Dry-wet asymmetricity in changes of future surface water flow: an
event-wise analysis
Abstract
Many researchers have studied the terrestrial water cycle at global and
local scales, determining the reasons for its change over time, space,
and changing climates. However, event-wise analysis in a higher
frequency variability (e.g., daily scale) of surface water flow and the
associated complexity in its change remains unexplored. We define
magnitude and duration for wet and dry phases of CaMa-Flood simulated
discharge (forced by 10 CMIP6 model runoffs) for two future scenarios
(SSP126 and SSP585) and compare them with their respective historical
scenario to unravel the intricacies accompanied by shifts in discharge
under climate change. We found a substantial wet-dry asymmetricity in
magnitude and duration shifts, particularly for extreme events. Further,
these asymmetric shifts are more prominent for the dry phase than the
wet phase for the duration of events, whereas magnitude shifts in the
wet phase are more pronounced than the dry phase. There is an
intensification of magnitude and duration of moderate events for both
dry and wet phases, while for extreme events increase in wet phase
magnitude and duration is complemented by a decrease in dry phase
changes. Additionally, the discharge shifts are associated with
relatively homogenous magnitude-duration shifts for the dry phase than
the wet phase, particularly for extreme events. Our research reveals a
rather voluminous wet-phase shift than dry-phase shifts but lengthier
dry-phase shifts than wet-phase shifts for warmer climates in the future
that tend to intensify with additional warming for most regions of the
world.