| dc.description.abstract | The meandering stream has been well studied in temperate environments but the
same level of research has not been achieved for meandering streams in tropical areas.
The overall objective of this research was to gain an increased understanding of
meandering planform dynamics in humid tropical rivers. The objective was pursued by
examining the rate of change of channel pattern and results indicate that migration rate
and the range of radius of curvature to width ratio where maximum migration occurs is
similar to those reported for humid temperate rivers. In summary, as regards to these
aspects, the results suggest that the representative humid tropical river is no more
dynamic than its temperate counterparts.
A second objective was to document the response and recovery of a humid
tropical river system to an extreme flood event. As a result, the trend of shorter recovery
times following a major perturbation was demonstrated, and suggests that in the long
term, a large flood such as a 100-year event apparently plays a relatively minor role as a
formative event in shaping the overall humid tropical landscape.
A third objective was to develop an empirical model for predicting bend
migration rates in humid tropical rivers, resulting in empirical relationships that indicate
that meander migration has a high degree of correlation with the number of bankfull
discharge events under all scenarios, and that model correlation can be enhanced when
the silt-clay composition of the banks, and the radius of curvature to width ratio are
included as independent variables. The resulting equations were tested to predict
maximum meander migration distance, and predictions produced very satisfactory
results.
In addition to increasing basic understanding of meander processes in tropical
areas and for developing fluvial geomorphological theory, the results of this research
have potentially important benefits to society. Because property and structures are often
threatened by channel movement, there is a need for improved predictive capability of
deformation of stream channels, and the results can therefore be useful to engineers and
other professionals in delineating channel hazard zones. | en |
