Developing Understanding of
Ecological Economic Systems
Thomas Maxwell
Robert Costanza
University of Maryland
Institute for Ecological Economics
Motivation
• Unbridled expansion of human enterprise.
• Depletion of natural life support systems.
• Resource depletion -> global tensions.
• Interacting complex systems.
• Tremendous uncertainty.
• Potentially disastrous consequences.
Institute for Ecological Economics
Integrated Problem Solving
• Vision
– State of the world.
– Possible future worlds (postitive & negative).
• What to tweak?
– Expected outcomes of policy adjustments.
• Methodology
– Hard problem science.
– Adaptive management.
Institute for Ecological Economics
Science in Service of Society
• Comprehensive systems approach
– Conceptual pluralism
– Problem driver
– Multiscale
– Integrated modeling
• Links with policy
– Modeling as consensus building tool
– Communicating uncertainty
Institute for Ecological Economics
Collaborative (Visible) Modeling
• Realistic models require multiple teams
• Modelers typically not computer scientists
• Stake holders must be included
• Communication to a wide audience
Institute for Ecological Economics
Three Stage Modeling Process
• Scoping models
– Consensus building
• Research models
– Understanding dynamics
• Management models
– Exploring scenarios
Institute for Ecological Economics
Modeling Collaboratory
• Constructivist learning.
• Paradigm expansion.
– (narrow,linear,static) ->
– (broad,nonlinear,dynamic)
•
•
•
•
Conflict resolution.
Consensus building.
Collective decision making.
Develop management scenarios.
Institute for Ecological Economics
Supporting Collaborative Modeling
• Graphical modeling tools
• Modular model development
• Transparent high performance computing
• Integrated data access
• Integrated visualization
• Variety of formalisms and frames
Institute for Ecological Economics
Graphical Modeling
•Model viewed and manipulated graphically.
•Opens model development to non-programmers.
•Facilitates rapid development of models.
•Enforces modeling standards.
•Facilitates collaboration in model development.
•Graphical representation serves as a blackboard.
Institute for Ecological Economics
STELLA Model
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Spatial
Modeling
Framework
Institute for Ecological Economics
Environmental Modeling Workbench
Spatial Modeling Environment
Inputs to multiple
models
Coupled
Bio-Hydro
Simulation
Integrated wireless
Sensor web
Environmental Hydrology Applications Team
Institute for Ecological Economics
Two types of modules
• Ecological Modules
– No general theory.
– Primary focus on modeling.
– Examples:
• Macrophytes, Epiphytes, Consumers, Phytoplankton
– Modules developed in Stella/SME.
• Physical Modules
– Theory well known (e.g. Navier Stokes).
– Primary focus on computation.
– Examples:
• hydrodynamics, atmospheric dynamics.
– Modules developed externally and linked to SME.
Institute for Ecological Economics
Spatial Modeling Environment
• Collaborative Spatial Modeling Workbench
• Includes integrated support for:
–Icon-based unit module development
–Module archiving and reuse
–Integration of multiple spatial representations
–Distributed computing
–Web-based modeling & simulation
•Configuration, control, and visualization of remote simulations.
–Data access and visualization
–Real-time links to other apps (e.g. Swarm).
Institute for Ecological Economics
Spatial Modeling Environment
Module
Repository
Module
Builder
Simulation
Driver
Unit model
Graphical
modeling
Spatial model
STELLA
Code
Generator
PowerSim
SME Module
Editor
HPC
Module
Constructor
SMML Module Library
Institute for Ecological Economics
Java
Portal
Module Specification Language
•Declarative
•Modular
•Fully visible structure & dynamics
•Supports encapsulation and specialization
•Separate universal specs / site-specific configs
•Platform and operating system independent
•Facilitates extensive simulation services
Institute for Ecological Economics
Simulation Module Markup Language
• XML-Based Declarative Language
• Simulation Module Specification
• Major Classes:
–Module: Reusable component.
–Variable: Simulation atomic object.
–Action: Performs computation or data IO.
–Event: Orders the execution of Actions.
–Frame: Defines a spatial topology.
Institute for Ecological Economics
SMML Example
<atom name="CONS_BIOM" id="CONS_BIOM" status="private" type="state" >
<port type="input" name="CONS_INGEST" />
<port type="input" name="CONS_EGEST" />
<port type="input" name="CONS_MORT_BIOM" />
<port type="input" name="CONS_RESPIRATION" />
<dynamic event="integrate" type="code" >
<code>
( ( ( CONS_INGEST-CONS_EGEST )-CONS_MORT_BIOM ) ) CONS_RESPIRATIO
</code>
</dynamic>
<port type="input" name="P1_CONS_IC" />
<port type="input" name="CELL_SIZE" />
<dynamic event="init" type="code" >
<doc>
CARBON BIOMASS OF AN AGGREGATED CONSUMER. (KGC).
CONSUMERS EXCLUDE THE MICRO ORGANISMS WHICH ARE
ACCOUNTED FOR IN THE RESPIRATION FLUXES
</doc>
<code>
( ( P1_CONS_IC*0.001 )*CELL_SIZE )
</code>
</dynamic>
</atom>
Institute for Ecological Economics
SMML Example
<?xml version="1.0"?>
<!DOCTYPE compound SYSTEM "http://iee.umces.edu/SME/dtd/smml.dtd">
<compound id="PLMD_module" name="PLMD_module" >
<compound id="CONSUMERS_module" name="CONSUMERS_module"
location="CONSUMERS_module.xml" >
<port type="output" name="CONS_EGEST" />
<port type="output" name="CONS_MORT_BIOM" />
<port type="output" name="CI_DETR" />
...
