Open AccessResultantes geo-hidroecológicas do ciclo cafeeiro (1780-1880) no médio vale do rio Paraíba do Sul: uma análise quali-quantitativa
Author(s) -
Marcelo Eduardo Dantas,
Ana Luíza Coelho Netto
Publication year - 1996
Publication title -
anuário do instituto de geociências
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.202
H-Index - 12
eISSN - 1982-3908
pISSN - 0101-9759
DOI - 10.11137/1996_0_61-78
Subject(s) - deforestation (computer science) , period (music) , sedimentation , radiocarbon dating , fluvial , horizon , hydrology (agriculture) , environmental science , geography , physical geography , archaeology , geology , geomorphology , sediment , physics , geotechnical engineering , structural basin , astronomy , computer science , acoustics , programming language
The coffee cycle represented a period of intense morphodynamic activity, proceeding by a general deforestation. On the Paraíba do Sul Middle Valley, this economic cycle lasted 100 years aproximately (1780-1880). Historical documents, radiocarbon dates and volumetric measurements of the valley fills correlated from the coffee time, have provided informations on the environmental impact, particularly associated with climatic and hidro-erosive processes both on the hillslopes and fluvial domains. Deforestation introduced a drought period up to 6 months and also to an increasing frequency of intense rainstorms, particularly in the summer. Along the Piracema river valley, sedimentation rates attained about 70.000m³km/year. Transfering this volume to the source-area on the hillslopes, it gives an estimate relief downwearing around 7,5 cm depth, resulting on the removal of the organic rich A horizon and showing so, the catastrophic effect of this economic activity, resulting in an extremely wasted degraded landscape.