Vulnerabilidade socioambiental relacionada à enchente e voçorocamento na Bacia Hidrográfica Boa Vista (Manaus - Am)

Abstract

The importance of the watershed in the urban context of Manaus - AM, had historical changes. The emergence and amplification of environmental problems are a reflection of poor urban planning. In this sense, the following research has the objective of analyzing the social and environmental vulnerability in Boa Vista watershed, related to floods and voçorocamentos. In order to reach the main objective, specific objectives have been defined. These are: mapping of land use and occupation in watershed; Identification of areas affected by voçorocamento; Description of areas with flood occurrence; and Characterization of the morphometric aspects of the basin. In the first stage of the research was carried out the data collection, consultations to documents of public agencies and bibliographies pertinent to the theme. Areas affected by voçorocamento were identified using newly processed satellite images with the help of ArcGIS 10.3.1. In the description of the areas with flood occurrence, the flood data from 2008 to 2017 were considered together with the characterization of the dominant BHBV morphologies. The morphometric aspects were delimited by means of geoprocessing. In all stages, the qualitative analysis of the parameters (slope, altimetry and soil use) and its correlation in the SIG environment were performed. Finally, fieldwork was carried out to recognize the area and to prove the pre-identified data. Based on these data was elaborate in SIG’s environment the map of socioenvironmental vulnerability to flood and to the voçorocamento. The Boa Vista watershed maintains its banks partially preserved, with areas with different uses and functionalities, geared towards leisure (bathing and floating). There were identified 07 erosive incisions of the voçoroca type and delimitated some vulnerable points to the flood process. The slope and altimetry of the area are favorable to the development of erosive processes, which occur in areas with slopes above 45% and at altitudes between 75 and 101 m. The areas affected by the floods are the flood plains inserted in the 30m height, in these places there are in addition to factories and trades, structures directed to housing. The distribution of these processes showed a direct relation to the local urban structure. The occupation of these areas continues to intensify over the years, requiring planning for the development of the urban space of the city and application of measures that prevent the appearance and aggravation of future events.