Dissertations and Theses

Summary

The lack of environmental indicators to plan the expansion of the agricultural areas can improve soil losses and damages to the agricultural production. The models of land capability help for planning the limitations and degradation risks, contributing to land use policy. The morphometric parameter - ruggedness number (RN) provide a more practical and economical way to track the agriculture land use in basins with areas of low slope and sparse drainage density and the forest land use to areas of steep slope and high drainage density. However, the RN model presents limitations for heterogeneous basins with different geomorphological patterns and geologies. The proposal intends to refine the land capability (RN model) using the levels of landscape dissection (RN-dissection model), the new methodology add the landform classification. The validation of the new sub-classes of land capability used the soil mineralogical parameter, magnetic susceptibility. The model designed for tropical regions was applied in the Tietê River Basin occupied on the portion of the Western Plateau, located in São Paulo State (Brazil). The modeling generated nine subclasses to better distinguish the land capability in basins through the geological and climatic heterogeneity of the tropical regions, specific to regional and local scales. The mineralogical parameter, magnetic susceptibility-dependent frequency, validated the RN-dissection model. However, the land use conflict interfered in the limit value of the magnetic signature, being more intense in the Serra Geral geological formation. The gains for land use policy planning are of great importance, due to the construction and validation of models that assist the land capability plan are fundamental instruments to implant soil conservation practices in rural areas and help to mitigate soil degradation, a global concern.