Anthropogenic activities alter drought termination

Abstract

Despite the increasing influence of human activities on water resources in our current Anthropocene era, the impacts of these activities on the duration, rate and timing of the recovery of drought events, known as the drought termination phase, remain unknown. Here, we present the first assessment of how different human activities (i.e. water abstractions, reservoirs, water transfers) affect drought termination. Six case studies in Europe were used to analyse the human influence on streamflow drought termination characteristics. For all case studies, we compared the drought and drought termination characteristics derived from a human-influenced time series of streamflow (observation data) and a naturalised time series (modelled data) for the same period. Overall, results clearly demonstrate the influence of human activities on drought terminations in all the studied catchments. Groundwater abstractions, reservoirs and mixed influences were all found to increase the average duration of drought termination, whereas water transfers into the catchment decreased drought termination duration. Results also show that average drought termination rates increased in all case studies due to the human influence. Furthermore, start and end months of the termination phase were more skewed to certain months in human-influenced data than in the naturalised situation. Future research could extend this new knowledge by looking to add further case studies and covering different human activities to gain a wider understanding on how human actions modify hydrological droughts and their recovery. Furthering this work could also help to improve the forecasting of drought recovery in the Anthropocene, which is important for informing drought management decisions.

Spatiotemporal development of the 2018–2019 groundwater drought in the Netherlands: a data-based approach

“…Both the short-term and structural deviations can result from errors, such as instrument drift and typing errors. However, deviations can also reflect real groundwater behaviour caused by local natural or human influences, such as rainstorms, flooding or abstraction (Post and von Asmuth, 2013;Zaadnoordijk et al, 2019;Margariti et al, 2019). For one subregion of the study area (Overijssel province, see Fig.…”

“…Multiple recent research efforts have aimed at better understanding the variations in groundwater drought and its impacts at national and European scales (Bakke et al, 2020;Bloomfield et al, 2018;Hellwig et al, 2020;Margariti et al, 2019;Van Loon et al, 2017). The 2018 drought in Europe has so far been mainly studied from a meteorological perspective (Bakke et al, 2020;Philip et al, 2020;Toreti et al, 2019).…”

“…These simulations often have a very good fit to the data (Bakker and Schaars, 2019;Zaadnoordijk et al, 2019); however, this approach inevitably also strips out part of the external influences that are not explicitly included in the model drivers (Peterson et al, 2018;Zaadnoordijk et al, 2019). Drought occurrence and development can be strongly affected by human impacts, as well as by local-scale natural influences such as surface water influence (Margariti et al, 2019;Van den Eertwegh et al, 2019). As such, excluding such external drivers of groundwater levels may provide an incomplete image of drought dynamics (Van Loon et al, 2016).…”

Drought: Progress in broadening its understanding

“…Hence, incorporating forest legacy effects into climate–carbon cycle models are important for capturing the effects of drought in carbon cycling (Anderegg et al, ; van der Molen et al, ). Furthermore, in the human‐modified world, the increased influence of anthropogenic activities is affecting drought termination phases (Margariti et al, ). Human activities including water abstractions, reservoirs, and water transfers are affecting the duration, rate, and recovery time of drought events (Margariti et al, ; Schwalm et al, ).…”

“…Furthermore, in the human‐modified world, the increased influence of anthropogenic activities is affecting drought termination phases (Margariti et al, ). Human activities including water abstractions, reservoirs, and water transfers are affecting the duration, rate, and recovery time of drought events (Margariti et al, ; Schwalm et al, ). Hence, drought recovery forecasting is important for improving drought management decisions in the Anthropocene.…”