Improved understanding of regional groundwater drought development through time series modelling: the 2018–2019 drought in the Netherlands

Abstract. The 2018–2019 drought in north-western and central Europe caused severe damage to a wide range of sectors. It also emphasised the fact that, even countries with temperate climates, adaptations are needed cope increasing future frequencies. A crucial component management strategies is monitor status groundwater resources. However, providing up-to-date assessments regional development remains challenging due limited availability high-quality data. This limits many studies small selections monitoring sites, giving an incomplete image dynamics. In this study, time series modelling-based method for data preparation was developed applied map spatio-temporal south-eastern Netherlands, based on large set evaluated its usefulness reliability validation, simulation, assessment. analysis showed that meteorological extreme throughout breaking 30-year records almost everywhere. Drought onset duration were strongly variable space, higher-elevation areas suffered from well into 2020. Groundwater appeared be governed dominantly by spatial distribution rainfall landscape type. found useful tool enable spatially detailed record development. automated validation improved quality quantity useable data, although optimal parameters probably context dependent. simulations generally reliable; however, use rather than direct measurement can bias estimations, especially at local scale, underestimate variability. Further time-series-based simulation methods, combined accessible consistent will valuable better future.