The use and occupation of the floodplain of the Macacos River (South Area of Rio de Janeiro)
ISBN 978-85-88783-11-9
Authors
1Rodrigues Barbosa, D.; 2Oliveira Lopes, L.; 3Gilla da Silva, I.
1UNIVERSIDADE ESTÁCIO DE SÁ Email: debora.rodrigues.geo@gmail.com
2UNIVERSIDADE ESTÁCIO DE SÁ Email: leonardomglopes@gmail.com
3UNIVERSIDADE ESTÁCIO DE SÁ Email: ygilla@hotmail.com
Abstract
INTRODUCTION According to Barbosa (2013), the acelerated process of urbanization in the metropolitan area of the Rio de Janeiro has caused a large number environmental problems to the population, overall associated with disordered occupation of floodplains, which are flat lands near the bottom of a river valley, flooded when the flow of the watercourse exceeds the normal capacity of the channel, also called lowland, larger bed.So it a very important to raise the aweareness of the population and planning from goverment to set and guied the risk areas, and raise the proper development of the area and the population. The main goal of this project is to set and classify de use and occupation of the land of flooded are of the watershed Macacos River which drains part of the South Zone, the Rio de Janeiro, at the Horto Community and the Jardim Botânico, emptying the Rodrigo de Freitas Lake. MATERIALS AND METHODS For the analysis of the watershed of the Apes River, the work was done in different stages. The first consisted of bibliographic/cartographic selection. The second step was the acquisition of the letters official maps 1: 10,000 produced by the City of Rio de Janeiro and update using 2010 images. Later there was a delineation of the basin and scan with the same use of GIS software Arcgis 10.1. For the delineation of the floodplain, we sought the altimetry gap between 0 and 40 meters, through the interpretation of the writings of Silva (2003). The last step was to conduct field visits to understand the spatial dynamics of the river basin in question and the real situation of the floodplain, in October. RESULTS AND DISCUSSION The river basin of the Apes is located South Zone of Rio de Janeiro and has an area of 4,8km2, has extended the W-E direction and its source is stuck on the crystalline rocks of the Tijuca Massif, where predominate biotite gneiss, quartz, plagioclase and garnet. This geological substrate maintains a fairly sloped relief plan becomes abruptly, near the Horto Community, at 75 meters above sea level, where the river begins to cut horizontalized extensive sub-sections covered with sediments (alluvium). The growing advance of the occupation on protected areas and on flood plains, without planning, it is independent of its use, possibly represents an area of risk for the population, because it is in plain fluvial processes that start over the basin are reflected, as periodic, flooding due to increased river flow in the amount of sediment deposit, often originating from erosion and even impoundment of water, due to the accumulation of sediment or even trash along the affluents. The flood area of the Apes River has 1,1km2, incorporating a wide horizontally sub area which has different uses and occupation. The forested area (Atlantic Forest remnants) represents almost 20% of the total area of the floodplain and located mainly near the foot of the steep slopes of the Tijuca Massif. The secondary vegetation, with 24% of the floodplain, is mainly observed in the lower course of the river, and is represented floristic architectural and design institute of the Jardim Botanico of Rio de Janeiro, where it is possible to identify numerous domestic and foreign plant species. The Urbanized Areas represent 53% of the researched area and consist principally of constructions in the western and northern portions of the plain. Near the Horto Community, there is a strong human pressure and secondary vegetation, is interwoven into the urban fabric. The growth of the Jardim Botânico neighborhood, of the middle class, from the second half of the last century offered strong building in the northern part of the floodplain. CONCLUSION Monitoring these areas will benefit the entire population, and serve as a tool for planning the use and occupation of land. So, the city of Rio de Janeiro will have an important tool for environmental monitoring, applied with the legislation, diminish the effects of flooding.