Suspended sediment concentration controlling factors: an analysis for the Argentine Pampas region

ARES, MARÍA GUADALUPE; VARNI, MARCELO; CHAGAS, CELIO

HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES

IAHS PRESS

Lugar: Wallingford; Año: 2016 vol. 61 p. 2237 - 2248

0262-6667

In the Argentine Pampas region, there is little information about sediment concentration in agricultural catchments. The aims of this work are: (1) to analyse fluctuations in sediment concentration and discharge, as a first attempt to characterize hysteresis patterns; and (2) to study sediment concentration controlling factors and to assess the importance of these factors usingprincipal components analysis and a multiple regression model. Twenty-five events registered during 4 years in a 560 ha gauged basin of Argentina were studied. Analysis of data suggested a positive clockwise pattern. The multiple regression model was performed with three factors obtained by principal component analysis: runoff, precipitation and antecedent conditions factors.The model explained 83% of the variability of sediment concentration. Runoff factor contributed to modelled sediment concentration with the highest magnitude, followed by precipitation and antecedent condition factors. Although the watershed is under conservation tillage, rill erosion seems to be the main source of sediment concentration.