1st International Congress on Environmental Modelling and Software - Lugano, Switzerland - June 2002
Keywords
multimedia modelling, model evaluation, parallel distributed processing, supercomputer, java
Start Date
1-7-2002 12:00 AM
Abstract
Elucidating uncertainty and sensitivity structures in environmental models can be a difficult task, even for low-order, single-medium constructs driven by a unique set of site-specific data. Quantitative assessment of integrated, multimedia models that simulate hundreds of sites, spanning multiple geographical and ecological regions, will ultimately require a comparative approach using several techniques, coupled with sufficient computational power. The Framework for Risk Analysis in Multimedia Environmental Systems - Multimedia, Multipathway, and Multireceptor Risk Assessment (FRAMES-3MRA) is an important software model being developed by the United States Environmental Protection Agency for use in risk assessment of hazardous waste management facilities. The 3MRA modelling system includes a set of 17 science modules that collectively simulate release, fate and transport, exposure, and risk associated with hazardous contaminants disposed of in various land-based waste management units. The 3MRA model encompasses over 700 variables, 185 of which are explicitly stochastic. Design of SuperMUSE, a 125 GHz PC-based, Windows-based Supercomputer for Model Uncertainty and Sensitivity Evaluation is described. Developed for 3MRA and extendable to other computer models, an accompanying platform-independent, Java-based parallel processing software toolset is also discussed. For 3MRA, comparison of stand-alone PC versus SuperMUSE simulation executions showed a distributed computing overhead of only 0.57 seconds/simulation, a relative cost increase of 0.7% over average model runtime. Parallel computing software tools represent a critical aspect of exploiting the capabilities of such systems. Fairly small, easy to write, and well suited for this application, the Java toolset developed here readily handled machine and job management tasks over the distributed system. SuperMUSE can complete over 2.5 million 3MRA model simulations per month.
Investigating Uncertainty and Sensitivity in Integrated, Multimedia Environmental Models: Tools for 3MRA
Elucidating uncertainty and sensitivity structures in environmental models can be a difficult task, even for low-order, single-medium constructs driven by a unique set of site-specific data. Quantitative assessment of integrated, multimedia models that simulate hundreds of sites, spanning multiple geographical and ecological regions, will ultimately require a comparative approach using several techniques, coupled with sufficient computational power. The Framework for Risk Analysis in Multimedia Environmental Systems - Multimedia, Multipathway, and Multireceptor Risk Assessment (FRAMES-3MRA) is an important software model being developed by the United States Environmental Protection Agency for use in risk assessment of hazardous waste management facilities. The 3MRA modelling system includes a set of 17 science modules that collectively simulate release, fate and transport, exposure, and risk associated with hazardous contaminants disposed of in various land-based waste management units. The 3MRA model encompasses over 700 variables, 185 of which are explicitly stochastic. Design of SuperMUSE, a 125 GHz PC-based, Windows-based Supercomputer for Model Uncertainty and Sensitivity Evaluation is described. Developed for 3MRA and extendable to other computer models, an accompanying platform-independent, Java-based parallel processing software toolset is also discussed. For 3MRA, comparison of stand-alone PC versus SuperMUSE simulation executions showed a distributed computing overhead of only 0.57 seconds/simulation, a relative cost increase of 0.7% over average model runtime. Parallel computing software tools represent a critical aspect of exploiting the capabilities of such systems. Fairly small, easy to write, and well suited for this application, the Java toolset developed here readily handled machine and job management tasks over the distributed system. SuperMUSE can complete over 2.5 million 3MRA model simulations per month.
