Detecting and modelling the evaporate dome in a dam site using microgravity data

A microgravity survey was carried out at a dam site with a hilly topography inside the microgravity network and a rough terrain in the surrounding area for mapping the evaporate dome. After applying Earth tide, free-air and Bouguer corrections, the Bouguer gravity anomalies were computed. Using the polynomial fitting approach, the residual gravity anomalies were obtained. Several relative negative anomalies were distinguishable in the residual map. Rough estimations of the minimum and maximum depths of these anomalies were provided by Euler de-convolution and upward continuation methods. These anomalies were modelled by the three-dimensional (3D) inversion method.