The 2019 Henry Darcy Medal is awarded to Petra Döll for groundbreaking work in global freshwater system modelling, increasing awareness of threats to freshwater resources in the world, and contributions to participatory water management.
Petra Döll significantly advanced the global modelling of water resources through the global hydrological model that she developed. With this model, she improved our understanding and awareness of water problems at the global scale, for instance by generating the first global map of groundwater recharge and one of the earliest maps of global water scarcity that considered environmental flows. Döll has an extraordinary eye for detail given the scale of her model. Her team continually compares the results of their models with ground-based data in various basins globally to validate their results and are integrating detailed process understanding into their models. Her work has led to clear and very valuable progress in the development of strategies and concepts for the sustainable use of global water resources, as illustrated by her team’s assessment of more sustainable practices for irrigated agriculture by linking water availability to crop production through modelled irrigation. She was one of the first to investigate ecologically relevant streamflow regime alterations by human water use, dams, and groundwater depletion at a global scale.
In support of her own modelling work and that of others, Döll developed various freshwater-related global datasets, including irrigation maps, river networks, and dam and wetland databases, that are used by many colleagues. She pioneered linkages between global modelling and remote sensing data products, thereby greatly improving data availability for hydrological modelling, which helps constraining uncertainties in model output.
Döll was instrumental in the creation of a range of global freshwater-related projections and assessments for various future horizons and different scenarios, grounded in a state-of-the-art scientific basis. These include the UN World Water Development Reports, the Millennium Ecosystem Assessment, and the UN Global Environmental Outlooks. She was a contributing and lead author of the chapters on freshwater resources and their management in the three latest reports of the International Panel on Climate Change (IPCC) in which she synthesised our integrated knowledge of climate change impacts on freshwater systems. The IPCC was awarded the Nobel Peace Prize in 2007 for these reports.
Döll also made lasting contributions to water management through the development and application of new ways to take into account problem perspectives of stakeholders into participatory water management in the problems related to water quality. She investigated the optimal design of trans-disciplinary knowledge integration processes to improve management of complex social-ecological systems. She also developed integrated qualitative-quantitative scenarios in support of sustainable water management. To do so, she bridged disciplines and collaborated with colleagues from fields ranging from engineering to social sciences, and involved local actors and stakeholders in the process. Döll’s demonstrated talents allow her to synthesize and evaluate knowledge about freshwater systems such that it can meaningfully support stakeholder decisions that will help societies to adapt to climate change and mitigate its effects.