Abstract
Climate change and drought phenomena impacts have become a growing concern
for water resources engineers and policy makers, mainly in arid and semi-arid areas. This study
aims to contribute to the development of a decision support tool to prepare water resources
managers and planners for climate change adaptation. The Hydrologiska Byråns
Vattenbalansavdelning (The Water Balance Department of the Hydrological Bureau) hydrologic
model was used to define the boundary conditions for the reservoir capacity yield model
comprising daily reservoir inflow from a representative example watershed with the size of
14,924 km2 into a reservoir with the capacity of 6.80 Gm3. The reservoir capacity yield model
was used to simulate variability in climate change-induced differences in reservoir capacity
needs and performance (operational probability of failure, resilience, and vulnerability). Owing
to the future precipitation reduction and potential evapotranspiration increase during the worst
case scenario (−40% precipitation and +30% potential evapotranspiration), substantial reductions
in streamflow of between −56% and −58% are anticipated for the dry and wet seasons,
respectively. Furthermore, model simulations recommend that as a result of future climatic
conditions, the reservoir operational probability of failure would generally increase due to
declined reservoir inflow. The study developed preparedness plans to combat the consequences
of climate change and drought.