Title
Specific suspended sediment yields of the andean rivers of chile and their relationship to climate, slope and vegetation
Other title
Flux spécifiques de sédiments en suspension des rivières Andines du Chili et leur corrélation avec le climat, la pente et la végétation
Date Issued
01 October 2010
Access level
open access
Resource Type
journal article
Author(s)
Université de Toulouse
Abstract
Using daily suspended sediment and water discharge data, we calculated the current mean annual runoff and Specific Suspended Sediment Yield (SSY) for 66 mountainous and piedmont catchments in Chile. These catchments are located from the extreme north of Chile to Southern Patagonia and cover an exceptionally wide range of climates, slopes, and vegetation. The SSY ranges mainly between 0 and 700 t km-2 year-1 with some exceptions as high as 1780 t km-2year-1. The SSY increases between the extreme north and 33°S and then decreases toward the south. Sediment and water discharge north of 33°S occur mainly during summer. Farther south the contribution of winter precipitation increases and predominates. When the SSY database is correlated with topographic, climatic and vegetation indices, it is found to correlate significantly with runoff and mean slope only. In order to concentrate on erosion processes in the mountain range, 32 mountainous catchments were selected along a strong north-south SSY gradient between 27°S and 40°S. From north to south, SSY inreases strongly with runoff and then decreases, even while runoff keeps increasing. In catchments where SSY is low, although runoff is high, the mean slope is less than 40% and the vegetation cover is greater than 8%. For the other catchments, runoff variations explain 67% of the variance in sediment yields. Thus, SSY seems to be controlled by vegetation cover and slope thresholds. In addition, SSY also correlates with glacier cover. However, a correlation between SSY and seismicity, although possible, is ambiguous. © 2010 IAHS Press.
Start page
1190
End page
1205
Volume
55
Issue
7
Language
English
OCDE Knowledge area
Oceanografía, Hidrología, Recursos hídricos
Geología
Subjects
Scopus EID
2-s2.0-78650439772
Source
Hydrological Sciences Journal
ISSN of the container
21503435
Sources of information:
Directorio de Producción Científica
Scopus