Modelling losses of reservoir storage capacity from sedimentation in different landscapes

Reservoir sedimentation represents a significant threat to the reliability of global water and energy supplies. Over the life of a reservoir, storage capacity is gradually lost due to the deposition of sediments. Hydrological models represent a valuable method to study and evaluate the effects of reservoir storage losses on issues such as energy production, discharge capacity, and flood attenuation. The Hydrological Predictions for the Environment (HYPE) model is a semi-distributed, catchment-based hydrology model that has been used to quantify sediment fluxes across a variety of catchment, country, continent, and global modeling domains. In this study, several methods to estimate reservoir storage capacity losses due to sedimentation were added to HYPE, and their impact on sediment simulations and resulting model performance was tested in multiple landscapes in various parts of the world. Selected methods consider the texture and size of deposited sediment particles, the compaction of deposited sediments over time, and the manner in which reservoirs are operated. Results from the study will be used to inform future model development and improve modeling of sediment fluxes at the global scale.