Systems Engineering of Natural Resources under Changing Physical Conditions: State of the Art in Systems Modeling

Abstract

Decisions under physically changing input, such as hydrometeorological input under global climate change, must be made under incomplete and uncertain information about the consequences of this change. To make these decisions, we argue that good system models are necessary. First, linear model have much to offer because of their well studied characteristics, which can help before trying to understand how complex behavior may occur on simple realistic models that are most of the time non linear systems. Second, changing a physical forcing function, even slightly, may induce radical changes of system behavior: it is thus imperative to identify the critical points of systems that can exhibit such bifurcations. Available algebraic system tools which have been designed for this task are briefly reviewed. Finally the difficulty in establishing a distinction between random and chaotic behavior is pointed out.