Organiser: Robin T Clarke (clarke@iph.ufrgs.br)

Models of biological, environmental and ecological systems are becoming increasingly complex, and studies to compare the performances of alternative models are now very common. A typical procedure is to test a number of candidate models on each of several data-sets; in each data-set, part of the data is used for model calibration, and another part is set aside for model validation, i.e., seeing how well each model performs under conditions not experienced during calibration. Several measure of performance are specified a priori for comparing different models with a standard, and/or for testing differences between candidate models. Since comparisons between complex models are time-consuming and costly, it is important that they be carefully designed so that firm conclusions can be drawn about relative model performance. The session will explore whether inter-comparisons between complex models can benefit from the well- established statistical principles of experimental design (randomisation, replication... ) widely used in many other fields of science: and if so, how far.

Organisers: Phil Pollett (pkp@maths.uq.edu.au), Fionnuala Buckley (fbuckley@maths.uq.edu.au) and Sam Nicol (snicol@maths.uq.edu.au), Department of Mathematics The University of Queensland

A metapopulation is a population that is confined to a network of geographically separated habitat patches. Although the individual patches may suffer local extinction, recolonization may occur through dispersal of individuals from other patches. Empirical evidence suggests that a balance between migration and extinction is reached that enables metapopulations to persist for long periods, and there has been considerable interest in developing models which account for the persistence of the population network. These models have been used as a basis for decision making in the management of ecological systems, and optimization techniques are being developed to answer questions such as whether it is best to protect habitat or to create new habitat under budgetary constraints. We welcome submissions from researchers and practitioners working in the modelling and control of populations. Selected papers from this session will appear in a special issue of "Ecological Modelling".

Organisers: Timothy R. Green, USDA-ARS, (tim.green@ars.usda.gov), Murugesu Sivapalan, James C. Ascough II, USDA-ARS, (jim.ascough@ars.usda.gov)

"Process Interactions in the Environment" was a special session at MODSIM 97. We propose to revisit this topic with attention to advances in the last decade and increased emphasis on interactions in space and time. A full appreciation of the workings of the natural and managed environment requires understanding of the interactions between various processes at a variety of spatial and temporal scales. Integration of agricultural, ecological and hydrogeological systems is encouraged within the space-time continuum. The proposed special session will be a combination of modeling, scaling, and field measurement approaches aimed at gaining insights into process interactions and space-time feedback. Possible categories of presentations will include: 1) process oriented modeling with biophysical interpretations based on model constructs and measurements; 2) simulation and analyses of spatial patterns, connectivity and space-time feedback; and 3) data-driven relationships between system state variables and fluxes. Insights gained from improved understanding of such process interactions can be linked to management decisions across agricultural and environmental sectors.

Organisers: Andre Zerger (andre.zerger@csiro.au), Shawn Laffan (Shawn.Laffan@unsw.edu.au) and David Pullar (d.pullar@uq.edu.au)

This session focuses on the integration of two adjacent fields of geographical information science and environmental modelling. The technology of GIS is well established with tools for management, visualisation, and analysis of environmental information. With system interoperability GIS may be coupled to different types of environmental models, or alternatively new geoprocessing operations are being developed to directly support environmental modelling within GIS. There are also new paradigms emerging that relate spatial patterns to environmental landscape processes. This session invites papers on integrating GIS and environmental models that address technology issues, methodologies and innovative applications in the areas of geoprocessing , coupled models, spatial analysis to relate pattern with landscape processes , and development of methodologies for spatial decision support.

Organisers: Suppiah Ramasamy (Suppiah.Ramasamy@csiro.au)
Josef Syktus (Jozef.Syktus@climatechange.qld.gov.au)
Ian Smith (Ian.Smith@csiro.au)

Modelling and experimental studies to understand the status of the condition, trend and interdependencies of the ecosystem of the tropical rainforest region of North Queensland and developing methods to maintain the ecosystem with sustainable development under climate change conditions. Understanding the threats to, and their impacts on the environment in the tropical rainforest region and developing options to mitigate them. Hydrological modelling to understand the causes and effects of changing water quality and water resource use in the tropical rainforest region and coastal catchments; developing options for improving practices, reducing risks and mitigating adverse impacts.

This session can include papers dealing with the impact t of climate change on spatial distribution of fauna and flora of this region. Specifically, papers dealing with regional climate change of this area, impacts on vegetation, and changes in species distribution and water resources can be included.

