2D and 3D modeling of resistivity and chargeability to identify the type of saturated groundwater for complex sedimentary facies

Determining the type and properties of saturated groundwater for complex sedimentary
facies, as well as the various properties of these sedimentary facies, requires extensive geological,
hydrogeological, and geophysical studies. Therefore, identifying the different types of subsurface
deposits and their physical properties as well as their geological, hydrogeological, and structural
se􀁂ings are the interesting features in this study which play an important role in achieving its
objectives. To achieve these objectives, the Direct Current (DC) resistivity method and the Direct
Current Time-Domain Induced Polarization (DC-TDIP) method were used. These two methods
were applied because they are complementary methods, one of which is more accurate in sediments
saturated with fresh water (the DC resistivity method) and the other in sediments saturated with
salt water (DC-TDIP method). Also, the DC-TDIP method was applied to avoid ambiguity in the
resistivity results, as well as their results were compared with the available geological and
hydrogeological field data. Accordingly, 2D and 3D resistivity values were designed to describe the
hydro-lithological environment of the recorded sediments, and their hydrogeoelectric properties
and groundwater zones were also identified and divided. Also, 2D and 3D chargeability values were
designed to distinguish between sediments, their depositional facies, and their saturated water
properties. These values also succeeded in separating clay from non-clay layers, and clay layers
from layers containing salt water. Therefore, it was found that the integration between the two
methods helped in identifying and visualizing the characteristics of the sediments and determining
their facies and their water content, which helped in understanding the complex sedimentary facies
recorded in the study area as well as identifying the types and characteristics of groundwater
contained in these facies. Therefore, it can be recommended to apply the previous methodology and
include the two geophysical methods and their results to study complex facies deposits and
determine their water content and type, especially in similar depositional environments that are
located next to a source of salt water mixed with other types of water.