LEON, J. G., Univ Nacional de Columbia, Sede Palmira, Colombia, jgleonh@palmira.unal.edu.co
SEYLER, F. ., IRD, Brazilia, Brazil, frederique.seyler@ird.fr
BONNET, M. P., IRD, Brazilia, Brazil, bonnet@ird.fr
CALMANT, S. ., IRD, Brazilia, Brazil, stephane.calmant@ird.fr

RATING CURVE IN THE UNGAUGED CAQUETA BASIN COMBINING ALTIMETRY-DERIVED WATER STAGES AND DISCHARGE PROPAGATED FROM REMOTE STATIONS

Provide distributed discharges is a major task of hydrological monitoring. However, fewer and fewer in-situ measurements are collected each year wherever over the world. From the last two years, virtual gauge stations have been proposed to increase the density of hydrological monitoring network in Amazon basin (Leon et al. 2006). In spatial hydrology a virtual station is considered as any crossing of water body surface (i.e., large rivers) by radar altimeter satellite Tracks. We present rating curves obtained for thirteen virtual gauge stations at the main stream of Caqueta Basin, a poorly gauged basin in the Colombian Amazon basin. Water stages have been derived from satellite altimetry (T/P and ENVISAT). Discharges were propagated at the location of the satellite tracks from remote gauging stations using a 1D Muskingum-Cunge model. Validation has been conducted by comparing the results with stages and discharges measured at five in-situ gauges available on the Caqueta main stream. Outflows errors range from 10% to 20% between the upper basin and the lower basin respectively. The method proposed by Leon et al. (2006) to deduce zero flow depth at virtual stations was applied and its allows to find mean absolute differences less than 1.1 m between estimated and measured zero flow depth. Finally, a 1,2 x 10-4 m.m-1 mean bottom slope has been obtained for the 730 km long reach of the considered stream.

Poster presentation

Presentation is given by student: No
Session #:006
Date: 03-03-2008
Time: 17:30 - 19:30