The two-dimensional electrical tomography, suitable method for recognizing ‎geological characteristics of flood spreading areas, case study: Heart-Yazd ‎station

In flood water spreading site selection, Electrical resistivity tomography (ERT) plays an essential role in identification of the geological characteristics such as: depth of bedrock, thickness of the alluvial deposits, water table, fault and impermeable layer. ERT methods try to answer some of the important parameters for flood water spreading site selection. ERT method is based on a new approach for modeling distribution of resistivity values under different topographic condition. In this research, ERT studies were designed in a rectangular grid with three profiles in parallel, perpendicular to the channel and the average distance of 600 meters and a length of 1250 meters that covers water spreading and adjacent area. On the profiles, a total of 18 Schlumberger sounding with broadening the AB/2, 100 and 147 meters to 250 meters away from each other were considered. The exact location of the fault was determined by preparation of Two-dimensional cross sections obtained from inverse modeling that were performed with the RES2DINV software. By extraction and interpretation of data which is modeled by SURFER, ver7 and providing pseudo resistivity sections in different depth, type of fault, amount of sedimentary strata displacement and alluvium thickness were determined. By comparing the resistivity values with the existing well logs in the study area, the relative permeability of underlying layers were determined.