Job description
As part of the ERC Advanced Grant project GEOWAT, we are looking for an enthusiastic Postdoc candidate who is interested in state-of-the-art global hydrology and groundwater modelling. You have an interest in global water and sustainability challenges and are enthusiastic about working with large datasets and numerical models. You are a team player and will be part of a multidisciplinary team of two postdocs, 3 PhD students, scientific and support staff. Together, you will work to assess the global volumes of fresh groundwater that are technically and economically attainable for human water use and investigate how these volumes can be extracted in a sustainable manner.
As a Postdoc you will start by setting up a 30 arcsecond (~1km) global hydrological model based on our inhouse global hydrology and water resources model PCR-GLOBWB. You will build upon already existing 30 arc-second models for Europe and Africa. Next, you will extend our existing two-layer 30 arc-second global groundwater model GM-GLOB1k by including an improved global hydrogeological parameterization that will be developed by a second postdoc hired in the project. You will work closely together with this postdoc. Finally, for the coastal areas, you will add the ability to simulate groundwater salinity. When setting up the models in a high-performance computing environment, you will be assisted by a scientific model technician The underlying model codes (PCR-GLOBWB and GM-GLOB1k) have already been made computationally efficient in previous projects. Thus, the challenge of this work will be on parameterizing, tuning and validating the models at the global scale. The coupled surface water-groundwater model and hydrogeological schematization developed by the two postdocs will subsequently be used by the PhDs (starting 6 months and 1 year later) to assess the physical, economic and ecological limits to groundwater use. You will assist and supervise the PhDs in the use of the global models. You will write papers about the model development for scientific journals and you will also be asked to contribute as co-author to papers on sustainable groundwater use that will be written by the PhDs.
About the ERC AdG project GEOWAT
GEOWAT stands for “The Global Assessment of the Limits of Groundwater Use”. It is a 2.5 million 5-year research project funded by the European Research Council under the Advanced Grant scheme.
Summary of the GEOWAT project
Population growth and economic development have dramatically increased the demand for food and water. The resulting expansion of agriculture into areas with limited precipitation and surface water has greatly increased the reliance on groundwater irrigation. Further, urban groundwater use has risen exponentially to meet the ever-increasing population growth of mega-cities. These trends have resulted in a dramatic rise in groundwater pumping and associated high rates of aquifer depletion around the globe. The depletion of our world’s aquifers is unsustainable and will eventually impact the food security of future generations. Also, groundwater depletion results in severe environmental impacts such as land subsidence, groundwater salinisation, and damage to groundwater-dependent ecosystems. Despite decades of research on groundwater overuse, knowledge on attainable groundwater reserves and the critical time horizons of their depletion is completely lacking. GEOWAT takes the giant leap to extractable volumes and depletion horizons by answering the obvious question that has been avoided thus far: How much groundwater is there and how long will it last? To this end, GEOWAT will build the first high-resolution global groundwater model supported with a 3D-mapping of the world’s aquifers. GEOWAT will use these unique modelling tools, in combination with dedicated case studies, to assess, for the first time, the global volume of physically and economically extractable fresh groundwater, and determine the time to physical and economic depletion under future pumping. It will also provide the first global assessment of the effects of groundwater pumping on groundwater-dependent ecosystems and explore pathways to sustainable groundwater use. As such, GEOWAT will provide critically-needed new knowledge to address one of most pressing challenges that mankind will face: how to sustainably manage the freshwater resources needed to survive on this planet?
GEOWAT’s Research design
GEOWAT is organised into six inter-related work packages (WPs) executed by six scientists (including the PI), a research assistant and one model engineer. The backbone of the research approach (WP1 – This postdoc 1) is the creation of a high-resolution 30 arc-second (~1 km) physically-based, global-scale surface water - groundwater model (GLAM). To support this model, we will develop a 30 arc-second hydrogeological schematisation (HYGS) of the world’s aquifers that consists of aquifer and aquitard thicknesses and their hydraulic properties. The HYGS will use a novel combination of new and existing global datasets, machine learning and data-assimilation (WP2 – Postdoc 2). The GLAM and HYGS will then be used to address the key scientific objectives: to estimate past, current, and future volumes of fresh groundwater globally (physical limits, WP4; PhD1); to assess the volume of groundwater that can be extracted, including costs and benefits and assess pathways to sustainable use (economic limits, WP5; PhD2); and to assess how extraction strategies impact the extent and biodiversity of groundwater-dependent ecosystems (ecological limits, WP6; PhD3). The results of all WPs will be synthesised into one multi-faceted assessment of the limits of groundwater use. To assess the accuracy of these results, we will use three-pillar strategy: a) global analyses will be grounded on regional case studies in four depletion hotspots (WP3); b) results will be evaluated against hydrogeological datasets, including regional groundwater models; c) uncertainty assessment will be integral to our approach, including all relevant sources of uncertainty.