Correlation between soil erosion by water and degradation, retrogradation phenomena

Mario Falace, Giuseppe Frega, Francesco Lamonaca

Thursday 2 july 2015

17:54 - 17:57h at Mississippi (level 1)

Themes: (T) Sediment management and morphodynamics, (ST) Sediment transport mechanisms and modelling, Poster pitches

Parallel session: Poster pitches: 13A. Sediment - Coast

Soil erosion varies greatly over space and neglecting information about estimation uncertainty may lead to inappropriate decision-making. Spatially distributed models coupled with Geographic Information System and a geo-statistical approach allow to identify areas sensitive of soil loss and carry out a good representation of the erosion process. Slope instability is correlated to landslide generation in soil retrogradation and degradation process. The objective of this paper is to carry out and validate correlation between soil erosion process and slope instability, degradation and retrogradation phenomena, and to propose a procedure that allows mapping the areas more prone to risk erosion and happening landslide generation in soil retrogradation and degradation process from the proposed correlation. Using a graphic calculation, based on LabView tool, from the proposed correlation is possible to previously localize and mapping the areas more prone to soil erosion phenomena. So using the proposed approach it's possible to previously identify the areas that could be interest from intense erosive phenomena. The first results show as the proposed procedure identifies the foot of the registered landslide and other areas interested by this phenomena, with an accuracy that allow urban planning as a decision making support. From the body to the crown of the landslide, the model prediction is less accurate. It is due to the fact that the landslide generation happened by retrogradation phenomena. By the first fall, the slope equilibrium become precarious, so it 's realize slope instability conditions and it starts a trigger effect in case of aggressive rainfall or earthquakes, which begin the landslide phenomena by retrogradation. An important future development of these studies can be the mapping with accuracy and precision of the total area interested in these phenomena using the equilibrium slope models coupled with the proposed approach.