Navigating global challenges: development and application of a coupled groundwater and crop growth model

Groundwater is the largest accessible freshwater resource on earth and is critical for people and the environment. In many regions around the world, sectoral water demands exceed the availability of surface water and groundwater is being pumped. Irrigation stands out as the largest groundwater user worldwide, with ca. 40% of current irrigated agriculture relying on groundwater. In many heavily irrigated regions, groundwater abstractions surpass replenishment, resulting in often severely declining groundwater levels. This leads to groundwater depletion, reduced streamflow, drying of wells and springs, land subsidence, saltwater intrusion, and deteriorating surface water quality due to reduced pollutant dilution. In the coming decades, global food demands will increase, driven by a growing world population and socio-economic development. A major challenge lies ahead in how to sustainably ensure sufficient regionally and globally available food. It is inevitable that agriculture will increasingly rely on groundwater to support the required increase in crop production, but the extent to which this groundwater can be extracted sustainably from a quantity and quality perspective is still largely unknown. In this talk, the latest advances in our model development will be presented, focussing specifically on linking groundwater dynamics, surface water interactions, and crop production at both global and regional scales. A specific focus lies on connecting global and regional scales and approaches to better understand the impacts and trade-offs related to global change. In addition, attention will be given to the development of regionally relevant adaptation strategies for sustainable groundwater use worldwide.