SUSCETIBILIDADE A ESCORREGAMENTOS TRANSLACIONAIS NA BACIA DE DRENAGEM DE FRADINHOS, EM VITÓRIA-ES

Código

PAP112

Autores

Julia Frederica Effgen, Jeniffer Oliveira Nepomuceno do Couto, Patrício José Moreira Pires, EBERVAL MARCHIORO

Tema

RISCOS E IMPACTOS DE DESASTRES RELACIONADOS A PROCESSOS SEDIMENTOLÓGICOS

Resumo

Shallow landslides are commongeomorphological processes in southeastern Brazil, conditioned bycharacteristics of relief and climate, among other factors. In Vitóriathat?s also true, with major events of landslidescausing human, economic and socio-environmental losses, like the Morro do Macaco landslide (1985). Therefore, we aim to analyze the areas susceptible to shallow landslides in the Fradinhos watershedthrough the physically based SHALSTABmodel, which prioritize slopes and subsuperficial flow convergencein its calculations. For the model?s parameterization samples of soils were taken in three places with different land use and cover,and two had landslide scars on the proximities of the sampling sites.The Fradinhos watershed has most of its area classified as stable (42.5%), whereas 25.7%of the watershed?s areawere classified as unstable areas.Those stable areas are associated with flat and lower slopes,with convex to straight flow convergence.Theunstable areas area associated with steep slopes, with strong flow convergence. The intermediary stability classes amount to 31.8% of the watershed and are comprised of transition areas between the unstable and stable areas, with slopes varying from gentler to steeper ones and flow convergences ranging from convex to convergent.For validation, we used the Municipal Civil Defense?sreports of landslides to compare with the model and generate a contingence table. The model?s performance was satisfactory, asa first approach to the subject of shallow landslides on the Fradinhos watershed, with 61% of true positive rate.