Suspended sediment transport in the Magdalena River (Colombia, South America): Hydrologic regime, rating parameters and effective discharge variability

摘要: Abstract The Magdalena River has the greatest length (1612 km) and drainage area (257400 km 2 ) of any river system in Colombia, its watershed occupies 24% Colombian territory. originates Andean Cordillera at an elevation 3685 m flows to mouth Caribbean Sea (Bocas de Cenizas). For this study, information on daily flow discharge ( Q ), suspended sediment transport s mean concentration C from 1990–2010 for River, based measurements Calamar gauging station (the closest mouth), was provided by Institute Hydrology, Meteorology Environmental Studies Colombia (IDEAM Spanish). annual load 169±73×10 6  t yr −1 period 1990–1999 145±47×10 2000–2010, amounting a 14% reduction rate between two periods. rating curve =aQ b also evaluated these periods (1990–1999 2000–2010). An analysis regression coefficients , showed decrease increase after 1999, which coincides with transport. This change might be attributed natural factors, including accumulation Depresion Momposina variation hydro-climatological patterns region. Decreases effective were confirmed using three methods (Log-Normal Normal distribution, magnitude-frequency histogram) study period.