Land subsidence is a natural hazard that causes gradual settling or sudden sinking of the Earth's surface due to the subsurface movement of earth materials. It is essentially a vertical downward movement of the land surface with little or no horizontal movement and results in loss of surface elevation compared to the surrounding areas. Every year, the phenomenon influences many areas globally causing huge economic, social and environmental losses. It has become a major problem worldwide threatening the viability, sustenance and economic development for millions of people, with total losses amounting to many billions of dollars every year, including the loss of human lives and several menacing environmental damages.