EDAFOLOGIA, Vol. 10 (2), pp. 127-133, 2003
APORTE DE SEDIMENTOS DE UNA CUENCA Y RELACIÓN DE DESCARGA EN UN RÍO DE LA ZONA HÚMEDA ESPAÑOLA
M.E. RIAL, C. VARELA, M.A. ÁLVAREZ, F. DÍAZ-FIERROS
Dpto. Edafoloxía e Química Agrícola. Facultade de Farmacia. USC. C.P.15782. A Coruña. España. edmitas@usc.es
This study reports the results of continuous flow measurement and regular suspended solids sampling (30 manual sampling days and 15 automatic sampling days, all during periods of storm flow) in the river Carballas (Galicia, NW Spain), which drains a watershed of 11.2 km2 with 33.6% of area dedicated to pasture and 66.4% to forestry. The results obtained indicate close relationships betwe- en discharge and suspended solids concentrations. Most suspended solids transport takes place during periods of storm flow (about 5% of the total time period considered), and 90% of the time the suspended solids concentrations are less than 50 mg/l, implying low sediment loads. We also applied the USLE met- hod in conjunction with a GIS approach (ArcView) to estimate annual erosion rates and thus to estimate the sediment delivery ratio (SDR) for this watershed. SDR proved to be only 1.75% of total watershed erosion.
Key words: sediment load, erosion, sediment delivery ratio (SDR).