O Índice do estado trófico e sua adaptação para os sistemas lênticos do semiárido cearense

Abstract

To meet the water shortage, Ceará has an extensive network of artificial reservoirs intended for various uses. However, waters that remain reserved in dams present limnological vulnerability, and the phenomenon of eutrophication is one of the worst consequences of anthropic activities developed in the areas of contribution of these reservoirs, consequences that are aggravated due to the natural characteristics of semiarid, an environment marked by low rainfall and its poor distribution in space and time. To assist the trophic study of these waters, it has long been used by limnologists a tool to classify water resources in relation to their trophic state, the TSI - the Trophic State Index, developed by Carlson (1977). The research conducted here was to enhance the study of the correlation among the parameters of chlorophyll a, total phosphorus, and Secchi Transparency, used in the composition of the TSI, as well as to adjust the logarithmic scale of the index, according to Secchi's maximum and mi nimum measures to the water reservoirs of Ceará, which resulted in a trophic classification methodology adapted to the conditions of the inserted lentic systems in Ceará semiarid