Page 29 - GENERACION Y TRANSPORTE DE SEDIMENTOS

Generación y Transporte de Sedimentos 29

tance, both from the standpoint of understand- Basin, either structural or non-structural.
ing the phenomenon itself and the development The methodology developed within the frame-
of design methodologies of works subject to the work of the SAP Bermejo for sediment production
action of this type of flows, resulting generally, by superficial erosion in mountain river basins, was
in solicitations of magnitudes higher than those succesfuly applied in the Upper Basin of the Ber-
for flows of sediment-laden water. Beyond basic mejo River, with results validated with field data,
research on the topic of dense flows, the river and replicated succesfully in other mountain zones
hydraulics aimed at practical applications in the of South America, including the northwest of Ar-
field of engineering related to this phenomenon, gentina, the Patagonia in Argentina, and the Upper
which desperately need the quantification of pro- Pilcomayo Basin in Bolivia.
cesses. Thus, the developments that are based The types of erosion control works in beds of
on known physics of the problem, analyzing the the Upper Basin are very similar to those of the
forces at play, and considering equations to solve entire northwestern Argentina, and are illustrated
the dynamics of the problem, are the most suit- with photographs in the book. There you can see
able. Although the application of the models aris- that the works are varied both in terms of prob-
ing from these methods is still difficult, having to lems to solve as well as for the proposed types.
recourse to empiricism for the resolution of prac- Thus, we have bank protection works by breakwa-
tical cases, knowledge of the qualitative behavior ters and other longitudinal works such as cover-
of dense flows obtained from its development, ings and marginal walls, and cross-bed works to
is an essential base against a specific engineer- stabilize river beds with high sediment transport
ing problem which needs to be solved as in the rate, as in the case of Colanzuli-Iruya, as well as to
Bermejo River. A practical application in the area control streams.
of the river Colanzulí-Iruya was developed, rang- The case of torrent control works in the Upper
ing from empirical formulas to numerical models Basin was treated in detail, also on the Colanzulí-
developed for this type of flows. Iruya Basin. A methodology for implementing this
Within the framework of the Upper Basin, it is type of work is presented, based on morphologi-
noteworthy the solid transport in mountain riv- cal model of mountain rivers and considerations on
ers; a topic analyzed in the SAP Bermejo project. debris flows.
The need to assess the solid transport in extended At the time of assessing the sediment control
particle size rivers such as mountain rivers led to works in order to significantly reduce the amount
the development of a specific program within the of sediments contributed to the system, it should
framework of the studies: ANDES Program de- be noted that feasible handling measures in the
veloped to study the morphological evolution of Upper Basin of the Bermejo that substantially
mountain rivers. This model was used for the proj- affected the amount of sediments were not ob-
ect of different erosion control works in the Upper served. Accordingly, it can be said that, under