Characterization of gullies in Maranhão island

Abstract

The soil erosion is a significant problem that beyond the environmental degradation, can involve risks of material damage and human lives losses, mainly in urban areas. Prevention or recovery actions are important and demands planning that consider the socio-economic urban conditions and environmental particularities. In that sense, this study presents an erosive features characterization in the Island of the Maranhão, reacting to the large occurrence of the soil erosion in this area, in contribution for its causal understanding. The applied methodology consisted on field analysis, acquisition of representative soil samples, and laboratorial procedures, where the samples were characterized according to their chemical, physical and mineralogical characteristics. The analytical results show that the soils are, in general, very sandy or silty; generally not plastic and predominately kaolinitic. Soil penetration resistance and infiltration taxes were measured and show differences to resistance compacting and soil infiltration, induced for different soil uses, disclosing narrow correlations between the soil behaviour and human activities.