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Resumo: O objetivo deste trabalho foi elaborar um novo mapa de erosividade da chuva para o Brasil, utilizando séries pluviométricas superiores a 20 anos, e analisar a distribuição espacial dos valores de erosividade. Dados de chuvas de 1.521 estações foram aplicados a 75 equações de regressão que relacionam a precipitação média anual (P) e o coeficiente de chuvas (Rc) com o índice de erosividade (EI30). Os valores de erosividade para os locais não amostrados foram obtidos por interpolação, com uso do método de krigagem ordinária. Os índices mais elevados foram observados entre novembro e fevereiro. Os resultados consistem de interpolações que apresentam desempenho satisfatório para a estimativa da distribuição espacial da erosividade média anual das chuvas e do EI30, ao longo dos meses do ano. Assim, estes mapas podem auxiliar no planejamento da conservação do solo e da água, a partir do delineamento das regiões e das épocas do ano mais críticas quanto à erosividade da chuva.

to study the diurnal variability of the cross-shelf circulation. This period was chosen because it had a steady upwellingfavourable wind condition modulated by a diurnal cycle much similar to sea breeze.The daily variability of the observed cross-shelf circulation consisted of three distinct periods: a morning period with a 3-layer vertical structure with onshore velocities at mid-depth, a mid-day period where the flow is reversed and has a 2-layer structure with onshore velocities at the surface and offshore flow below, and, lastly, in the evening, a 2-layer period with intensified offshore velocities at the surface and onshore flow at the bottom. The observed cross-shelf circulation showed a peculiar vertical shape and diurnal variability different from several other systems described in literature. We hypothesize that the flow reversal of the cross-shelf circulation results as a response to the rapid change of the wind magnitude and direction at mid-day with the presence of the cape north of the mooring site influencing this response.A numerical modelling experiment exclusively forced by winds simulated successfully most of the circulation at the ADCP site, especially the mid-day reversal and the evening's upwelling-type structure. This supports the hypothesis that the cross-shelf circulation at diurnal timescales is mostly wind-driven. By analysing the 3D circulation in the vicinity of Cape Sines we came to the conclusion that the diurnal variability of the wind and the flow interaction with topography are responsible for the circulation variability at the ADCP site, though only a small region in the south of the cape showed a similar diurnal variability.The fact that the wind diurnally undergoes relaxation and intensification strongly affects the circulation, promoting superficial onshore flows in the leeside of Cape Sines. Despite the small-scale nature of the observed cross-shelf circulation, onshore flows as the ones described in this study can be particularly helpful to understand the transport and settlement of larvae in this region and in other regions with similar topography and wind characteristics.

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