Future discharge drought across climate regions around the world modelled with a synthetic hydrological modelling approach forced by three general circulation models

Abstract

Abstract. Hydrological drought characteristics (drought in groundwater and streamflow) likely will change in the 21st century as a result of climate change. The magnitude and directionality of these changes and their dependency on climatology and catchment characteristics, however, is uncertain. In this study a conceptual hydrological model was forced by downscaled and bias-corrected outcome from three general circulation models for the SRES A2 emission scenario (GCM forced models), and the WATCH Forcing Data set (reference model). The threshold level method was applied to investigate drought occurrence, duration and severity. Results for the control period show that the drought characteristics of each GCM forced model reasonably agree with the reference model for most of the climate types, suggesting that the climate models' results after post-processing produce realistic outcomes for global drought analyses. For the near future (2021-2050) and far future (2071-2100) the GCM forced models show a decrease in drought occurrence for all major climates around the world and increase of both average drought duration and deficit volume of the remaining drought events. The largest decrease in hydrological drought occurrence is expected in cold (D) climates where global warming results in a decreased length of the snow season and an increased precipitation. In the dry (B) climates the smallest decrease in drought occurrence is expected to occur, which probably will lead to even more severe water scarcity. However, in the extreme climate regions (desert and polar), the drought analysis for the control period showed that projections of hydrological drought characteristics are most uncertain. On a global scale the increase in hydrological drought duration and severity in multiple regions will lead to a higher impact of drought events, which should motivate water resource managers to timely anticipate the increased risk of more severe drought in groundwater and streamflow and to design pro-active measures.

Human–water interface in hydrological modelling: current status and future directions

“…LPJmL Konzmann et al, 2013), JULES flood induced by climate extremes (e.g. Milly et al, 2005;Hirabayashi et al, 2013;Orlowsky and Seneviratne, 2013;Dankers et al, 2014;Jongman et al, 2014;Prudhomme et al, 2014;Sheffield and Wood, 2008;van Huijgevoort et al, 2014;Wanders and van Lanen, 2015;Wanders and Wada, 2015b); however, human water management is found to be an important factor affecting regional water supply and hydrological variability (Wada et al, 2013a, b;Di Baldassarre et al, 2017). Recent studies explicitly model human interventions (e.g.…”

“…The model simulations were used to derive locally the 90th percentile variable threshold, which has been used to calculate the AID aggregated to the state level for each hydrological variable of soil moisture, groundwater, and river discharge. The 90th percentile threshold has commonly been used in drought identification (Wada et al, 2013a, b;Wanders et al, 2015Wanders et al, , 2017 and this threshold was calculated separately for the natural situation and for the human-affected simulation shown in the right panels. All thresholds are standardized by the annual mean threshold of the natural situation.…”

Assessment of Climate Change Impact on Reservoir Inflows Using Multi Climate-Models under RCPs—The Case of Mangla Dam in Pakistan

“…Various authors used SRES scenarios for climate change impact studies [11][12][13][14][15], nowadays those scenarios have become outdated. Most of the research to date in the Jhelum and Upper Indus Basin Mean monthly temperature and precipitation in Mangla watershed and sub-basins are specified in Figure 2.…”

Achieving Water and Food Security in 2050: Outlook, Policies, and Investments

“…Improvements in the representation of groundwater systems in river basin models that normally highlight surface water, will enhance understanding of climate change impacts, given the importance of groundwater system characteristics in determining the number and duration of droughts [76][77][78].…”