RIVER-FLOODPLAIN GEOMORPHOLOGY AND CONNECTIVITY OF THE LOWER PARAGUAY HYDROSYSTEM

EDMUNDO C. DRAGO, ALDO R. PAIRA, KARL M. WANTZEN

Ecohydrology & Hydrobiology

UNESCO (Venice, Italy) & International Centre for Ecology-Warsaw, Institute of Freswater Biology-Cracow. Polish Academy of Sciences.

Lugar: Warsaw; Año: 2007 vol. 8

1642-3593

The Paraguay River is the most important tributary of the Paraná River hydrosystem. Despite several studies resulting from the proposed navigation project known as the Paraguay-Paraná Hidrovía, little is known about their aquatic environments and biota. Here, we report the geomorphological characteristics and the hydrological connectivity of the Lower Paraguay main channel and its fringing floodplain, a 350 km segment between Asunción (Paraguay) and the confluence with the Paraná River. We suggest that the dynamics of the river-floodplain morphology, the large-scale longitudinal and lateral hydrological connections, the type and degree of connection between lotic and lentic environments and the substrate type are the key factors driving the changes of this seasonally inundated floodplain and its water bodies. Thus, the understanding the floodplain ontogeny along with the ageing and rejuvenation processes derived from the fluvial dynamics, contribute to enhance the comprehension of the complex relationships between the riverine environments and their responses to the natural and man-made changes. Keywords: Large river, geomorphology, hydrological connectivity, floodplain ontogeny, hydro-functional classification of lakes.