Komba D. E., Nlend B., Braun Jean-Jacques, Boum-Nkot S. N., Audry S., Ndondo G. R. N., Riotte Jean, Nnomo B. N., Ntamak-Nida M. J., Etame J., Fongoh E. J., Bessa H. A., Lagane Christelle, Ngoupayou J. R. N. (2024). Chemical weathering and CO2 consumption in the upper Nyong Basin rivers (Central Africa) : insights on climatic and anthropogenic forcing in humid tropical environments. Science of the Total Environment, 937, p. 173405 [21 p.]. ISSN 0048-9697.
Titre du document
Chemical weathering and CO2 consumption in the upper Nyong Basin rivers (Central Africa) : insights on climatic and anthropogenic forcing in humid tropical environments
Année de publication
2024
Auteurs
Komba D. E., Nlend B., Braun Jean-Jacques, Boum-Nkot S. N., Audry S., Ndondo G. R. N., Riotte Jean, Nnomo B. N., Ntamak-Nida M. J., Etame J., Fongoh E. J., Bessa H. A., Lagane Christelle, Ngoupayou J. R. N.
Source
Science of the Total Environment, 2024,
937, p. 173405 [21 p.] ISSN 0048-9697
A hydrological and hydrochemical database (produced by the M-TROPICS critical zone observatory) in the upper Nyong Basin from 1998 to 2017 was used to evaluate the river's response to climatic and anthropogenic forcing and examine chemical weathering processes. SiO2 and HCO3- constitute about 85 % of the Total dissolved solids (TDS) load, equivalent to 0.12 x 10(9) kg. y(-1). Electrical conductivity (EC), Total dissolved solids (TDS), major cations, major anions (except F and NO3-) and alkalinity (Alk) vary seasonally and follow a predictable model with discharge. Atlantic Meridional Mode oscillation controls the long-term water chemistry. Atmospheric input and silicate weathering are the main factors influencing the Nyong rivers chemistry. However, several indices supported the progressive water quality deterioration by human activities, namely: the excess of Cl- and SO42- after the substraction of atmospheric inputs, the basic pH observed for specific samples, long-term increase in the values of pH, EC, TDS, EC, Mg2+, Ca2+, F, NO3-, HCO3-, Alk, SiO2 and Dissolved Organic Carbon. Runoff and physical erosion have an important control on chemical erosion in the upper Nyong Basin rivers. The chemical erosion rate (3.3 t.km(-2).y(-1)) equals the silicate weathering rate. The CO2 consumption rate, in the Nyong rivers, is lower than the global average (98x 10(3) for silicate weathering and 246 x 10(3) mol.km(-2).y(-1) for chemical erosion) and estimated at 52.3 x 10(3) for silicate weathering and 54.1 x 10(3) mol.km(-2).y(-1) for chemical erosion. At Olama, the most downstream location of the monitoring setup, the Nyong River Basin consumed 1 x 10(9) mol. y(-1) of CO2 by chemical erosion.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Sciences du milieu [021]
;
Hydrologie [062]
Description Géographique
AFRIQUE CENTRALE ; CAMEROUN ; ATLANTIQUE ; ZONE TROPICALE
Localisation
Fonds IRD [F B010090799]
Identifiant IRD
fdi:010090799