Organisers: Richard Little (Rich.Little@csiro.au) CSIRO,
Olivier Thebaud (Olivier.Thebaud@ifremer.fr) IFREMER

As both the intensity and breadth of human utilisation in the marine environment increases, understanding the natural patterns and processes and associated human interactions in it is complex, but vitally important. As most of the marine environment is unseen, and not conducive to cost-effective observational science, modelling and simulation represents an effective means of developing a better understanding of marine ecosystems by encapsulating and simplifying the representation of our knowledge. For this session contributions are welcome from basic and applied modelling of fisheries and marine natural resources. This includes areas such as integrated socio-economic modelling , stock assessment, ecosystem modelling, agent-based modelling, and complex system science approaches along with decision support systems, management strategy evaluation, and marine reserve design.

Organiser: Khorshed Alam (alam@usq.edu.au), University of Southern Queensland

Emission trading, a form of economic incentive mechanism in environmental policy making, has appeared to be the key approach of many Western economies to controlling greenhouse gases. It will be of interest to researchers, policy makers and business to assess various aspects of this emerging concept from a multidisciplinary perspective. The session will comprise, but is not restricted to, theoretical and/or applied/ empirical works in the following areas:

• Market-based approaches to environmental policy
• Economics of emission trading: Concepts and analytical tools
• Emission trading: Macro-and-microeconomic impacts, adaptations and vulnerability
• Design and evaluation of emissions trading schemes
• Modelling the climate and carbon emission trading
• Problems and potentials of climate/emission trading research
• Emission trading and sustainability
• Emission trading: costs and benefits, compliance and enforcement
• Opportunities and challenges of including agriculture and forestry under ETS
• Role of institution building
• lessons from existing trading schemes for the control of greenhouse gases

Organisers: Dr Chris Pettit (Christopher.Pettit@dpi.vic.gov.au),
Prof Ian Bishop (i.bishop@unimelb.edu.au)
Prof Shattri Mansor (Shattri@eng.upm.edu.my)
Dr Jean-Philippe Aurambout (jeanphilippe.aurambout@dpi.vic.gov.au)

There are many tools and techniques available for visualising landscape processes and condition (existing and future). Visualisation can provide a window to complex biophysical and socio-economic models and can assist communities, industry and decision-makers better understand landscape condition and the likely impact of land management decisions. This session will provide a forum to report and critique the latest developments and applications in landscape visualisation. Papers that describe the application and/or recent developments of landscape visualisation technologies such as digital globes, online collaborative environments, computer gaming engines, virtual reality and augmented reality are encouraged. Possible areas of interest include: visualisation tools and techniques for exploring both natural and built landscapes under a changing climate, visualisation as a front end for complex models, and studies which evaluate the usability and usefulness of visualisation technologies for spatial decision support.

This session will be run in conjunction with ISPRS Working Groups II 6 - Geographical Visualization and Virtual Reality and WG II 7 - Spatial Decision Support Systems

Organisers: Peter A. Khaiter (pkhaiter@yorku.ca), York University, Canada,
Marina G. Erechtchoukova (marina@yorku.ca), York University, Canada

The section is aimed to bring together mathematicians, modelers, environmental economists and ecologists working in the area of sustainable environmental development and management. Sustainability assumes decisions which satisfy current needs without compromising the interests of the future generations. The concept implies the necessity to predict and compare the dynamics of natural ecosystems with and without human impact. Simulation models and other mathematical techniques are widely used as the tools to generate such predictions. The conformity of the modeling predictions with the real behavior of ecosystems and environmental objects is one of the most fundamental issues. It is important to understand to what extent the conclusions drawn from models, their mathematical properties and modeling results reflect the behaviour of real world ecosystems, including their stability properties, and what theories and approaches are suitable for such an analysis. The session is open to new paradigms and technologies/tools to support sustainable environmental development and management. Comparative discussions on potentials and limits of different modelling approaches are within the scope of this session. Applied methods and tools including frameworks for mathematical analysis of the models and case studies are also welcome.

Organisers: Stefan Reis, CEH Edinburgh (srei@ceh.ac.uk)
Tiziano Pignatelli, ENEA (pignatelli@casaccia.enea.it)

The proposed session invites contribution to model developers and those applying models for the integrated assessment of strategies to improve air quality and to reduce greenhouse gas emissions and releases of pollutants into environmental media other than air. In this context, models addressing either part of or the full chain from drivers to pressures and state of the environment to responses are at the heart of this session.

For these most often complex models/model frameworks, in particular when the need arises to link and couple different specialist models to conduct a full impact assessment using a full-chain approach (reference), issues of scale are often critical and need to be addressed by modellers and decision makers alike.

