Page 32 - GENERACION Y TRANSPORTE DE SEDIMENTOS

32 PEA BERMEJO

the Bermejo-Bermejito watershed. observed, presumably generated by dams built on
Regarding the control measures of the process- the Parana River in Brazil. These circumstances gen-
es associated with sediments in the Lower Basin, erate that the sediments delivered by the Bermejo
the picture is generally similar to the Upper Basin, River to the Paraná River, have a greater weight in
with the particularity of the remarkable presence the total sediments transported by this river, being
of meanders of high morphological activity. the current rate for the Bermejo of about 80-85%
of the total.
The Bermejo River and del Plata Basin The influence of sediment load of the Bermejo
River in the Paraguay-Paraná-de la Plata System
One objective of the studies conducted within was analyzed, making solid contributions balances
the framework of the SAP Bermejo was to examine in the system from the basic information available
the influence of sediment load of the Bermejo River in the stations of the network. We may say that,
in the Paraguay-Paraná-de la Plata System. considering the station Itatí as representative of
It has been said that the most relevant feature the conditions of the Paraná River upstream from
of the Bermejo River Basin is the large amount of the confluence with the Paraguay, and Puerto Pilco-
sediment in it, which is among the highest rates of mayo in Paraguay, showed that on average values,
sediment produced per unit of area in the world. the Bermejo provides 81% of the total solid load of
Past studies record that the contribution of sus- the Paraná River (tunnel section) and the Paraguay
pended solids of the Bermejo River to such solid river contributes 6%.
load in the river Paraná (in Corrientes) constitutes Additionally, an analysis of the balance of ma-
70% of the total, considering the full range of re- terial carried in suspension through the Bermejo
cords available and increasing the percentage, if system from solid flows was made. In this case, it
you look in recent years. is difficult to give definitive and realistic values of
Of the total above, approximately 80% of the solid contributions for the main tributaries of the
suspended load supplied to the Upper Bermejo Upper Basin, especially due to the different length
in Junta de San Francisco comes from the Upper of available records, and its non-simultaneousness.
Bermejo sub-basin and the remaining 20% from However, several approaches were made from the
San Francisco sub-basin. Considering the number collection of historical data.
of solid gauging in Pozo Sarmiento and Caimanci- As conclusion on this issue, it can be said that
to, a suspended transport of 70,508,100 tons per tests carried out confirmed the validity of the ratios
year (79%) was obtained for Pozo Sarmiento, and, presented for the contributions of the tributaries
18,901,200 tons per year (21%) for Caimancito, to- of the Upper Bermejo River. It should be noted that
taling 89,409,300 tons annually. these proportions and, to a much greater extent,
It should be noted that, approximately in the last the amounts of sediment involved strongly depend
30 years, a decline of the wash load in the Paraná is on the period of study. The Iruya river is confirmed