Estimation of river discharge based on remote sensing of a river plume

Abstract

Satellite remote sensing is an efficient tool to identify buoyant river plumes in the coastal ocean, formed by interaction between the river and the ambient sea waters. The observed spatial extent, shape and orientation of the plume are indicative of the respective river discharge. A new method of reconstructing the volume of river discharge using satellite imagery and numerical modelling is presented in this article. At the first step of the procedure, we use a high resolution satellite image of the coastal area adjacent to the examined river estuary to identify the buoyant plume. Then a number of required river, atmospheric and sea parameters (including river discharge) are prescribed for the hydrological model to simulate the spread of river discharge under this configuration. The characteristics of the simulated river plume are compared with the corresponding characteristics of the plume identified at the satellite image. Varying model forcing conditions and iteratively improving the accordance between these plumes we consequently specify the value of river discharge. The developed method was applied for the eastern coast of the Black Sea to evaluate the influence of the short-term and annual precipitation conditions on the variability of river discharge inflowing from the Russian coast to the Black Sea.