Dissertação
Avaliação do impacto da ocupação urbana sobre as características hidrosedimentométricas de uma pequena bacia hidrográfica de encosta
Fecha
2004-12-22Autor
Belló, Sergio Luiz
Institución
Resumen
The objective of this research was the characterization of two
small areas in different urbanization stages in a small urban hillslope
basin with a total area of 0.53 km2. Two fluvio-sedimentometric
stations and a pluviometric one were installed to characterize the
maximum, mean and minimum discharges during the raining and dry
periods, the sediment yield and also the transported material particle size analyses. The data were collected and analyzed between May 1st
and December 20th , 2003 with 8 registered events at the less
urbanized area and 7 events at the urban area. The sediment yield
characterization was done by composing the relation of the liquid
discharges with the solid discharges and the overland flow volume
was also considered. The studying area and the sediment yield
parameters were determined from the rating curve, which related the
product of the superficially flowed volume and the peak discharge by
the transported solid discharge; and the total superficially flowed
volume by the total transported solid discharge. The bed load
transported material and the ones transported by the storm were
characterized through the particle size and sedimentation analyses.
The suspended sediment mean concentration was determined through
the weighting and filtering method and the laboratories analyses
determined that the samples are from sandy origin. The results were
analyzed and compared between the two measurement structures and
they were also compared to other studies. It was observed that the
sediment yield and the transported sediment characterization were as
expected. The mean sediment yield to the urbanization stage area was
0.141 (t/ha.day) and to the urban area it was 0.271 (t/ha.day).