In addition to that, the variety of impacts of air pollutants both on ecosystems and on human health and the often conflicting targets, in particular taking into account the objectives to reduce emissions of greenhouse gases at the same time, present challenges to modellers and policy makers alike. On the one hand, detailed process level models of e.g. ecosystem services, responses to critical load exceedances or exposure-effect relationships for human health effects are needed. On the other hand, policy decision making requires robust and transparent model results to base policy development on. Current examples for applications of integrated assessment models, for instance in Europe, the US and Canada in the frame of the UNECE Convention on Long-Range Transboundary Air Pollution, address ecosystem impacts and human health effects in a coordinated way.

The target audience and expected contributions will be model developers and researchers working on complex models, including the integration/coupling of models, delivering papers and presentations on innovative approaches and methodology addressing the full scope of the session as outlined above. To complement this, specific research covering key aspects of work across spatial and temporal scales of high relevance is welcome. Papers should address aspects of integration, e.g. across spatial scales, environmental media, time, environmental problems (e.g. dynamic modelling of ecosystem recovery, exposure of population to ambient concentrations of air pollutants in space and time, etc.). Presenters will be asked to allow for thorough discussions of their methodology and if time allocated to the session permits, a panel discussion will be scheduled towards the end of the session.

Note: pending the number and scope of the contributions submitted, the session organisers aim for either a joint review paper on the state-of-the-art of research on issues of scale, or alternatively a special journal issue (e.g. Environmental Modelling & Software).

Organisers: Natasha Herron (Natasha.herron@anu.edu.au)
Carmel Pollino (carmel.pollino@anu.edu.au)

Global climate modelling and regionalisation techniques have been used to make projections about changes in frequency and magnitude of rainfall events and extreme temperatures across the globe. The impacts that these changes have on other environmental variables, such as catchment water balances, biodiversity and fire regimes, have become the focus of further modelling. Results from these models allow us to assess impacts and adaptation strategies to economies, societies and ecological systems. Associated with such assessments are uncertainties, including model uncertainties, inherent variability and lack of knowledge. This session (which will include a mix of presentations and discussion) aims to bring together papers that examine methods and frameworks that are being applied to assess how a changing climate will impact on the health of systems, including ecosystems, urban systems (human population), catchments, rivers, etc. How uncertainties are dealt with will be a key component of discussion.

Organisers: Ted Lefroy (Ted.Lefroy@utas.edu.au),
Tony Jakeman (Tony.Jakeman@anu.edu.au),
Wendy Merritt (Wendy.Merritt@anu.edu.au),
Jenifer Ticehurst (Jenifer.Ticehurst@anu.edu.au),
Liam Gash (Liam.Gash@utas.edu.au),
Andre Zerger (andre.zerger@csiro.au),
Brett Bryan (Brett.Bryan@csiro.au)

Catchment and other Natural Resource Managers are faced with multi-million dollar decisions about where and when to invest for the best overall environmental outcomes. The aim of this session is to bring together scientists and managers to discuss and report on the frameworks, methods and knowledge needed to support decision making for the mix of investment types that advance environmental outcomes. It will include but not be limited to:

• Social science aspects that help us understand stakeholder and landholder decision making, preferences and likely responses to policy instruments
• Landscape process knowledge that can be captured to assess the effects of management and other drivers on vegetation condition, water quantity and quality
• Riverine and estuarine process knowledge that assess effects on ecosystem responses
• Spatial, temporal and other data needs
• Integration of the knowledge bases above for decision support
• Knowledge brokering and participatory processes that identify the needs of managers, engage the interest groups and facilitate adoption.

Organisers: Drs. Gregory Summerell (Gregory.Summerell@environment.nsw.gov.au)
John Gallant, Trevor Dowling and John Wilford

This session covers the broad area of high resolution terrain analysis and geomorphometry with regard to data capture, processing, integration and applications. The session aims to broaden these topics to include new or improved techniques that have lead to wider availability and use of high resolution terrain data, encourages knowledge sharing of experiences, problems and advances in this rapidly growing area of technology and science. The session wishes to build from previous MODSIM sessions on this topic where key areas identified for further development included: 1) the need to develop a library of algorithm techniques to avoid duplication of effort when using finer scaled terrain analysis data, 2) advances in utilising the multiple returns acquired from data acquisition techniques such as LiDAR, 3) developing the most efficient ways to utilise technology for data storage and handling, 4) integrating terrain analysis data at different resolutions to provide different but compatible elevation data for different purposes, and 5) development of tools for terrain analysis quality assessment. Papers that are showing progress on these issues are encouraged. In addition general topics of interest to this session also include: A) new applications of terrain analysis data made possible by higher resolutions, B) new methods to extract information from high resolution terrain data, C) applications in geomorphology, ecology, soil science or hydrology opened up by the new technology, D) any other topic related to the collection, processing and use of high resolution terrain information.