Hydrological processes in wathershed within the State Park of Serra do Mar, Santa Virginia stewardship

The present paper aimed to describe the hydrological functioning of a small catchment covered by the Atlantic rainforest within the State Park of Serra do Mar, Sao Paulo state, Brazil. To reach these goals, the hydrological processes were monitored during 2008 and 2009. The surface runoff, groundwater, streamflow, precipitation, net precipitation and soil water storage at 0.15m, 0.30m, 0.50m and 0.90m, were monitored through nine 2.25 m2 plots, tensiometer, tipping-bucket rain gauges, trough-type collectors and H-flume, respectively. Aiming to clarify the soil hydrological processes, the soil saturated hydraulic conductivity was measured in the field at the depths of water storage measurements using a constant head permeameter. For 2008, the annual precipitation (P) was 1716 mm. Interception losses accounted for 33% of the annual precipitation. The runoff coefficient was 40% of annual rainfall. For 2009, annual precipitation was 3003 mm. Approximately 32% of rainfall was intercepted. Runoff coefficient was 48% of annual rainfall. The predominance of low rainfall intensity (0 - 5 mm h(-1)) substantially below the K(sat )median at 0.15 m allowed us to infer that the soil accommodates the majority of the rain events. This inference is corroborated by low surface runoff coefficients. The higher precipitation in 2009 caused a significant increase in throughfall, surface runoff a daily flow relative to 2008, showing the temporal variability that high precipitation years promote on the hydrologic dynamic of catchments covered by the Atlantic Rainforest.