1. The geographic area or watershed from which water flows into a river, stream, or other water body
The tributary area of the Amazon River covers millions of square kilometers.
A área afluente do Rio Amazonas cobre milhões de quilômetros quadrados.
2. In hydrology, the drainage basin or catchment area that feeds water to a main watercourse
Engineers calculated the tributary area to determine water flow capacity.
Os engenheiros calcularam a área afluente para determinar a capacidade de fluxo de água.