Comparative analysis of rating curve and ADP estimates of instantaneous water discharge through estuaries in two contrasting Brazilian rivers
Article first published online: 1 FEB 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Volume 25, Issue 14, pages 2188–2201, 1 July 2011
How to Cite
da Silva Dias, F. J., Lacerda, L. D., Marins, R. V. and de Paula, F. C. F. (2011), Comparative analysis of rating curve and ADP estimates of instantaneous water discharge through estuaries in two contrasting Brazilian rivers. Hydrol. Process., 25: 2188–2201. doi: 10.1002/hyp.7972
- Issue published online: 5 JUL 2011
- Article first published online: 1 FEB 2011
- Manuscript Accepted: 2 DEC 2010
- Manuscript Received: 30 APR 2010
- tropical river;
- river discharge;
- rating curve;
This work quantifies, using ADP and rating curve techniques, the instantaneous outflows at estuarine interfaces: higher to middle estuary and middle to lower estuary, in two medium-sized watersheds (72 000 and 66 000 km2 of area, respectively), the Jaguaribe and Contas Rivers located in the northeastern (semi-arid) and eastern (tropical humid) Brazilian coasts, respectively. Results from ADP showed that the net water balances show the Contas River as a net water exporter, whereas the Jaguaribe River Estuary is a net water importer. At the Jaguaribe Estuary, water retention during flood tide contributes to 58% of the total volume transferred during the ebb tide from the middle to lower estuary. However, 42% of the total water volume (452 m3 s−1) that entered during flood tide is retained in the middle estuary. In the Contas River, 90% of the total water is retained during the flood tide contributing to the volume transported in the ebb tide from the middle to the lower estuary. Outflows obtained with the rating curve method for the Contas and Jaguaribe Rivers were uniform through time due to river flow normalization by dams in both basins. Estimated outflows with this method are about 65% (Contas) and 95% (Jaguaribe) lower compared to outflows obtained with ADP. This suggests that the outflows obtained with the rating curve method underestimate the net water balance in both systems, particularly in the Jaguaribe River under a semi-arid climate. This underestimation is somewhat decreased due to wetter conditions in the Contas River basin. Copyright © 2011 John Wiley & Sons, Ltd.