Fragilidade ambiental potencial da bacia hidrogr?fica do rio Jequitinhonha, Minas Gerais, Brasil

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-08-17T22:50:17Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) luciano_cavalcante_jesus_franca.pdf: 8536092 bytes, checksum: 448d28dd9ed3febc9eafc32bf9208be2 (MD5)Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-10-05T19:39:21Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) luciano_cavalcante_jesus_franca.pdf: 8536092 bytes, checksum: 448d28dd9ed3febc9eafc32bf9208be2 (MD5)Made available in DSpace on 2018-10-05T19:39:21Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) luciano_cavalcante_jesus_franca.pdf: 8536092 bytes, checksum: 448d28dd9ed3febc9eafc32bf9208be2 (MD5) Previous issue date: 2018Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)A degrada??o ambiental em seu contexto geral ? uma realidade presente em todo o Brasil, que vem desencadeando problemas de ordem ambiental, econ?mica e social, muitas vezes permanentes, outras contorn?veis dado o avan?o da pesquisa em restaura??o e conserva??o de ecossistemas degradados. Estudos de fragilidade ambiental potencial direcionam a compreens?o da susceptibilidade ? degrada??o em bacias hidrogr?ficas, e podem auxiliar na prioriza??o de ?reas no planejamento ambiental, ordenamento territorial, restaura??o, conserva??o e preserva??o florestal e de solos. O objetivo desta investiga??o cient?fica foi de realizar uma an?lise da fragilidade ambiental potencial da bacia hidrogr?fica do rio Jequitinhonha, na por??o do estado de Minas Gerais. A metodologia utilizada foi baseada no estabelecimento de graus de fragilidade, de baixo ? extremamente alto, a partir de avalia??o muticriterial de um conjunto de planos de informa??es ambientais: declividade do terreno, classes de solos, dom?nios geol?gicos, hierarquia de drenagens e pluviosidade. Aplicou-se o m?todo de hierarquiza??o para tomada de decis?es e determina??o da import?ncia dos crit?rios por meio do Analytic Hierarchy Process (AHP), bem como a obten??o do ?ndice e raz?o de consist?ncia da matriz AHP. Para os procedimentos de an?lises em planilhas de dados, utilizou-se o software Excel, e para as an?lises em plataforma SIG, o software ArcGis 10.3.1. A classe de fragilidade ambiental potencial com maior representatividade ? a denominada m?dia fragilidade, e ocorre em uma extens?o de 19.244,1 km?, equivalente a 30% da ?rea total da bacia hidrogr?fica, que ? de 66.319 km?. Uma ?rea de 12.430,57 km? (19,4%) da bacia apresenta fragilidade baixa, 18.540,93 km? (28,9%) sob levemente baixa, e as classe alta e extremamente alta, representam 10.519,63 km? (16,4%) e 3.416,15 km? (5,3%), respectivamente. A Raz?o de Consist?ncia (RC) calculada para a matriz de pondera??o de hierarquiza??o dos crit?rios para a ?lgebra de mapas, foi de 0,0781, dentro dos limites de coer?ncia e confiabilidade aceit?veis pela metodologia AHP. A condi??o de maior ou menor fragilidade ambiental potencial, revela-se principalmente ao grau de prote??o quanto a cobertura vegetal nativa, no contexto das formas de ocupa??o do territ?rio e impactos ambientais sob o qual a bacia hidrogr?fica est? sujeita, condi??es que direcionam ou n?o ? degrada??o dos solos. Destaca-se que, al?m dos resultados obtidos neste estudo, s?o necess?rias outras investiga??es que complementem e testem a combina??o de novos crit?rios, que englobem tamb?m distintos focos de aplicabilidade e tomadas de decis?o nas ci?ncias florestal, ambiental e agr?ria.Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018.The environmental degradation in its general context is a reality present throughout Brazil, which has been unleashing environmental, economic and social problems, which are often permanent, others that are contrived due to the progress of research in restoration and conservation of degraded ecosystems. Potential environmental fragility studies guide the understanding of susceptibility to degradation in watersheds, and may assist in the prioritization of areas in environmental planning, land management, restoration, forest and soil conservation and preservation. The objective of this scientific investigation was to analyze the potential environmental fragility of the Jequitinhonha river basin in the state of Minas Gerais. The methodology used was based on the establishment of degrees of fragility, from low to extremely high, based on a multi-criteria assessment of a set of environmental information plans: terrain slope, soil classes, geological domains, drainage hierarchy and rainfall. The hierarchical method was applied for decision making and determination of the importance of the criteria through the Analytic Hierarchy Process (AHP), as well as obtaining the index and consistency ratio of the AHP matrix. For the analysis procedures in spreadsheets, the software Excel was used, and for the analyzes in platform GIS, the software ArcGis 10.3.1. The class of potential environmental fragility with greater representativeness is the denominated average fragility, and occurs in an extension of 19.244,1 km ?, equivalent to 30% of the total area of the watershed, that is of 66.319 km ?. An area of 12,430.57 km? (19.4%) of the basin presents low fragility, 18,540.93 km? (28.9%) under slightly low, and the upper and extremely high class represent 10,519.63 km? (16.4 %) and 3,416.15 km? (5.3%), respectively. The Consistency Ratio (RC) calculated for the hierarchy matrix of the criteria for map algebra was 0.0781, within the limits of coherence and reliability acceptable by the AHP methodology. The condition of greater or lesser potential environmental fragility is mainly due to the degree of protection of native vegetation cover, in the context of the forms of occupation of the territory and environmental impacts under which the river basin is subject, conditions that degradation of soils. In addition to the results obtained in this study, further research is required to complement and test the combination of new criteria, which also encompasses different foci of applicability and decision making in the forest, environmental and agrarian sciences