Exploring landslides?fluvial suspended sediment association in a semi-arid basin in central Chile.

VERGARA I.; GARREAUD R.; MORERIAS S.M.; ARANEO D.; BEIGT D.

GEOMORPHOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2022 vol. 402 p. 108 - 129

0169-555X

The systematicmonitoring of landslides is an essential input for their characterization and subsequent reduction of their risk. Along thewestern subtropical Andes, fieldmonitoring is scarce, so alternativemethods that can improve the monitoring are valuable. In this work, the capacity of fluvial suspended sediment to detect the occurrence of landslides in a basin was explored, emphasizing how the relationship varies depending on the hydrosedimentological variable, the triggering causal factor and the landslide type. The values of suspended sediment concentration (SSC), water discharge (Q) and specific suspended sediment yield (SSY) associated with mass movements were collected from a fluviometric station, as well as maxima of these variables that were not associated with landslides. With these data, different General Linear Models were constructed considering possible non-linear effects of the covariates. Flow-type landslides triggered by rain (most of the events) are correctly predicted, especially using the linear effects of SSC and Q. For this mass movement type the prediction is suitable even for events triggered by isolated, short-lived rains, which are difficult to detect in mountainous areas with meteorological devices.