Callède, J., Ronchail, J., Guyot, J.L., and De Oliveira,
E. (2008) Amazonian deforestation: its influence on the Amazon discharge
at Óbidos (Brasil). Rev. Sci.
Eau 21 (1) : 59-72. [article in French]
Original title: Déboisement amazonien : son influence
sur le débit de l'amazone à Óbidos (Brésil).
This survey completes our earlier work on the evolution of
the Amazon discharge at Óbidos
from 1903 to 1999. In the Amazon basin above Óbidos (4,680·103
km²), 341·103 km² were
deforested between 1976 and 2003. The impact of this deforestation on the mean
was estimated using a water balance approach from 1940 to 2003. The evolution
of the runoff
coefficient indicates that there was a 5% increase in the mean annual discharge
over the 22 years
from 1981 to 2003. The number of strong floods was five time higher during
this period than it was
before. On the other hand, it seems that there is no influence of the deforestation
on the low flows.
Key-words: South America, Amazon catchments, Óbidos, rainfall, discharge,
Ronchail, J. : LOCEAN/IPSL et Département de
Géographie de l’Université Paris VII, 4, place Jussieu,
75005 Paris, France 2 IRD, Casilla 18, 1209 Lima