Evaluation of river discharges derived from remote sensing and land surface models

This study assesses river discharges derived using remote sensing and hydrologic modeling approaches throughout the CONUS. The remote sensing methods rely on total water storage anomalies (TWSA) from the GRACE and GRACE-FO satellites and water surface elevations from altimetry satellites (i.e., JASON-2/3 and Sentinel-3) to estimate discharge. Surface and subsurface runoff from two Land Surface Models (LSM), NOAH and CLSM, are routed using the Hillslope River Routing model to determine discharge. The LSMs are part of NASA’s Global Land Data Assimilation System (GLDAS).本研究针对美国本土（Continental United States, CONUS）全域范围内，通过遥感与水文模拟方法推导得到的河道径流量开展评估。该遥感方法依托重力恢复与气候实验（GRACE）及GRACE后续任务（GRACE-FO）卫星获取的总水储量异常（Total Water Storage Anomalies, TWSA），以及测高卫星（即JASON-2/3与Sentinel-3）测得的水面高程来估算径流量。本研究采用坡面河道汇流模型（Hillslope River Routing model），对两款陆面模式（Land Surface Models, LSM）——NOAH与CLSM——输出的地表与地下径流进行汇流演算，以确定径流量。上述两款陆面模式均隶属于美国国家航空航天局（National Aeronautics and Space Administration, NASA）的全球陆面数据同化系统（Global Land Data Assimilation System, GLDAS）。