Monitoramento por sensoriamento remoto da concentração de clorofila-a e das florações de cianobactérias no Baixo Tapajós : audiovisual praias do Tapajós para gerações presentes e futuras

Abstract

The Tapajós River is the fifth largest river in the Amazon Basin. From Aveiro to Santarém, it resembles a lake and favors the eutrophication process. It is under pressure such as: deforestation, gold mining, use as a waterway and tourism. The beaches between Santarém and Belterra, gained evidence when in 2009 the newspaper The Guardian, chose Alter do Chão as the best beach in Brazil. The growth of tourist activities and infrastructure was notable. In 2015 after bathing water quality analyzes, Alter do Chão was banned. The increase in planktonic blooms has been observed by popular researchers since the 1990s. Extending the studies, 2450 km2 of remote sensing was monitored from Aveiro to Santarém, obtaining the blooming areas of cyanobacteria, concentrations of chlorophyll-a, nutrient pollution and risk levels for contact activities. The occurrence of cyanobacteria is linked to variations in rainfall and river level. The greatest health risks occur at the maximum points of drought in November and flooding in May. The areas with the highest occurrence of blooms and the highest concentrations of chlorophyll-a are upstream from the beaches of intense use. The increase in human activities and the occupation of the soil, may be responsible for the increase in flowering. This information must be disseminated through a didactic-informative product for Basic Education. An audiovisual was produced for application in Basic Education called “Praias do Tapajós For Present and Future Generations”, as the time of 23’16” divided into 07 blocks related to the researched content. The audiovisual was applied in six classes of two schools of basic education, in the High School, being one in Belém the Federal Institute of Pará and another in Santarém the São Raimundo Nonato State School, totaling eleven hours of application. The audiovisual product was validated through a 'likert' questionnaire, observing conceptual points related to the acquired knowledge, relationship with studied contents, involvement in environmental issues and quality of the material presented. The average rejection rates were always below 25% while approval was always above 75%.