Complex Systems Analysis of Water Quality Dynamics; The Feedback Systems Structure

摘要

The objective of the research was to identify and demonstrate how the management and control of water quality in a region is influenced by prevailing social, political and economic conditions and to illustrate how these prevailing conditions and attitudes interrelate in an information feedback and control system to produce traditional modes of system response. A generalized model was tested under a wide range of policies and parameters to illustrate system response and sensitivity to changes. Industrial dynamics was used to model the multi-loop, non-linear feedback system, and the DYNAMO simulation language was used to program the model for digital computer simulation, testing, and experimentation. The modeling phase isolated system variables and identified their relative magnitudes, periods and phasing in historically polluted watersheds. Different policies and parameters were tested in a refined model to determine their effect on total system response. Water quality management and control was found to be deeply embedded in a complex, information feedback system involving social, political and economic pressures and forces. The complex system response was found to be insensitive to many parameter changes and unintuitive in behavior. (WRSIC abstract)