Global Mapping of Groundwater Recharge and Sustainable Aquifer Water Withdrawals Using Satellite Observations

Faculty Lead: Dara Entekhabi, Bacardi and Stockholm Water Foundations Chair; Professor of Civil and Environmental Engineering; Professor of Earth, Atmospheric and Planetary Sciences

Aquifers are widely used in irrigated agriculture for food production. These subsurface natural reservoirs are tapped into by pumping wells that withdraw water for irrigation. The aquifers are replenished with the recharge hydrologic flux which is the vertical flow of water in the near surface soil where precipitation enters the soil. Thus, the natural rate of recharge flux is indeed the sustainable rate of groundwater use. Important as this flux is, there is no systematic mapping of it. There are no in situ instruments that can be widely deployed to map recharge. While isotopes of water are often used to estimate recharge at a field site, this approach is expensive and labor intensive. Aquifers around the world are being woefully over-exploited. To manage and restore them, we need mapped estimates of recharge. This project aims to provide global groundwater recharge maps using NASA’s Soil Moisture Active Passive (SMAP) satellite data. Our approach combines satellite measurements with precipitation data and land surface models to develop reliable methods for estimating groundwater recharge globally. This research will provide insights and tools for sustainable groundwater management, supporting effective policy-making and strategic planning to ensure water security in the face of climate change. Our research emphasizes global applicability, demonstrating how a better understanding of groundwater recharge can inform sustainable management practices worldwide.