River discharge estimation at virtual stations by using in situ records or drone measurements of bathymetry, flow velocity and water level
River discharge, the volumetric rate of water flow passing a cross-section of a river, plays a crucial role in various aspects such as water supply planning and management, reservoir management and operation, hydropower generation, predicting and controlling floods, comprehending the global water cycle, and other hydrological applications. It has always been crucial to evaluate river discharge accurately and consistently for a variety of reasons, such as managing water resources, preventing flooding, and other hydrological applications. Traditionally, river discharge measurements are directly accomplished based on the velocity-area method that relies on measures of streamwise depth-averaged velocity. Following the discharge's acquisition, a calibrated rating curve can be developed by relating it to the associated stage. As a result, rating curves provide an ongoing and automated assessment of river discharge through the monitoring of water levels.
The traditional techniques of flow characteristics measurements are relatively costly, time-consuming, and dangerous for operators, especially during flood conditions and further, they are not feasible in remote and inaccessible sections. Further, discharge measurements need to be continuous and the used methods should be simple, sufficient, and cost-effective. Therefore, to overcome these challenges remote sensing procedures would be of particular importance to estimate river discharge. In this direction, researchers have extensively utilized remote sensing data, including satellite information, drone measurements, and UAS techniques to measure the flow of rivers (Bjerklie et al., 2003; Paris et al., 2016; Mansanarez et al., 2019; Bandini et al., 2020).
The project aims to develop a procedure to estimate river discharge from the satellite altimetry observations. In order to be able to estimate river discharge also in ungauged sections or remote areas, the use of drone for the measurements of bathymetry, surface flow velocity and water level is also addressed at the satellite tracks. In order to streamline the calculation of river discharge and achieve greater accuracy in the results, the cross-sectional velocity and consequently the river discharge can be estimated based on the application of theoretical methods, e.g. the entropy theoretical concept (Bahmanpouri et al. 2022a, Bahmanpouri et al. 2022b) to predict the cross-sectional velocity distribution and river discharge magnitude relying on water surface velocity.