This paper presents results from the MASW method (multichannel analysis of surface waves) in a hill side area of unsaturated soils in the Ubatuba City,Brazil, a site where numerous mass movements have occurred. It discusses the influence of some acquisition parameters, such as, the natural frequency of geophones and minimum and maximum offsets in dispersion image results and does a comparative analysis of the results obtained in repeated tests carried out in the same place, under the same conditions, during the dry and rainy seasons. The comparative analysis for the inversion results in different periods showed that the values of S-wave velocity during the dry season were higher than those for the rainy season; these variations were attributed to the higher cohesion of the soil structure in the dry season. The final 1D velocity profile model with depth was consistent with the results of other geophysical and geotechnical investigations made. Although additional in situ and laboratory geotechnical tests, are necessary (to obtain soil parameters such as hydraulic conductivity, moisture content, soil suction, for example), for a complete characterization of the geotechnical properties of the investigated soil, the result shows that it is possible to use empirical correlations between the Vs profile, from the MASW method, and soil stiffness parameters in order to monitor areas susceptible to landslide.

O presente estudo da hidrologia da bacia hidrográfica do Rio Doce no estado do Espírito Santo contou com o tratamento estatístico da série histórica (1968 a 2021) de dados da HIDROWEB v3.2.6 da Agência Nacional de Águas, além de dados de radar da SRTM. As vazões acompanham a variação dos dados de precipitação média mensal. A vazão média de longa duração (Qmld) apresentou significativa correlação entre as microbacias do Rio Doce. Já as vazões médias mensais de referência (Q90) e (Q7,10), adquiridas da curva de permanência, mostraram baixa correlação com a variação da precipitação durante um ano. Deste modo, conclui-se que a hidrologia da bacia é principalmente regida pelo controle morfoestrutural, que por sua vez exerce forte influência nos fatores geomorfológicos e fluviais, sobretudo em períodos de estiagem na bacia hidrográfica.

Using direct and indirect methods to assess the influence of high-energy waves over beach sedimentary balance (Brazilian Northeastern region).

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