M?dio Curso da Bacia do Rio Jacu?pe, Bahia: Proposta Metodol?gica para estimativa de susceptibilidade ? degrada??o ambiental

Autor: Silva, Oriana Araujo da
Přispěvatelé: Chaves, Joselisa Maria
Jazyk: portugalština
Rok vydání: 2010
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UEFS
Universidade Estadual de Feira de Santana (UEFS)
instacron:UEFS
Popis: Submitted by Bruno Matos Nascimento (brunomatos@uefs.br) on 2020-06-09T18:13:25Z No. of bitstreams: 1 ORIANA ARAUJO_M?dio curso da bacia do rio Jacu?pe_Bahia_ proposta metodol?gica para estimativa de.pdf: 44980082 bytes, checksum: 03617e4c41415ff9415d1f02f996c8f7 (MD5) Made available in DSpace on 2020-06-09T18:13:25Z (GMT). No. of bitstreams: 1 ORIANA ARAUJO_M?dio curso da bacia do rio Jacu?pe_Bahia_ proposta metodol?gica para estimativa de.pdf: 44980082 bytes, checksum: 03617e4c41415ff9415d1f02f996c8f7 (MD5) Previous issue date: 2010-04-20 Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB Currently the changes imposed to landscapes are faster and more intense in several places of the planet due mainly to the appearing and the use of new techniques and machines which transform them into artificial or cultural landscapes. In the medium course of Jacu?pe River Basin (JRB) ? core area of Brazilian semi-arid region ? artificial landscapes are dominant. Such landscapes are result of land cover changes identified in previous research which registered a strong process of anthropization mainly in the form of native vegetation removal by introduction of pastures and urban occupation well as for annual and perennial crups. The elements which constitute the present territorial configuration reflect the historical process of occupation of the landscape discussed in this work whose general aim is the identification of the levels of susceptibility to environmental degradation with the use of integrated analysis of socio-environmental indicators. Due to the geosystemic magnitude of the study area geotechnology tools ? specifically the interpretation of satellite imagery and spatial data modeling combined with fuzzy spatial inference ? were used in this work. The vegetation cover map ? natural or anthropic ? produced through supervised classification of Landsat TM5 image (2008) indicated that 74% of the medium course area of JRB do not have any kind of vegetation cover. Thus, with the use of distance maps (buffers) ? in order to define the degrees of pertinence of those variables to the fuzzy set of susceptibility to environmental degradation in the medium course of the basin ? the work estimated the influence zone of the cities, the roads, and the rivers on the vegetation cover as well as how they are related to types of soil and degrees of slope. After testing different algorithms, the work concluded that fuzzy interpolator (sum) combined more acurately the variables used. That result produced a map with 5 levels of susceptibility to environmental degradation: high, moderately high, intermediate, moderatley low, and low. The work also demonstrated that the medium course of JRB is seriously affected in terms of susceptibility to environmental degradation especially in central area and in the cities of Riach?o do Jacu?pe, P? de Serra, Nova F?tima and Gavi?o. In the towns of S?o Jos? and Capela, the major concern is the the expansion of the algaroba (Prosopis juliflora). In the cities or towns where the predominant vegetation cover is the sisal (Agave sisalana), the areas which are more susceptible to environmental degradation are located near the venues of municipalities but there is also areas at high risk mainly those related to intensive cattle-raising. Atualmente as mudan?as impostas ?s paisagens s?o mais r?pidas e intensas em diversos lugares do planeta, devido principalmente ao surgimento e utiliza??o de novas t?cnicas e m?quinas, transformando-as em paisagens artificiais ou culturais. No m?dio curso da Bacia Hidrogr?fica do Rio Jacu?pe (BHJ) - ?rea ?core? do semi-?rido brasileiro - predominam as paisagens artificiais. Tais paisagens s?o resultantes da mudan?a de cobertura da terra constatada em pesquisas anteriores, que apontou um forte processo de antropiza??o nesse trecho da bacia, devido ? retirada da vegeta??o original para a implanta??o de pastagens, ocupa??o urbana, culturas anuaia e permanentes. Os elementos que constituem a configura??o territorial atual refletem o processo hist?rico de ocupa??o do espa?o geogr?fico discutido nesse trabalho, cujo objetivo geral ? identificar os n?veis de susceptibilidade ? degrada??o ambiental, a partir da an?lise integrada de indicadores socioambientais. Devido ? magnitude geossist?mica da ?rea de estudo, utilizou-se as geotecnologias, especificamente a interpreta??o de imagens de sat?lite e a modelagem espacial de dados, combinados por infer?ncia espacial fuzzy. O mapa de cobertura vegetal - natural ou agr?cola - produzido por classifica??o supervisionada da imagem Landsat TM5, de 2008, evidenciou que 74% da ?rea do m?dio Jacu?pe n?o possui nenhum tipo de cobertura vegetal. Assim, estimou-se a zona de influ?ncia das cidades, das estradas e dos rios sobre a cobertura vegetal, a partir de mapas de dist?ncia (buffers), a fim de definir os graus de pertin?ncia dessas vari?veis ao conjunto fuzzy de susceptibilidade ? degrada??o ambiental no m?dio Jacu?pe, e foram associados a tipos de solo e graus de declive, al?m do ?ndice de desenvolvimento humano. Ap?s o teste com diferentes algoritmos concluiu-se que o interpolador fuzzy SUM combinou mais fidedignamente as vari?veis utilizadas, produzindo o mapa com 5 n?veis de susceptibilidade ? degrada??o ambiental: alta, moderadamente alta, intermedi?ria, moderadamente baixa e baixa. Demonstrou-se nesse trabalho que o m?dio Jacu?pe encontra-se seriamente comprometido em termos de susceptibilidade ? degrada??o ambiental, especialmente a ?rea central e os munic?pios de Riach?o do Jacu?pe, P? de Serra, Nova F?tima e Gavi?o. J? nos munic?pios de S?o Jos? e Capela, o que preocupa ? o avan?o da cobertura vegetal devido ? expans?o de algarobas. Nos munic?pios onde a cobertura vegetal predominante ? o sisal, as ?reas de maior susceptibilidade ? degrada??o ambiental encontram-se pr?ximas ?s sedes municipais, mas h? tamb?m ?reas sob alto risco, principalmente as que se relacionam ? pecu?ria extensiva.
Databáze: OpenAIRE
Externí odkaz: