IAHS-AISH Scientific Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

How do reservoirs affect local and regional floods and droughts? 

Manuela Irene Brunner
Manuela Irene Brunner
  • University of Freiburg, Earth and Environmental Sciences, Germany (manuela.brunner@hydrology.uni-freiburg.de)

Hydrological extremes can be particularly impactful in populated areas where they are modulated by human intervention such as reservoir regulation. However, little is known about how reservoir regulation affects hydrological extremes, particularly at a regional scale. Here, I present a large data set of natural and regulated catchment pairs in the United States and assess how reservoir regulation affects local and regional drought and flood characteristics. I show that (1) reservoir regulation affects drought and flood hazard at a local scale by reducing severity (i.e. intensity/magnitude and deficit/volume) but increasing duration; (2) regulation affects regional hazard by reducing spatial flood connectedness in winter and by increasing spatial drought connectedness in summer; (3) the local alleviation effect is only weakly affected by reservoir purpose for both droughts and floods. I conclude that both local and regional flood and drought characteristics are substantially modulated by reservoir regulation, an aspect that should neither be neglected in hazard nor climate impact assessments.

How to cite: Brunner, M. I.: How do reservoirs affect local and regional floods and droughts? , IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-5, https://doi.org/10.5194/iahs2022-5, 2022.