Modeling landslide activity and sediment connectivity after eruptions: Insights from the Blanco River (Chile).

Volcanic eruptions can disrupt entire river basins by affecting the hydro-geomorphic characteristics of channel networks and hillslopes. Reports suggest a pulsed and delayed increase in landslide activity following the eruptions, which, depending on the degree of linkage between hillslopes and channels, i.e.

Assessing the effect of fire severity on sediment connectivity in central Chile.

Chilean territory is recurrently affected by severe wildfires, which drastically reduce the forest cover and promote runoff, soil erosion and slope instabilities. To understand how the geomorphic system responds to wildfires in terms of sediment dynamics, the assessment of sediment connectivity, i.e.

Sediment connectivity changes in an Andean catchment affected by volcanic eruption.

River systems are continuously affected by multiple natural and anthropogenic phenomena. Among major natural disturbances, volcanic eruptions have the capability to overthrow the forms and to modify dramatically the morphological setting and sediment connectivity of the system. Moreover, the input of sediments in the channel network can lead to active channel widening, bed aggradation and river scouring, which in turn may affect downstream human settlements.

Cascading processes in a changing environment: Disturbances on fluvial ecosystems in Chile and implications for hazard and risk management.

The compound hazard effects of multiple process cascades severely affect Chilean river systems and result in a large variety of disturbances on their ecosystems and alterations of their hydromorphologic regimes leading to extreme impacts on society, environment and infrastructure. The acute, neo-tectonically pre-determined susceptibility to seismic hazards, the widespread volcanic activity, the increasing glacier retreat and the continuous exposure to forest fires clearly disturb entire riverine systems and concur to trigger severe floods hazards. With the objective to refine the understanding of such cascading processes and to prospect feasible flood risk management strategies in such a rapidly changing environment we first classify the large river basins according to a set of disturbances (i.

Using (137)Cs and (210)Pbex and other sediment source fingerprints to document suspended sediment sources in small forested catchments in south-central Chile.

A study of the impact of forest harvesting operations on sediment mobilization from forested catchments has been undertaken in south-central Chile. The study focused on two sets of small paired catchments (treatment and control), with similar soil type, but contrasting mean annual rainfall, located about 400 km apart at Nacimiento (1200 mm yr(-1)) and Los Ulmos (2500 mm yr(-1)). The objective was to study the changes in the relative contribution of the primary sources of fine sediment caused by forestry operations.