between these groups then materials could be designed for applications, instead of the reverse. Microstructure sensitive design introduces a common language, a spectral representation, where both design properties and microstructures are expressed.

Using Hill bounds, effective elastic properties …

Improving Speech Recognition Learning Through Lazy Training, Tony R. Martinez, Michael E. Rimer, D. Randall Wilson

Faculty Publications

Multi-layer backpropagation, like most learning algorithms that can create complex decision surfaces, is prone to overfitting. We present a novel approach, called lazy training, for reducing the overfit in multiple-layer networks. Lazy training consistently reduces generalization error of optimized neural networks by more than half on a large OCR dataset and on several real world problems from the UCI machine learning database repository. Here, lazy training is shown to be effective in a multi-layered adaptive learning system, reducing the error of an optimized backpropagation network in a speech recognition system by 50.0% on the TIDIGITS corpus.

Network Simplification Through Oracle Learning, Tony R. Martinez, Joshua Menke, Adam Peterson, Michael E. Rimer

Faculty Publications

Often the best artificial neural network to solve a real world problem is relatively complex. However, with the growing popularity of smaller computing devices (handheld computers, cellular telephones, automobile interfaces, etc.), there is a need for simpler models with comparable accuracy. The following research presents evidence that using a larger model as an oracle to train a smaller model on unlabeled data results in 1) a simpler acceptable model and 2) improved results over standard training methods on a similarly sized smaller model. On automated spoken digit recognition, oracle learning resulted in an artificial neural network of half the size …