The water balance of a forested tropical basin near Manaus: Impacts of the interannual variability of climate on the hydrological cycle.
Javier
Tomasella, INPE, javier@cptec.inpe.br
(Presenting)
Martin
George
Hodnett, Free University, mhodnett@lineone.net
Luz
A.
Cuartas, INPE, adriana@cptec.inpe.br
Antônio
D.
Nobre, INPA, anobre@ltid.inpe.br
Maarten
Waterloo, Free University, watm@geo.vu.nl
Sylvia
Mota de
Oliveira, INPA, smoli@inpe.gov.br
During 2002, the Carbonsink and Ecocarbon projects set up an instrumented catchment in the Asu Basin, located approximately 70 km NNW of Manaus. The catchment, with a drainage area of a 6.37 km2, collects the discharge from five first order streams, and encompasses the most common landscape forms (and their associated soil types) that occur in the region.
The instrumental layout provides measurements of rainfall and water discharge at high resolution. In addition, a hydrological transect was installed along a characteristic slope. This transect includes neutron probe access tubes to measure soil water content to depths of up to 4.8m, and wells for monitoring the groundwater level from the floodplain to the plateau (catchment divide).
We present results showing the effects of interannual variability of climate on the soil water and groundwater stores and on the streamflow.
Preliminary results suggest a strong interannual signal, with still unknown implications for the hydrological functioning of the catchment on a longer time scale: During 2003, the groundwater storage increase as a result of deep recharge was 500 mm less than in 2002. Since groundwater is crucial to sustaining baseflow in the dry season, we will analyse the potential implications for the overall discharge of the river system in the longer term.
Submetido por Javier Tomasella em 18-MAR-2004
Tema Científico do LBA: SH (Hidrologia e Química das Águas)