AUTHOREA
Log in
Sign Up
Browse Preprints
LOG IN
SIGN UP
Essential Site Maintenance
: Authorea-powered sites will be updated circa 15:00-17:00 Eastern on Tuesday 5 November.
There should be no interruption to normal services, but please contact us at
[email protected]
in case you face any issues.
Peter Greve
Public Documents
1
Most River Basins will Follow their Budyko Curves under Global Warming
Fernando Jaramillo
and 4 more
December 19, 2021
The Budyko framework consists of a curvilinear relationship between the evaporative ratio (i.e., actual evaporation over precipitation) and the aridity index (potential evaporation over precipitation) and defines evaporation’s water and energy limits. A basin’s movement within the Budyko space illustrates its hydroclimatic change and can help identify the main drivers of change. Basins are expected to move along their Budyko curves when only long-term changes in the aridity index drive changes in the evaporative ratio. We hypothesize that the increasing effects of global warming on the hydrological cycle will cause basins to move along their Budyko curves. To test our hypothesis, we quantify the movement in Budyko space of 353 river basins from 1901 to 2100 based on the outputs of nine models from the Coupled Model Intercomparison Project - Phase 5 (CMIP5). We find that significant increases in potential evaporation due to global warming will lead to basins moving primarily horizontally in Budyko space accompanied by minor changes in the evaporative ratio. However, 37% of the basins will still deviate from their Budyko curve trajectories, with less evaporation than expected by the framework. We elaborate on how land-use change, vegetation changes, or shifts in precipitation or snow to rain ratios can explain these deviations.