Page 31 - GENERACION Y TRANSPORTE DE SEDIMENTOS

Generación y Transporte de Sedimentos 31

The basis of the concepts described earlier al- on image processing necessary for the implemen-
lowed tackling the study of the fluviomorphological tation and use of the model, were carried out. The
dynamics of the Lower Bermejo River. In this con- model used was the RVR Meander, developed by
text, a one-dimensional morphological model was Dr. Marcelo Garcia and his team, to characterize
implemented, using the MIKE 11 model, software and analyze the migration of meanders in rivers.
developed by the Danish Hydraulic Institute (DHI). Said studies verified the existence of a phenom-
With the implementation of this model, it was enon of stacking of meanders upstream of the
confirmed that both the erosion of the bed during bridge, generated by restriction embodied therein.
peak flood, and the depositions in the same sec- Downstream, the process is the other way round: in
tions in areas of recession of hydrographs, are well a large section of the river, side migrations are not
explained using equations that calculate the total observed. With the implementation of the model,
transport of sand. known situations of evolution of meanders were
The model could be validated for different flood correctly predicted despite the limitation of the
and levels of bed scenarios, allowing highlighting model that cannot resolve cuts of meanders.
the importance of the floods of the river, also as a However, it is a predictive tool to study trends
natural phenomenon. in rivers with similar characteristics to those of the
The fluviomorphological study of the Lower Ber- lower Bermejo.
mejo River was completed with the analysis of plant The developments presented are relevant to
morphology of the river and its impact on road in- characterize the type of studied rivers and for the
frastructure. Movements in lower Bermejo River consideration of morphological processes, which
plant are famous worldwide for the development develop in the presence of cross structures to the
of its meanders. This complex three-dimensional current in rivers with meanders.
physical phenomenon shows a certain degree of As noted earlier, the issue of flooding by the
difficulty in trying to develop a mathematical tool overflow of the main channel of the Lower Bermejo
to characterize and predict these meanders, a task River is recurrent in the area. An analysis of flow
that was undertaken given the importance of the determination of overflow in the Lower Basin was
development of meanders in relation to the involve- performed. The important implications associated
ment of roads, rail, productive and social develop- with the floods, which occur to a greater or lesser
ment in the Basin. Specifically, a particular model of extent in the river flood periods, makes necessary
evolution of meanders to the plant morphology of to study the characteristics of them. The analysis
the Bermejo and its impact on infrastructure was made includes the reason why incoming flows from
used, with direct application on the Puerto Lavalle the Upper Basin may cause overflows in the Lower
bridge, systematically affected by erosion process- Basin, and overflow volumes were quantified from
es on both sides. historical records.
Geomorphological and hydraulic studies based The area with the highest volumes of overflow is