formation of a deep pit lake: case study of Aguas claras,Brazil

the paper presents the case study of the current formation of brazilian pit lake from an iron ore mininig activity.the water used for the filing of the lake comes from rain,ground water and the complementary pumpage from a close river.at its final stage,which will be reached around year 2018,lake Aguas claras will have a surface area of 0.67 Km2 and the depth of 234m,which will make it the deepest lake in the country.the filing of the lake began in the year 2001 and a monthly monitoring programme (physical,chemical and bioogical characteristics) is snce then in co course the analyses show taht lake Aguas claras , presents a very good water quality (well oxygenated.low valuse of colour and tubidity,limited degree of mineralization , PH slightly alkaline,low nutrient concentrations,excellent bacteiological conditions), together with a remarkable shift in the dominance of phytoplanktonic groups,indicating the high instability of lakes tat are undergoing a process of formation.one relevant point in the managment of this valuable water resource is to create adequate conditions for the protection of the aquatic environment considering the very probable maintenance of these favourable charateristics in future years,the possible uses of the lake will be directed to recreation (swimming,diving,sailing,saling and fishing),amenity value and water supply.

کلیدواژه ها:

mine dewatering ، pit lake ، water quality ، water uses