1. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar1Environmental Modelling Principles of Environmental Modelling “The objective of environmental management is to optimize the environment so it better meets the requirements of an ever-increasing human population, or to reduce the environmental impact of human activity.” Hardisty, et al., 1993. Computerised Environmental Modelling. Chichester: Wiley

2. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar2Environmental Modelling Systems Hardisty, et al., 1993. Computerised Environmental Modelling. Chichester: Wiley

3. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar3Environmental Modelling Environmental Systems D.Draper (2001). Our Environment: A Canadian Perspective, Second Edition

4. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar4Environmental Modelling Systems Approach  The process of breaking down highly complex environments into discrete systems so that it can be more easily studied.  Each sub-system will have its own inputs and outputs and interconnected components.  It allows us to focus on that which is of direct interest; everything else is ignored.

5. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar5Environmental Modelling Assumptions 1.It is actually possible to subdivide the real world into discrete, contained, functioning systems. 2.It is possible to determine the various inputs and outputs and interrelationships between system components.

6. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar6Environmental Modelling Environmental Systems Analysis 1.Lexical Phase 2.Parsing Phase 3.Modelling Phase 4.Analysis Phase

7. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar7Environmental Modelling Environmental Systems Analysis 1.Lexical Phase  Define system boundaries.  Choose system components.  state variables  Estimate the values (states) of the state variables. damped explosive periodic unsystematic

8. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar8Environmental Modelling Environmental Systems Analysis 1.Lexical Phase 2.Parsing Phase  Define the relationships between the state variables.  Deterministic  Stochastic

9. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar9Environmental Modelling Environmental Systems Analysis 1.Lexical Phase 2.Parsing Phase 3.Modelling Phase  Model construction  Requires a description of how changes in the controlling variables affect the state variables  Operationalizing (i.e. running) the model

10. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar10Environmental Modelling Environmental Systems Analysis 1.Lexical Phase 2.Parsing Phase 3.Modelling Phase 4.Analysis Phase  Model validation  If the model results compare poorly with observed data, the model may need to be re-designed and steps 2 and 3 repeated.

11. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar11Environmental Modelling Classification of Environmental Systems  Morphological  Least complex type  Emphasis is placed on the relationships between state variables and their relative strengths  Useful for determining how one system state variable affects the others Hardisty, et al., 1993. Computerised Environmental Modelling. Chichester: Wiley

12. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar12Environmental Modelling Classification of Environmental Systems  Cascading  System components are linked by flows of mass and/or energy Hardisty, et al., 1993. Computerised Environmental Modelling. Chichester: Wiley

13. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar13Environmental Modelling Classification of Environmental Systems  Process-Response  Includes parts of morphological and cascading systems Hardisty, et al., 1993. Computerised Environmental Modelling. Chichester: Wiley

14. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar14Environmental Modelling Classification of Environmental Systems  Control  Similar to process-response systems but include a human controlling factor. Hardisty, et al., 1993. Computerised Environmental Modelling. Chichester: Wiley

15. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar15Environmental Modelling Environmental Systems  One of the problems with traditional environmental monitoring is that there is a tendency to merely illustrate what has happened in the past.  With an environmental systems approach, it is also possible to describe what the future may hold in store.

16. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar16Environmental Modelling Why Model?  A model represents a simplification of reality.  The intention is to retain the significant features and relationships of reality.  All models are subjective.  The modeller chooses which real-world elements should be included as well as how they are represented.  Models are used to describe, explore, and analyze how a system works; and to test predictive “what if?” scenarios.

17. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar17Environmental Modelling Types of Models 1.Natural Analogue System a)Historical analogue b)Spatial analogue 2.Physical System a)Hardware model i. Scale ii. Analogue b)Mathematical i. Deterministic ii. Stochastic c)Experimental Design 3.General System a)Synthetic b)Partial c)Black box

18. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar18Environmental Modelling Types of Mathematical Models Hardisty, et al., 1993. Computerised Environmental Modelling. Chichester: Wiley

19. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar19Environmental Modelling A Deterministic Model

20. Geog 409: Advanced Spatial Analysis & Modelling © J.M. Piwowar20Environmental Modelling A Stochastic Model