Qiumei Ma, Xu Gui, Zheng Duan, Jiqing Li, Yuying Li, Lihua Xiong. Leveraging multi-source satellite imagery for improving daily reservoir water storage and inflow estimation in a catchment hydrological model. Journal of Hydrology，Available online 24 June 2025, 133761.  https://doi.org/10.1016/j.jhydrol.2025.133761

          Accurate reservoir dynamics, particularly water storage and inflow, are crucial for release decisions and operation impact assessments. However, the lack of sufficient monitoring data has hindered the accurate representation of reservoir behavior in hydrological models. While the increasing availability of satellite imagery provides unprecedented opportunities for dynamic reservoir monitoring, its potential to enhance hydrological models for simulating daily storage and inflow remains largely unexplored. This study aims to evaluate the applicability of optical (Landsat 8 and Sentinel-2) and Synthetic Aperture Radar (SAR, Sentinel-1) satellite imagery in extracting reservoir-specific Surface Water Extent (SWE), using these data as a calibration reference to constrain the Xinanjiang (XAJ) hydrological model for estimating daily reservoir water storage and inflow. To improve the accuracy of SWE identification, we use the random forest classification (RFC) for optical imagery and the OTSU algorithm for SAR imagery to distinguish water from non-water areas. Our study focuses on a large, multi-year regulated reservoir located in the upper reaches of the Wujiang River, namely the Hongjiadu Reservoir. The results show that: (1) SWE of the Hongjiadu Reservoir can be accurately extracted from satellite imagery using RFC and OTSU algorithms, particularly for Sentinel-1; (2) Using Sentinel-1-derived SWE as a calibration reference, the XAJ model performs excellently in simulating daily inflow, with a Nash-Sutcliffe Efficiency (NSE) of 0.92, and in reconstructing daily water storage volume with NSE of 0.98; and (3) A merged dataset of Sentinel-1, Sentinel-2, and Landsat 8 outperforms Sentinel-2 and Landsat 8 alone in reservoir area identification, water storage change estimation, and XAJ simulation, likely due to the greater availability and accuracy of Sentinel-1. These findings highlight the potential of satellite imagery in constraining hydrological models to simulate daily reservoir behaviors in highly regulated basins. This approach provides a crucial supplement or alternative to traditional gauge flow stations and opens new avenues for improving water resources management in data-scarce regions.

       《Journal of Hydrology》简介

       《Journal of Hydrology》是 NETHERLANDS 的 Amsterdam, New York, Elsevier, etc.于1963年出版的期刊。

        《Journal of Hydrology》是水文水资源领域历史最悠久、最有影响力的国际期刊之一。该期刊关注水资源研究领域的主要分支方向，包括物理、化学、生物地球化学、地表及地下水文地理学、水文气象学、水文地质学等。按美国科学情报研究所（ISI）的期刊引证报告（JCR），该期刊最新的影响因子为6.708，在中科院分区为一区Top期刊，在最新的分区表中位列水资源学科100种期刊中第6位。