Boa Vista part of the Northern Amazon and has its genesis in the nineteenth century in 1830 on the right bank of the Rio Branco, which is part of the Rio Negro watershed. Over the past 30 years the urban dynamics has undergone major changes since the population has increased by about 79%, by road account opening, business cycles (diamond and gold principally) and the possibility of establishing residence as a result of donation land by the state government. The passage of Roraima Federal Territory to state of Roraima in 1988 intensifies migration and promotes an urban swelling, causing areas previously unoccupied were occupied such areas include springs and flood plains, or areas unsuitable for habitation due be affected by floods during the months from April to September. Through Remote Sensing and Geoprocessing sought to analyze the process of use and soil cover and its relation to the floods in the city of Boa Vista - RR. Were used satellite images Landsat 5 sensor TM years 1985 and 1995, CBERS-2 CCD sensor of 2005 and Landsat 8 OLI sensor of 2014, which supported the analysis of the transformation of use and land cover with the aid of software PCI Geomatic 10, ENVI 5.0 and ArcGIS 10. To identify the risk of flooding in watersheds
were generated Numerical Models of Land (DEM) of the variables (i) slope, (ii) drainage, (iii) flood away the main waterways of the city of Boa Vista and (iv) use and land cover for use of the Analytic hierarchy Process (AHP), which allows the balancing of the factors listed in processes of diagnosis and decision making, using algebraic language and assisting the integration of indicator data with subsequent ranking of variables listed by assigningweights. Was observed an advancement of the urban area in relation the other use of matrices and their advance has resulted in the suppression of vegetation, waterways and springs towards the west of the city of Boa Vista. The risk areas to flood it was found that 63.6% of the total area of the city of Boa Vista (limit according to the Master Plan 2006) is at low risk of flooding, 8.8% is in the medium risk flooding and 27.6% are at high risk to flooding, concentrated specifically in watersheds Caxangá, Frasco and Pricumã. Physical aspects such as slope influence the impaction by flooding, but the use and occupation of flood plains is one of the important factors for the genesis of the risk to flooding, being necessary to go beyond infrastructure measures such as concretamento the channels, sealing the banks and withdrawal the riparian vegetation cover and act on actions aimed at participation of the population in a participatory way in the planning and management of Boa Vista space, considering social aspects undissociated the biophysical aspects.
|
