Efeitos da dinâmica pluviométrica na interceptação e precipitação interna em uma encosta com Floresta Atlântica no Parque Nacional da Tijuca, RJ, Brasil.

Abstract

Given the importance of vegetation cover for the hydric balance, the present paper aimed to analyze the pluviometric dynamics for the net precipitation and interception process, in the forested hillslope in the Tijuca National Park. The influence by a set of independents variables given by hydrometeorological dynamics (rainfall volume and intensity and drought context) was discussed face the temporal modulation for interception and net precipitation, coupled a spatial analyze given by comparisons between hillslope positions (summit; upper hillslope; lower hillslope; valley bottom), where there is a vegetation structure heterogeneity originated by geomorphological context. The volume intercepted at each event varies directly proportional to the antecedent drought time, with the complementary effect of the rainfall volume in the previous 15-days. The percentual interception varies inversely proportional to the gross precipitation and its intensity. It is about the interception wich best manifests the significance of the spatial variations, with highlights for the summit área, where the canopy openness is bigger. The net precipitation varies under the strong influence – directly proportional – by gross precipitation volumes, being better explained with the complementary effect by the previous drought. The spatial variations on the net precipitation are less significant in comparison to the interception, decreasing the significance in the time of increase of the gross precipitation volumes.