7-Day SELES Course Day 4

From SELESwiki

Back to Course Index

Contents:

Landscape Event Contexts

Spatio-temporal contexts

• landscape change arises as the result of feedback between system state and definable processes or entities
• as agents of landscape change, processes react to and modify the landscape state in spatio-temporal contexts
• a spatio-temporal context is the set of information (i.e. state variables) available at a particular time and place
• contexts provide a general hierarchical framework for describing landscape dynamics
• SELES is a language for:
  • creating a spatio-temporal state-space
  • defining behaviours to navigate through contexts in this state-space, and
  • specifying state changes in those contexts
• by managing contexts appropriately, models of various forms can be created, including:
  • cellular automata
  • individual-based models (IBMs)
  • spatio-temporal Markov chains

Navigating Contexts via Landscape Events

Event Behaviour

Hierarchical Dynamic State

Context Hierarchy

Context Hierarchy: Available Variables

Context Hierarchy: Containment

Spatio-Temporal Contexts

Landscape Event Properties

• Initial State
• Return Time
• Event Location
• Number of Clusters
• Probability of Initiation
• Transitions
• Spread Rate
• Spread Location
• Probability of Spread
• Number of Spread Recipients

Event Initiation

Event Spread

Spatio-Temporal Contexts

NUMCLUSTERS: Replacement

• Default: without replacement
• Option:
  • NUMCLUSTERS WITH REPLACEMENT

PROBINIT: SORTED

• Default: probabilistic
• Option:
  • PROBINIT ORDERED
  • Process cells in decreasing order according to value of PROBINIT

PROBINIT: RANDOM

• Default: process from bottom left to top right or vice versa (i.e. don’t count on it)
• Option:
  • PROBINIT RANDOM
  • Process cells in random order

PROBINIT: RECOMPUTE

• Default: computed once at start of initiation
• Option:
  • PROBINIT RECOMPUTE
  • Indicates that probabilities for unprocessed cells may be recomputed by a call to RECOMPUTE expression