Sensoriamento Remoto e Componentes Limnológicos na Caracterização de Lagoas do Pantanal da Nhecolândia, Mato Grosso do Sul

A limnologia aplicada a pesquisas em áreas inundáveis vem crescendo no Brasil. Nesse sentido, esta pesquisa buscou associar dados de sensoriamento remoto e variáveis limnológicas obtidas em campo para distinguir as lagoas no Pantanal da Nhecolândia, região a qual apresenta um sistema lacustre vasto e variado, com lagoas do tipo baías e salinas. Foram coletadas 32 amostras distribuídas em 31 lagoas e um ponto no Rio Negro, ao longo de duas campanhas de campo realizadas em agosto/2012 e setembro/2013, no período de seca do Pantanal. As variáveis estudadas foram: salinidade total (PPT), pH, alcalinidade e dureza. Para a diferenciação das lagoas em baías e salinas, gerouse um banco de dados em ambiente SIG (sistemas de informações geográficas), onde foram associadas as variáveis limnológicas obtidas à imagem do satélite ALOS, sensor AVNIR-2 (IBGE, 2008), na composição falsa-cor R4G2B3. Como resultados, das lagoas amostradas, 20 foram classificadas em baías e 11 em salinas. A utilização das imagens ALOS AVNIR-2 mostraram-se importantes para estudos relacionados à biodiversidade e conservação do Pantanal, por permitirem diferenciar sistemas lacustres no Pantanal e otimizar os trabalhos de campo, que costumam ser dispendiosos em termos de tempo e recursos financeiro

APPLICATION OF AERIAL AND ORBITAL SENSOR PHOTOGRAPHS TO IDENTIFY AND DELINEATE WATER BODIES

Abstract: The application of orbital sensors to identify and delineate water bodies was evaluated in this study. Reference aerial photos were used to measure the surface area of three water bodies in São Gabriel do Oeste, MS, Brazil and assess seven sensors commonly used in environmental studies: ALOS-AVNIR, CBERS 2B-CCD, CBERS 2B-HRC, IRS P6-LISS3, LANDSAT-TM, LANDSAT-ETM+, and LANDSAT-OLI. The images were analyzed with the near infrared (NIR) band, and digital processing techniques including image fusion (spatial enhancement), false-color composition, and pre-processed radiometric correction were applied to some sensors. Image fusion and radiometric correction were applied to three sensors; only color composition was not conducted on the HRC sensor. In all water bodies analyzed, images from the CCD sensor showed the greatest values of imprecision, reaching 192% for Water Body #3 without digital processing. Considering the spectral properties of the NIR band, we expected more precise data from the analyses using this spectral range. However, color composite analyses obtained greater percent precision compared with analyses that only used the NIR band

APPLICATION OF AERIAL AND ORBITAL SENSOR PHOTOGRAPHS TO IDENTIFY AND DELINEATE WATER BODIES

<div><p>Abstract: The application of orbital sensors to identify and delineate water bodies was evaluated in this study. Reference aerial photos were used to measure the surface area of three water bodies in São Gabriel do Oeste, MS, Brazil and assess seven sensors commonly used in environmental studies: ALOS-AVNIR, CBERS 2B-CCD, CBERS 2B-HRC, IRS P6-LISS3, LANDSAT-TM, LANDSAT-ETM+, and LANDSAT-OLI. The images were analyzed with the near infrared (NIR) band, and digital processing techniques including image fusion (spatial enhancement), false-color composition, and pre-processed radiometric correction were applied to some sensors. Image fusion and radiometric correction were applied to three sensors; only color composition was not conducted on the HRC sensor. In all water bodies analyzed, images from the CCD sensor showed the greatest values of imprecision, reaching 192% for Water Body #3 without digital processing. Considering the spectral properties of the NIR band, we expected more precise data from the analyses using this spectral range. However, color composite analyses obtained greater percent precision compared with analyses that only used the NIR band.</p></div