Fluvial Sediment Fluxes into the Coastal Zone of the Mediterranean and Black Sea Earth System
Abstract
The coastal geomorphology, shelf sedimentation and trophic status of the Mediterranean and Black Sea Earth System (MBES) are strongly impacted by the fluvial sediment influxes, since more than 200 rivers, associated with catchments extending over 100 km2 each, discharge into the MBES coastal zone. This contribution provides a rational assessment of the riverine suspended (SSL) and dissolved (DL) sediment loads derived from the watersheds of the 4 major marine regions of the MBES, i.e., Western Mediterranean (WMED), Central Mediterranean (CMED), Eastern Mediterranean (EMED) and Black Sea (BLS). Moreover, key morphometric parameters of their catchments have been calculated.
Morphometric analysis was accomplished in a GIS environment, adopting the reference coordinate system WGS84 (2004 version). For the boundaries and topography of the catchment areas the HydroSHEDS dataset (Lehner and Grill, 2013) was utilized. The SSL and DL estimates were based on published field data (e.g., Milliman and Farnsworth, 2013; Poulos and Collins, 2002; Jahoshvilli, 2002); for those parts of the catchment areas that there was a lack of information, sediment yields derived from the known parts were applied. Table 1, appearing below, shows the extents (MA) of the 4 principal MBES marine regions, their corresponding catchment area size (CA), the percentages of the terrestrial components occurring in elevations <500 m (A500) in relation to the whole CA, the mean (Emean) and maximum (Emax) catchment elevations, and the SSL and DL mean annual values. Among the MBES marine regions, the EMED displays the largest catchment area due to the huge Nile River network (2,880,000 km2), followed by the Black Sea basin, although the latter is quite smaller in size. The total sediment influx to the MBES accounts for more than 1200 x 106 t. The MED marine regions demonstrate higher SSL:DL ratios compared to that assessed for the Black Sea; this may be explained by the lower mean catchment elevations and the higher catchment proportion with altitude >500 m.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMEP53E1924P
- Keywords:
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- 1813 Eco-hydrology;
- HYDROLOGYDE: 1824 Geomorphology: general;
- HYDROLOGYDE: 1825 Geomorphology: fluvial;
- HYDROLOGYDE: 1826 Geomorphology: hillslope;
- HYDROLOGY