</compound>
...
<link name="c__0"
<link name="c__1"
<link name="c__2"
origin = "GLOBALS_module.CELL_SIZE"
destination = "CONSUMERS_module.CELL_SIZE" />
origin = "DETRITUS_module.DET_AVAIL"
destination = "CONSUMERS_module.DET_AVAIL" />
origin = "DOM_module.DOM_C_AVAIL"
destination = "CONSUMERS_module.DOM_C_AVAIL" />
</compound>
Institute for Ecological Economics
Typical State Variables
• Examples of some typical state variables:
– (Dissolved Inorganic) Nitrogen, Phosphorus
– Water (Saturated, Unsaturated, Surface, Snow)
– Detritus
– Macrophyte (Non)Photosynthetic Biomass
– Consumers
– Deposited Organic Matter
– Phytoplankton
– Epiphytes
Institute for Ecological Economics
Agent Based Modeling in SME
• Swarm agents can populate SME landscapes.
• SME-Swarm integration:
– http://iee.umces.edu/~villa/swarmsme
• Swarm classes serve as wrappers for:
– SME model.
– SME grid layers.
– SME spatial variables.
• Two-way remote data transfer.
• Built on SNI simulation server architecture:
– http://iee.umces.edu/~villa/sni
Institute for Ecological Economics
Multi-Grid Library
•Integrates multiple spatial representations
• Implements space in SME
• Major Components include:
–Cell: Spatially referenced area (or volume) element.
–Grid: Distributed set of Cells + links.
–Frame: Hierarchy of distributed Grids.
–Link: Connection between Cells.
•Intra-Grid: spatial contiguity.
•Inter-grid: scaling relations or mappings.
–Activation Layer: Subset of Cells in a Frame.
–Coverage: Mapping:: Activation Layer -> floats.
Institute for Ecological Economics
Distributed Processing
Spatial grid
partitioned over processors
Highly parallel application
Recursive N-section:
excellent load balancing
Fully transparent to user
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Model Calibration toolkit
• Built on MPE toolkit:
– http://iee.umces.edu/~villa/svp/
• Calculate performance measure (MPE)
– Estimate of match between model & system.
– Weighted sum of tests (Bounds, Theil, Freq, etc).
• Search parameter space to maximize MPE.
– Evolutionary and gradient searches.
• Params, tests, & searches configured in SME.
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SME Java Portal
•Desktop access to remote supercomputing resources
•Web-enabled ( using java servlets )
•Grid enabled ( using globus gram utility )
•Java applet <-> Java servlet <-> C++ apps
•Portal interfaces include:
–Workspace management
–Module development
–Model configuration
–Simulation initialization, control, & visualization
Institute for Ecological Economics
WorkSpace Manager
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Configuration
Manager
Documentation Panel
Documentation of
selected command
Model Panel
Hierarchical View of model objects
Associated commands as boxes
Command Panel
Structure of selected command
Property Panel
Command Arguments
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Parameter
Editor
Edit Simulation
Parameters
Spreadsheet format
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Simulation
Control
Control Execution
View Model Structure
Trace Dependencies
View Model Equations
Configure Visualization
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ViewServer Control Panel
Associates DataSets
with Viewers
Creates Viewers
Manages DataSets
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2D Animation Viewer
2D Animation Control
Dynamic and manual rescaling
ColorMap editor
Data viewer (point/spreadsheet)
Export as GIF or JPG
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3D Animation Viewer
Dynamic Landscapes
Variable1 -> Altitude
Variable2 -> Color
Mouse controlled
navigation
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Image Spreadsheet
Simultaneous display of variables at multiple timesteps
Useful for time series comparisons
Configure: start time, time step, magnification, scaling, etc.
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Numerical Spreadsheet
View spatial data
Attach to vis panels
Follows animation
Export to Stat
packages.
Institute for Ecological Economics
Chesapeake Bay Model
• Links
components:
– Circulation (OM3)
– Ecology (SME)
– Atmospheric
coupling
Environmental Hydrology Applications Team
Institute for Ecological Economics
Collaborative Virtual Environment
Chesapeake Bay data in CVE with Cave5D/Virtual Director
Environmental Hydrology Applications Team
Institute for Ecological Economics
Example Applications
• Everglades Landscape Model
– http://www.sfwmd.gov/org/erd/esr/elm/intro/welcome.htm
• Patuxent Landscape Model
– http://iee.umces.edu/PLM
• Baltimore Ecosystem Study
– http://baltimore.umbc.edu/lter
• Illinois TES Models
– http://blizzard.gis.uiuc.edu/
Institute for Ecological Economics
Environmental Hydrology
Environmental Hydrology Applications Team
Institute for Ecological Economics
SME Distribution
The SME home page:
http://iee.umces.edu/SME3
Includes:
– Overview.
– Technical documentation.
– Publications.
– Source code (C++ and java).
– Links
Institute for Ecological Economics