Vertical Electrical Sounding (VES) is probably the original electrical method from which all other methods derive. VES is a DC electrical resistivity method usually conducted using one a Schlumberger or Wenner array. These are generally four-electrode arrays with progressively larger spacings between the current and/or potential electrodes. Shorter electrode spacings measure the resistivity distribution in the shallow subsurface, while the longer spacings measure deeper into the subsurface. By taking measurements with an increasing distance between current electrodes, a 1D measurement (sounding) of the resistivity as a function of depth is generated through a modeling process.