Evaluating a reservoir parametrization in the vector-based global routing model mizuRoute (v2.0.1) for Earth system model coupling

Abstract. Human-controlled reservoirs have a large influence on the global water cycle. While hydrological models use generic parameterizations to model dam operations, representation of reservoir regulation is still lacking in many Earth system models. Here we implement and evaluate widely used parametrization river-routing mizuRoute, which operates vector-based river network resolving individual lakes currently being coupled an model. We develop approach determine downstream area over aggregate irrigation demand per reservoir. The implementation managed evaluated by comparing them simulations ignoring inland waters with represented as natural using (i) local for 26 driven observed inflows (ii) global-domain runoff from Community Land Model. show clear added value parametrization, especially simulating storage multi-year capacity. In application, shows improvement outflow compared no-reservoir simulation, but similar performance found lake parametrization. limited impact skill statistics could be attributed biases simulated discharge, mainly originating Finally, comparison modelled monthly streamflow indices against observations highlights that including operations improves simulation reservoirs. This study overall underlines need further test management order improve anthropogenic interference terrestrial cycle