Hydrological Model Calibration for Dammed Basins Using Satellite Altimetry Information
Ruida Zhong, Tongtiegang Zhao, Xiaohong Chen
Abstract
Abstract Downstream stakeholders are often hindered when performing water management decision making based on effective hydrological modeling and streamflow anticipation, due to alterations of river flow caused by upstream damming. Meanwhile, spaceborne altimeters and imagers can provide valuable data for the upper data‐limited reservoirs by monitoring their operations. This study proposes a novel modeling approach that incorporates reservoir levels from satellite altimetry into hydrological model calibration. Doing so enables model parameter determination and retrieval of upper reservoir inflow for dammed basins, when only the altered downstream flow observations are available. Case studies are performed for two large reservoirs in the Dongjiang basin, a typical dam‐affected area in South China. Two settings for determining the stage‐volume (S‐V) curve are tested: (1) The curves are prefitted by satellite information and (2) the curves are optimized by calibration in conjunction with the model parameters. Results show that the proposed approach is effective in identifying the hydrological model parameters and retrieving the upper reservoir inflow of data‐limited dammed basins. Our analyses also show that the error in satellite altimetry has significant influences and can impede reasonable determination of the model parameters, and the fitted S‐V curves perform more reasonably and robustly than calibrated S‐V curves with respect to retrieving reservoir inflow, and thus, the fitted S‐V curve is more highly recommended. Overall, our approach provides an effective solution for aiding downstream stakeholders and researchers in understanding the upper reservoir operation and analyzing the hydrology of dammed basins, when knowledge about the upstream area is limited.