Representation and improved parameterization of reservoir operation in hydrological and land-surface models

Abstract

Reservoirs significantly affect flow regimes in watershed systems by changing the magnitude and timing of streamflows. Failure to represent these effects limits the performance of hydrological and land-surface models (H-LSMs) in the many highly regulated basins across the globe and limits the applicability of such models to investigate the futures of watershed systems through scenario analysis (e.g., scenarios of climate, land use, or reservoir regulation changes). An adequate representation of reservoirs and their operation in an H-LSM is therefore essential for a realistic representation of the downstream flow regime. In this paper, we present a general parametric reservoir operation model based on piecewise-linear relationships between reservoir storage, inflow, and release to approximate actual reservoir operations. For the identification of the model parameters, we propose two strategies: (a) a "generalized" parameterization that requires a relatively limited amount of data and (b) direct calibration via multi-objective optimization when more data on historical storage and release are available. We use data from 37 reservoir case studies located in several regions across the globe for developing and testing the model. We further build this reservoir operation model into the MESH (Modélisation Environmentale-Surface et Hydrologie) modeling system, which is a large-scale H-LSM. Our results across the case studies show that the proposed reservoir model with both parameter-identification strategies leads to improved simulation accuracy compared with the other widely used approaches for reservoir operation simulation. We further show the significance of enabling MESH with this reservoir model and discuss the interdependent ef-fects of the simulation accuracy of natural processes and that of reservoir operations on the overall model performance. The reservoir operation model is generic and can be integrated into any H-LSM.

On the representation of water reservoir storage and operations in large-scale hydrological models: implications on model parameterization and climate change impact assessments

“…Climate forcings are represented by precipitation and air temperature (maximum and minimum), which must be provided at a daily time step. As far as precipitation is concerned, we use the APHRODITE dataset (Asian Precipitation -Highly-Resolved Observational Data Integration Towards Evaluation), developed by the University of Tsukuba, Japan, using rain-gauge data (Yatagai et al, 2012). APHRODITE is available with a spatial resolution of 0.25 • and has been shown by Lauri et al (2014) to be the most suitable precipitation dataset available for the Mekong basin.…”

Inferred inflow forecast horizons guiding reservoir release decisions across the United States

“…To provide these essential services, dams must be operated efficiently for uncertain hydrological conditions days and weeks ahead. Water managers thus rely increasingly on reservoir inflow forecasts to guide water release decisions (Gong et al, 2010;Boucher and Ramos, 2018) and will continue to do so as the range, resolution, and quality of hydrological forecast products continue to advance (e.g., Wang and Robertson, 2011;Yuan et al, 2015;Bennett et al, 2016). Inflow forecasts are valuable because they help operators manage difficult trade-offs.…”

Coordination and Control: Limits in Standard Representations of Multi-Reservoir Operations in Hydrological Modeling

“…Despite its relative simplicity, the release rule proposed here shares several important characteristics with other rules proposed in the literature. The logarithmic and exponential portions mirror the intuition that the release behavior is qualitatively different depending on storage levels, a trait emphasized by some recent release rules (Wu and Chen, 2012;Zhao et al, 2016;Wang et al, 2019;Yassin et al, 2019). Besides, the representation of reservoirs based on their primary purpose has been a recurring theme since the seminal release rules by Hanasaki et al (2006) and Haddeland et al (2006); the time-varying irrF req parameter also enables irrigation reservoir to have a flood control behavior in winter, similar to the improvement proposed by Voisin et al (2013a).…”