The detection of catastrophic discontinuities in the acid-phosphorus relationship (A complex systems model)

Recognising the continual emergence of sudden catastrophic environmental changes resulting from the complex interactions of apparently disparate phenomena, and utilising an existing spatio-temporal model of two such phenomena applied to the Rutland Water Catchment, this paper presents a complex systems approach to the modelling of such environmental catastrophes which may be described as Chemical Time Bomb (CTB) phenomena. This is achieved through the definition and spatial observation of a catastrophe indicator which indicates both the proximity and magnitude of catastrophe arising from the non-linear and discontinuous acid-phosphorus relationship within the soil domain. Definition of this indicator facilitates the assessment of the vulnerability of a river catchment to potential propagation of this CTB whereby the soil suddenly changes from being a sink to a source of phosphates; long-term accumulations of phosphate in the soil being released as a consequence of soil acidification in the short-term. This complex systems approach - hinged upon the concept of a catastrophe indicator - highlights the non-linearities and discontinuities between apparently disparate phenomena which are 'competing' for a common resource, with the heuristic value of the indicator arising from the ability to understand more clearly the dynamics of these inter-relationships through examination of the temporal changes in the dynamic spatial landscapes which emerge from simulations.