Evaluating water resource maintenance for lakes of the middle Doce river / Avaliação da manutenção dos recursos hídricos dos lagos do médio rio Doce

The importance of water resources to mankind and the threat level these resources have withstood due to regional and worldwide human intervention are undeniable. In the middle stretch of the Doce river basin, there are close to 170 natural lakes, located between an environmental conservation area and monoculture eucalyptus plantations, with social, economic and biological importance. Our objective was to evaluate whether the water surface area in these lakes has remained constant in the last few decades, and make inferences on the result. To that end, we measured the water surface area of 16 lakes, from satellite images obtained between May and August in the years 1977, 1979, 1981, 2000 and 2005. Total water surface area was compared considering these dates the two different areas. We did not find any changes in water surface area for these lakes in the studied images. Likewise, we did not observe reductions in any single lake for any of the studied areas. These results indicate hydrological constancy of the system, as well as of the services this group of lakes provides to society and biodiversity in its vicinity, regardless of whether the environmental matrix consists of old-growth vegetation or eucalyptus plantations.

É inegável a importância dos recursos hídricos ao Homem e o grau de ameaça que vêm sofrendo devido a intervenções humanas regionais e globais. No trecho médio da bacia do rio Doce há cerca de 170 lagos naturais, distribuídos entre área de conservação ambiental e área de monocultivo de eucalipto, com importância social, econômica e biológica. O nosso objetivo foi avaliar se a lâmina d'água total destes lagos vem se mantendo nas últimas décadas e inferir sobre esta resposta. Para isto, aferimos a lâmina d'água de 16 lagos a partir de imagens de satélite obtidas entre maio e agosto dos anos de 1977, 1979, 1981, 2000 e 2005. Esta lâmina d'água total foi comparada considerando estas datas e as duas áreas diferentes. Não encontramos alteração na lâmina d'água destes lagos nas imagens estudadas. Do mesmo modo, não observamos redução em lagos de quaisquer das áreas estudadas, isoladamente. Estes resultados apontam para uma constância hidrológica do sistema, bem como dos serviços que este conjunto de lagos presta à sociedade e à biodiversidade de seu entorno, independente da matriz ambiental ser constituída por vegetação conservada ou cultivo de eucalipto.

Evaluating water resource maintenance for lakes of the middle Doce river - doi: 10.4025/actascibiolsci.v34i3.8703

The importance of water resources to mankind and the threat level these resources have withstood due to regional and worldwide human intervention are undeniable. In the middle stretch of the Doce river basin, there are close to 170 natural lakes, located between an environmental conservation area and monoculture eucalyptus plantations, with social, economic and biological importance. Our objective was to evaluate whether the water surface area in these lakes has remained constant in the last few decades, and make inferences on the result. To that end, we measured the water surface area of 16 lakes, from satellite images obtained between May and August in the years 1977, 1979, 1981, 2000 and 2005. Total water surface area was compared considering these dates the two different areas. We did not find any changes in water surface area for these lakes in the studied images. Likewise, we did not observe reductions in any single lake for any of the studied areas. These results indicate hydrological constancy of the system, as well as of the services this group of lakes provides to society and biodiversity in its vicinity, regardless of whether the environmental matrix consists of old-growth vegetation or eucalyptus plantations.