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RESUMO O presente trabalho detalha aspectos importantes a serem observados nos procedimentos de seleção e caracterização de uma bacia experimental florestal e instalação de um sistema de monitoramento hidrológico, com enfoque em fluviometria, pluviometria e tensiometria. Para tanto, utilizou-se a experiência adquirida no estudo de caso da bacia experimental do Rio Araponga (ARA), localizada no município de Rio Negrinho (SC). O levantamento dos pontos de nascentes e confluências permitiu a extração da rede de drenagem mais próxima da realidade considerando a base cartográfica disponível (escala 1:10.000). A determinação dos locais adequados dos aparelhos de monitoramento hidrológico foi possível somente com levantamento topográfico mais detalhado (escala 1:5.000).

The rainfall events that occurred in the Cubatão do Norte River watershed, Santa Catarina State, Brazil, in 2008, were characterized by both high intensities and amounts and triggered landslides in this watershed. The objective of the present study was to analyze the influence of landslides on the turbidity and the total solid concentration (TS) in this river using turbidity, TS, and river discharge data obtained from March 23, 2008, to June 11, 2010. The comparison between turbidity and discharge patterns implies that the landslide process was not continuous and increased the turbidity intermittently and irregularly. The sediment yield during the landslide occurrence was approximately five times higher than without the landslide, even though the discharges were similar. The turbidity/discharge relationship during the landslide occurrence was markedly different from that before and after the occurrence. The correlation coefficients between turbidity and TS showed that the landslide significantly changed the sediment yield in this watershed. The result indicates that sediment yield estimations at the watershed level should be treated more carefully when landslides occur.

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While rainfall interception controls how much water will be ultimately available for many ecological functions, it is not well understood how canopy structure controls the spatial and temporal distribution of throughfall inside forests. Specially in subtropical and highly heterogenous forests, such as the Atlantic Forest in Brazil, rainfall interception has been only timidly studied. In this paper we investigated how the spatial and temporal variations of throughfall are controlled by the canopy structure. Throughfall spatial variability was measured for a period of over a year using 28 throughfall gauges uniformly distributed in a 28 m² Atlantic Forest plot in Southern Brazil. We proposed the use of the number of overlapping crowns (NOC)