4-D Nonlinear
-Dynamical Fluvial Modeling Using
Deterministic Equations and Fuzzy Logic
EDINGTON, DWAINE H. and TIMOTHY A. CROSS
A four-dimensional nonlinear
, dynamical forward model of fluvial
stratigraphy, FLUVSIM, has been developed. This program incorporates the
following features: 1) The program is deterministic in that it employs
empirically developed geomorphic and stratigraphic process-response
relationships. It does not use randomly generated processes or events in the
simulations. 2) It simulates sediment accumulation and erosion at the channel
belt-floodplain scale. The interconnected fluvial, floodplain, and lake
environments are a
nonlinear
dynamical system that can achieve self-organized
critical states. The model incorporates the concepts of process-response
feedbacks, thresholds, and memory. 3) It uses fuzzy logic to determine where,
how much, and what kind of sediment to deposit and erode.
The model uses fuzzy logic to reproduce complex process-response relationships normally found in stratigraphic systems. A fuzzy system consisting of fuzzy sets and fuzzy rules rather than a set of mathematical equations controls erosion and deposition. Implementing the fuzzy logic system involves two steps: (1) Creating fuzzy sets within each of these domains, and (2) writing fuzzy rules that operate on these sets. The program gives the user full control on implementing the fuzzy logic system.