Northeastern Brazil Groundwater Project

Ground Geophysics

In an effort to improve groundwater exploration and management in northeast Brazil, including increasing the success rate of drilling productive water wells, the Canadian and Brazilian Geological Surveys have initiated a multi-year cooperation project, supported by the Canadian International Development Agency (CIDA). The project involves the transfer of technologies and know-how from Canada in such areas as geophysics, groundwater modeling of fractured and porous media, aquifer recharge technology, groundwater geochemistry including research on the problem of groundwater salinity, etc. The project was ratified in April 2000; the Ground Geophysical Mission described in this page was carried out in June 2000 and has the distinction of being the first technical mission of the program.

The main purpose of the mission was:

To improve the capacity of local institutions to use ground geophysical techniques to investigate factors that affect the groundwater supply (e.g. location of aquifers, water quality, flow rate, etc.) in selected areas of northeastern Brazil;
To help select pilot areas for future groundwater mapping surveys by airborne geophysical methods, and to organize the collection of ground orientation data that will be needed for interpreting the airborne survey data;
To help plan the geophysical component of the Northeastern Brazil Groundwater Project by recommending additional activities in which Canadian technologies and specialists may have an input.

Ground geophysical field work was conducted in the three states that are involved in PROASNE, Ceará, Pernambuco and Rio Grande do Norte, to help with the selection of appropriate pilot areas over which to conduct airborne electromagnetic surveys, and to provide data useful for the airborne survey design and interpretation. Ground surveys were specifically conducted to determine the contrasts in electrical conductivity between basement rock, saturated fractured rock and thin alluvial cover, and the magnitude of geophysical anomalies that might be expected from target structures.

One of the outcomes of this exercise was the selection of three pilot areas, about 100 km² each, in which airborne geophysical surveys were carried out in March and April 2001. These three pilot areas, plus a fourth one in the municipality of Caraúbas/RN, remained the main focus areas for all of PROASNE's technology transfer and social/gender activities throughout the project.

The complete mission report by the Canadian consultant, Komex International Ltd. of Calgary is available online, as are other reports in Portuguese by PROASNE partners UFRN and CPRM.

Selection of photographs from the June 2000
Ground Geophysical Mission to NE-Brazil

click photo to enlarge and for caption