Determinação do parâmetro de intersecção de fraturas para o Aqüífero Atuba

Abstract

Fracture cross-point determination to the Atuba Aquifer. Based on the structural model proposed by Chavez-Kus (2003) and Chavez-Kus & Salamuni (2008), σ 1 was oriented in the N-S direction in the region of Curitiba. In this context, the calculations of lineament crosspoint were accomplished through the scripts developed by Kim (2004) and Kim et al. (2004). Only fractures that are most favourable for groundwa- ter exploitation (N45W N45E) were considered. The obtained result indicates that intersection parameters in the crossings of conjugate and hybrid fractures coincide with high specific capacities and water flow rates of deep wells. The master faults, which control the geometry of the top of the basement of the Atuba Complex, are always present where high values of lineament crosspoint occur. The Belem fault shows the highest coin- cidence at crossing points with other structures. The hydraulic properties of the geological media in this area, and through this, the productivity of pumping wells, cannot only be estimated due to the proximity to local lineaments. In fact, fracture density does not correlate well with the productivity of the wells. The crosspoint fracture parameter, calculated through the extension Lineament Analysis, shows the best correlation to ground- water favourability.The obtained results illustrate that the identification of areas favourable for the circulation of groundwater is possible, when the calculation is made based on the most recent tectonic events.