Surface runoff (R), which is another expression for river water discharge of a river basin, is a critical measurement for regional water cycles. Over the past two decades, river water discharge has been widely investigated, which is based on remotely sensed hydraulic and hydrological variables as well as indices. This study aims to demonstrate the potential of upstream global positioning system (GPS) vertical displacement (VD) and its standardization to statistically derive R time series, which has not been reported in recent literature. The correlation between the in situ R at estuaries and averaged GPS-VD and its standardization in the river basin upstream on a monthly temporal scale of the Mekong River Basin (MRB) is examined. It was found that the reconstructed R time series from the latter agrees with and yields a similar performance to that from the terrestrial water storage based on gravimetric satellite (i.e., Gravity Recovery and Climate Experiment (GRACE)) and traditional remote sensing data. The reconstructed R time series from the standardized GPS-VD was found to have a 2-7% accuracy increase against those without standardization. On the other hand, it is comparable to data that are obtained by the Palmer drought severity index (PDSI). Similar accuracies are exhibited by the estimated R when externally validated through another station location with in situ time series. The comparison of the estimated R at the entrance of river delta against that at the estuaries indicates a 1-3% relative error induced by the residual ocean tidal effect at the estuary. The reconstructed R from the standardized GPS-VD yields the lowest total relative error of less than 9% when accounting for the main upstream area of the MRB. The remaining errors may be the result of the combined effect of the proposed methodology, remaining environmental signals in the data time series, and potential time lag (less than a month) between the upstream MRB and estuary.environments. There is no global coverage of gauging network, however, that monitors the RWDs [7]. Apart from this, the frequency of discharge data acquisition has continuously declined since the late 1970s [8] because of insufficient funds for facility maintenance and upgrade [9]. As a result, indirect methods for the RWD monitoring, such as remote sensing (RS), have recently gained increasing interest.Traditional RS, such as Landsat Thematic Mapper (TM) and its Enhanced TM Plus (ETM+) images, as well as moderate resolution imaging spectrometer (MODIS), have passively recorded instantaneous surface parameters since the 1990s (e.g., [7]). The surface parameters obtained from RS [10][11][12][13], such as flood area inundation, land surface temperature (LST), normalized difference vegetation index (NDVI), and RS-derived geometric variables (e.g., river width), allow the direct correlation with water level or RWD. Except for the RS-derived geometric variables, the foregoing localized RS data yield indirect relationships to the RWD. Although RS-derived geometric variables can a...