Condições físico-químicas e biológicas em águas superficiais do Rio Tapajós e a conservação de Floresta Nacional na Amazônia, Brasil

Abstract

The Amazon Basin has a large amount of water that must be conserved to meet the needs of this and future generations. This study evaluated evidence of the effects of human disturbance in the Tapajos National Forest and its surroundings using physicochemical and biological variables in surface waters as indicators. In order to accomplish this, we first analyzed the data series of precipitation in the region. Samples were collected from the Tapajos River in areas influenced by land use and occupation. We made on-site assessments and collected samples for laboratory analysis. Rainfall in December 2012 was higher than the climatology indicated. The results of the Water Quality Index (WQI) indicated the predominance of the "good" to "great"; its values ranged between 70 < WQI < 90 and 90 < WQI ≤ 100, in 70.0 % of the samples collected. The balnearies Alter do Chão and Pindobal had the highest levels of fecal coliform, possibly due to anthropogenic effects that could be mitigated by adequate tourist practices. The highest WQI and greater transparency of the water near Tauari, showed minimal effects of human activities in nearby surface waters. It is concluded that water bodies are sensitive to changes in land use and those changes may threaten the maintenance of conservation areas.

Análise das relações entre uso do solo e qualidade da água do Lago Bonsucesso, em Jataí, Estado de Goiás, Brasil (Analysis of the relations between the land use and quality of the water of Bonsucesso Lake, in Jataí, Goiás State, Brazil)

“…Valores abaixo dos observados no Lago Bonsucesso foram encontrados por Batalha et al (2014) em um estudo no rio Tapajós (AM), no qual os resultados variaram de 5,33 a 6,03. De acordo com os autores esse resultado abaixo da neutralidade, tendendo à acidez, pode ser atribuído à decomposição de matéria orgânica que influencia a acidez natural das águas.…”

Fertilidad natural de los suelos aluviales en la Amazonía

“…O termo "terra firme" designa terras não inundadas pelos rios, compostas por solos minerais não submetidos a processos hidromórficos. Para os ecossistemas das "várzeas", as áreas estão sujeitas a inundações periódicas, ocasionadas pelos rios de águas brancas, na época das cheias (Sioli, 1951;Sioli, 1984;Junk et al, 2011;Alves Batalha et al, 2014).…”

“…Geologicamente, as várzeas podem ser divididas em duas; as formadas no Pleistoceno, (cerca de 18.000 anos) e as formadas no Holoceno (cerca de 5.000 anos). Os ecossistemas de várzea na Bacia Amazônica representam uma área de aproximadamente 200.000 km 2 (Salati et al, 1983;(Alves Batalha et al, 2014;Furch, 2000;Villacis Fajardo et al, 2009). As várzeas Holocênicas são mais jovens e possuem os solos mais férteis de toda a Amazônia, dada à deposição periódica de sedimentos resultante das inundações anuais, formando regularmente uma camada nova de sedimentos proveniente dos Andes (Irion, 1984;Teíxeíra et al, 2018).…”

Water Quality in Micro-watersheds Under Different Land Uses in the Municipality of Alegre, Espírito Santo

“…Several variables are used in water quality studies, necessitating a technical synthesis of the data via the Water Quality Index (WQI), which is widely used in Brazil and provides information that is more accessible and comprehensible for the general public (Almeida & Schwarzbold, 2003;ANA, 2014;Von Sperling, 2005). The Index was created by the National Sanitation Foundation and adapted by the Environmental Company of the state of São Paulo, and has been used by sanitation companies and studies related to water monitoring and quality diagnostics such as the one by Batalha et al (2014).…”