The relationship between catchment rainfall, evapotranspiration and runoff can be exploited
to assess climate risk to water resources. National data regarding climatology and runoff
were used to estimate the sensitivity of regional runoff to projected changes in precipitation
and evaporation. These sensitivity factors were integrated with patterns of climate change
from 12 different global climate model (GCM) simulations to project future annual runoff
sensitivity per degree of global mean temperature change. Divergent runoff sensitivities were
identified depending upon the selected GCM. Averaging among GCMs resulted in a robust
pattern of runoff sensitivity suitable for estimating future climate risk