The Manzanares River is an ecosystem that has experienced significant population growth in
recent decades. This growth could influence in the retention capacity of inorganic chemical species in its sediments,
potentially serving as a sink for these materials. To understand how rapidly these species can accumulate, it’s essential
to study the characteristics of the river sediments throughout the watershed. In this study, granulometric analysis was
conducted on 29 sediment samples collected over five years (2017-2022) during dry periods. These samples were
distributed across the three sub-basins (Upper, Middle, and Lower) of the river. The wet separation technique was
applied to determine the predominant grain type, and classification was done using the SHEPPARD triangle. Here
are the findings: In the Upper sub-basin, the percentage of fine sands ranged from 1.69% to 45.37% at the Aricagua
station. In the Middle basin, fine sands predominated in all sampled stations, varying from 4.75% to 40.84% at
the sand pits station. In the Lower basin, sediments were primarily composed of fine and very fine sands. Notably,
stations 23 (González de Ocampo Bridge) and 24 (AVECAISA company) exhibited the presence of mud due to
natural processes. Overall, the sediment characteristics in this ecosystem are described as sandy, except in the Lower
sub-basin, where natural processes lead to mud presence.
