Análise situacional qualitativa sobre as águas subterrâneas de Fortaleza, Ceará-Brasil como subsídio a gestão dos recursos hídricos

Abstract

This work was conducted in the city of Fortaleza, located in the coastal zone of the northeastern portion of the state of Ceará, northeastern Brazil, covering 314,8 km² and 2.452,18 inhabitants, aimed to analyze the qualitative groundwater in Fortaleza, Ceará - Brazil as a subsidy to Water Resources Management. We collected 120 groundwater samples for physico-chemical analyzes, supplemented with 171 analyzes conducted between 2001-2009 (Data File Hydrogeology Laboratory / UFC). The data were processed with statistical analysis, correlation, identification of depositional environment, ionic relations, classification and framing of ionic water in Ordinance No. 2914/2011 of the Ministry of Health With these data it is concluded that the area is characterized by a reducing environment and acidic / basic with Eh in the range of -0,1 V to 0,2 V and pH between 4 and 9, the relationships ionic rMg+2/rCa+2 and rK+/rNa+, are associated with magnesia silicates and fixation K+ in clay, respectively. Chlorinated water predominate (86% and 81%) and Sodic (67% and 77%). Bacteriological analyzes of 87, 77% of these showed the presence of total coliform and / or fecal. The class of waters for irrigation is predominant C2 - S1 (49 and 73,5%), indicating salinity medium risk and low risk sodium, may be used largely for irrigation of soil and plants salt tolerance. The potential pollution sources identified in the area were building wells without taking up the technical standards of ABNT, cemeteries, inactive dumps, gas station, infiltration of contaminated surface water and lack of basic sanitation in neighborhoods of Fortaleza. Floods in Fortaleza result of the change of land use and occupation of fluvial and lacustrine environments, which coupled with the heaviest rains of the rainy season and concentrated, and not follow the growth of infrastructure and equipment drain at the same rate of growth of city, creates problems of this nature. For the formal insertion of the qualitative aspects of groundwater in vector management of water resources should be based on the fundamentals of Specific Legislation, Environmental Education Program, Watershed Characterization, Registration and diagnosis of wells and finally the management of water.