Monitoring suspended sediment transport in two moutainous river basins: the Carapelle and the Celone (Apulia, Italy)

Abstract

Sediment load quantification is an important task in river basin management, as it provides the order of magnitude of soil loss. Yearly sediment loads were quantified in two river basins of the Apulia region, the Carapelle (506 km2) and the Celone river basin (72 km2), For the Carapelle river basin, streamflow and suspended sediment concentrations (SSC) were monitored from 2007 to 2011 with an infrared optical probe and suspended sediment load at the yearly basis was quantified by integration of instantaneous flux. For the Celone river, continuous measurements of streamflow and discrete measurements of SSC taken, from 2010 to 2011, in all hydrological conditions (high, normal and low flow) were used to develop sediment rating curves. In particular, different sediment rating curves were developed for the entire dataset and three subsets of data identified based on the hydrological conditions and loads were computed with and without a back-transformation correction factor. At the Celone river gauge, annual specific sediment load ranged from 2.4 t ha−1 yr−1to 6.06 t ha−1 yr−1. At the Carapelle river gauge, the annual specific sediment load ranged from 0.9 t ha−1yr−1to 7.45 t ha−1 yr−1. The results of the present study show that the hydrological regime is the key factor in sediment transport in the Celone and Carapelle basins and that the duration of the sampled period, and its characteristics (wet or dry) may have a great impact on sediment loads.