Water Quality and Sediment Behaviour of the Future: Predictions for the 21st Century Proceedings of Symposium HS2005 at IUGG2007, Perugia, July 2007).  IAHS Publ. 314, 2007, 3-10

 

Suspended sediment yields in the Amazon basin of Peru: a first estimation

 

Jean Loup GUYOT1, Hector BAZAN2, Pascal FRAIZY1, Juan Julio ORDONEZ3, ELISA ARMIJOS4 & ALAIN LARAQUE5

1  IRD – LMTG (Institut de Recherche pour le Développement – Laboratoire des Mécanismes de Transfert en Géologie), Casilla 18-1209, Lima 18, Peru

jean-loup.guyot@ird.fr

2 UNALM – FIA (Universidad Nacional Agraria La Molina – Facultad de Ingeniería Agrícola), Avenida La Molina s/n, Lima 12, Peru

3 SENAMHI – DGH (Servicio Nacional de Meteorología e Hidrología – Dirección General de Hidrología), Casilla 11-1308, Lima 11, Peru

4 INAMHI, Iñaquito700 y Corea, Quito, Ecuador

5 IRD – OBHI (Institut de Recherche pour le Développement – OBHI), Centre Martinique-Caraibe, BP 8006, 97259 Fort de France Cedex, France

 

Abstract The Amazon basin represents 76% of the area of Peru. From north to south, the Andean tributaries of the Amazonas River in Peru are: the Napo River (100 520 km2, 6300 m3 s-1), the Marañón River (360 550 km2, 14 700 m3 s-1) and the Ucayali River (360 490 km2, 13 800 m3 s-1). The total suspended sediment yield exported from Peru to Brazil by these rivers is about 450 ´ 106 t year-1 for the 2004–2006 period (12% from the Napo River, 40% from the Marañón River and 48% from the Ucayali River). As the Amazon flood plain traverses the Andean piedmont and reaches its mouth, sediment yield increases along the Napo and Marañón rivers. This suggests the occurrence of erosion processes in the lowlands as observed in Ecuador, rather than the occurrence of sedimentation as observed along the Madeira River in Bolivia. At all the study stations, discharge and suspended sediment yield show a very high degree of seasonal variation.

 

Key words  Amazon basin; hydrology; Peru; suspended sediment