Produção Nacional
O Sistema Aqüífero Urucuia
2007; Sociedade Brasileira de Geologia; Volume: 37; Issue: S4 Linguagem: Inglês
10.25249/0375-7536.200737s4216226
ISSN2177-4382
AutoresMárcia Tereza Pantoja Gaspar, José Elói Guimarães Campos,
Tópico(s)Groundwater and Watershed Analysis
ResumoThe Urucuia Aquifer System (UAS) represents an association of groundwater reservoirs developed in Upper Cretaceous fluvial aeolian sandstones of the Urucuia Group, Sanfranciscana Basin, the main Phanerozoic coverage of the São Francisco craton. This aquifer system extends for about 76,000 km² from the south of Piauí state up to the northwest region of Minas Gerais state, but the major expression in area is related to the west of Bahia state. It presents a longitudinal axis that separates the groundwater regional flow to west (Tocantins hydrographic basin) and east (São Francisco basin). Westward of the divisor there is a fast fall of the potentiometric surface, characterized by the presence of deep static levels. The available data allow defining four subtypes of aquifers in the UAS: regional unconfined aquifer, local perched aquifer, confined aquifer, and deep unconfined aquifer. The presence of silicified levels, grain size variations of the sandstones and the geographic and space position are the main controlling parameters of the presence of these subtypes in the system. The hydrodynamic parameters are: specific capacity of the wells up to 17.2 m³/h/m, transmissivity of 10-2 to 10-5 m²/s, hydraulic conductivity of 10-5 to 10-7 m/s, storage coefficient of 10-4 (confined aquifer) to 10-1 (unconfined aquifer). The permanent water reserve has been estimated of 3.77∙1012 m³, while the regulating reserves are about 30.78∙109 m³/year.
Referência(s)