Morphometry and trophic state of an urban reservoir: Nado Lagoon, Belo Horizonte, state of Minas Gerais, Brazil

Abstract

This study presents the morphometric characteristics of a small urban reservoir: Nado Lagoon. It is an artificial, shallow lake with 2.7 m. mean depth and 7.6 m. maximum depth. It is located at the bottom of a relatively large valley, surrounded by tall trees, with high relative depth (5.5%) and conical accumulation basin (Dv = 1.07), with a high water column physical stability. The reservoir mean retention time was 78 days during the dry season and 2.1 days during the rainy season. This study also presents the first bathymetric map of the reservoir. The reservoir trophic state was monthly evaluated from September 1999 to September 2000, through Carlson trophic state index (TSI). The results classify the reservoir as meso-eutrophic throughout the sampling period.