Mapping Global Subsidence and Its Impacts Due to Groundwater Depletion
Abstract: Groundwater demand owing to rapid urbanization and irrigation-agriculture land uses is increasingly depleting aquifers worldwide leading to prevalent aquifer-system compaction and land subsidence. Even though land subsidence is currently impacting many urban and agricultural areas around the world, its global extent is poorly known. We estimated that subsidence hazard due to groundwater depletion affects 2.2 million km2 of land, threatens 1.2 billion inhabitants and has an exposed GDP of US$ 8.2 trillion. During this century, prolonged drought periods will increase groundwater depletion and subsidence impact worldwide, threatening 1.6 billion inhabitants in 2040. These findings are crucial to informing good governance practices aimed at ensuring the future sustainability of groundwater resources and reducing subsidence impacts worldwide, especially in coastal areas where subsidence contributes significantly to relative sea-level rise.
Biography: Dr. Gerardo Herrera is a Research Professor at the IGME – CSIC. He founded the Geohazards INSAR laboratory and Modelling group in the Geological Survey of Spain (IGME-CSIC), former director of the Earth Observation and Geohazards at the Geological Surveys of Europe, national representative in the Land Subsidence International Initiative from UNESCO. His research topics include mapping landslides and subsidence phenomena; monitoring terrain motion through multi-sensor radar satellites and ground-based SAR systems; numerical modelling of landslides and subsidence: susceptibility, hazard and risk.