Integrated Electrical Probe Chad Gill Maya International Airport Water-rich Belt Approach And Its Application

Chad Gill Maya International Airport proposed site is located on the southeast edge of the Lake Chad Basin, Region Lasade, hydrogeological conditions of the Lake Chad basin is mainly controlled by the low-lying, phase sticky soil strata and Quaternary fluvial sand deposits in the lake cross, the underlying Cretaceous shale, regional water scarcity, and no nearby wells construction experience to follow, to understand the regional hydrogeological conditions, construction in the water near the first hole of a hydrogeological investigation, and construction of a test well (Dakoulunas) by pumping test, the water can not meet the design requirements.The geological characteristics of the area known, the area basically Quaternary sand deposition, surface to Quaternary silt, clay soil the main part of the lot in sand development, there are some sections of the grit.By hydrology and water well survey, underwater sand latent regional main aquifers, based on this, the first of a large part of the known water wells and test wells planned airport with high density electrical resistivity profiles and DC sounding work, we have made hydro-geophysical exploration well known anomaly; Then near the airport and in the vicinity of the proposed refinery in N'Djamena, high density cross-section and DC electrical resistivity sounding field of construction, based on a high-density electrical profiles and DC resistivity sounding data comprehensive analysis, concluded that the many high resistance aquifer (water-rich belt). In which the proposed airport near the well known test inferred a WNW-trending belt-rich water, The sand belt in a high density profile control range of more than 900 meters long and a width of 180m. After verification by laying a plurality of wells, conduct electrical logging pumping test conducted to verify that the tape is a better distribution of the sand near the proposed airport is relatively water-rich area, for the establishment of water production wells group, and achieved the expected results.Through this study demonstrate the integrated electrical method as an indirect method for groundwater exploration, lack of engineering experience in Chad area, which can effectively summarize the regional hydrogeology law in hydrogeology based on the integrated electricity law as a means to effectively avoid blind drilling work mistakes, lack of hydrogeological data for Chad and the wider expanse of Africa region, the use of integrated electrical technical methods to detect water-rich belt, can find water achieved a multiplier effect.