Mapeamento da Vulnerabilidade das Terras da Bacia Hidrográfica do Rio Taperoá.

A inadequacao do uso e do manejo das terras tem degradado os solos, acelerando o impacto das atividades humanas sobre o meio ambiente, particularmente nas regioes semiaridas do Nordeste brasileiro. Partindo do pressuposto de que a erosao do solo e o efeito mais marcante da degradacao ambiental, e que a cobertura vegetal e a declividade do terreno sao os fatores determinantes do processo erosivo, este trabalho teve como objetivo mapear a vulnerabilidade das terras da bacia hidrografica do rio Taperoa atraves do indice de vegetacao por diferenca normalizada e do indice de biomassa da vegetacao lenhosa utilizando imagens de satelite. Foi utilizado o software ERDAS para gerar a imagem-indice e o SPRING para gerar o mapa de vegetacao, declividade e vulnerabilidade. Concluiu-se que a boa correlacao entre os indices possibilitou o mapeamento da vegetacao de caatinga. O cruzamento do mapa de declividade e de vegetacao permitiu diagnosticar a vulnerabilidade da bacia. Constata-se que 28,66% da area total da bacia estao com maior vulnerabilidade. Estima-se que 61,98% da area da bacia estejam em processo avancado de degradacao. Normal 0 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-ansi-language:PT-BR; mso-fareast-language:PT-BR;} Normal 0 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-ansi-language:PT-BR; mso-fareast-language:PT-BR;} A B S T R A C T Inadequate use and land management has degraded soils, accelerating the impact of human activities on the environment, particularly in the semiarid regions of northeastern Brazil. Assuming that soil erosion is the most striking effect of environmental degradation, and the vegetation cover and land slope factors are important determinants of the erosion process, this study aimed to map the vulnerability of watershed land river Taperoa. It was used vegetation index (NDVI) satellite images to estimate the degree of vegetation cover, expressed by the biomass index of woody vegetation (IBVL) and SRTM database to generate the slope map. With ERDAS software was generated the index image and with SPRING program maps of vegetation, slope and vulnerability. The results show that the simplified model for estimating risk of erosion (vegetation and slope) presents results consistent with field observations and studies that link the main area mapped as high and very high vulnerability, such as area very severe and severe degree desertification Cariri Paraiba. In general, due to the occurrence of flat and smooth relief in 87% of the area, the basin has a low and very low degree of vulnerability in 61.1% of its land. Normal 0 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-ansi-language:PT-BR; mso-fareast-language:PT-BR;} Keywords: Semiarid, vegetation index, remote sensing