Chap II: Geophysical methods used in Hydrogeology Gravity

Gravity is a secondary geophysical method used in hydrogeology while it is a primary method for hydrocarbon (Oil & Gas). It consist of the measurement in gravitational acceleration changes from location to another and it give information about subsurface density variations that can be related to variations in lithology or moisture (liquid) content. The successful application of the gravity method in groundwater geophysics is documented in many papers, in the last five decades.