Objective:

The general objective of this research was to understand the repercussion of flood events on the export of suspended solids and organic carbon in the Oka river catchment for the period from 1001-2009 to 09-30-2012).

Methodology:

A hydrometeorological station was installed at a point at the catchment mouth allowing the continuous collection of information on: rainfall, river flow, turbidity, etc. The correlation between turbidity measured in the field (TRB) and suspended solids concentration (CSS), determined at the laboratory level, was established as a polynomial function of the first degree. The load of suspended solids (SS), organic carbon in dissolution (COD) and organic carbon in the form of suspended particles or particulate (COP), was determined by multiplying the flow rate by the concentration of each one, applying it for each period of time required.

Results:

Total exports were estimated at 2,267.6 t of SS, 104.3 t of COD and 53.3 t of COP, representing rates in î km 2 year' of 71.85 for SS, 3.30 for COD and 1.68 for COP (average values of the three hydrological years studied).

Conclusions:

The statistical study revealed that for this catchment, the most important agents in the transport of SS, COD and COP are: precipitation and the volume of water transported. Suspended solids were transported especially during the months from autumn to winter, when the most intense floods occur most frequently, being these the most important in the contribution of suspended solids and organic carbon to the outlet of the catchment.

Financing:

University of the Basque Country (UFI11/26).