Author(s): Lorenzo Martini; Lorenzo Picco; Marco Cavalli; Andres Iroume
Linked Author(s):
Keywords: Sediment connectivity; Volcanic eruption; Multi-temporal analysis; Index of connectivity; Blanco River
Abstract: This work aims at analysing variations in sediment connectivity induced by geomorphological changes in a Chilean volcanic-impacted environment. To this end a multi-temporal analysis has been carried out. River basins are transformed by either low-rate disturbances, which alter processes and dynamics at small scale, or high-rate disturbances, performing at catchment scale. Volcanic eruptions deeply affect the landscape at the morphological, ecological and hydrological level, causing also several economic and social damages. The interest in sediment connectivity has recently increased. Sediment connectivity represents an innovative framework to investigate the consequences of such extreme events on sediment mobilization and geomorphic coupling. These last two intertwined components are taken into account to better analyse sediment delivery from hillslope, improving risk management options. Therefore, sediment connectivity analysis aims to highlight the linkages between sediment sources and channel network. In this context, topography, vegetation, and morphology are structural properties driving the (dis)-connection between two areas of the catchment. Based on background theory, a topography-based Index of Connectivity (IC) was developed to evaluate the degree of connection between hillslope and areas of interest through a geomorphometric model. The analysis here presented is based on the multi-temporal application of IC in the Blanco River, southern Chile which was affected by a volcanic eruption occurred in 2008. The main aim is to investigate variations in sediment connectivity induced by geomorphological changes. In this context, the application of IC focuses on the differences between pre and post-eruption land cover conditions and active channel geometry.
DOI: https://doi.org/10.3850/978-981-11-2731-1_156-cd
Year: 2018