Accurate forecasts of water flow provide fundamental information for hydropower companies and water management authorities in order to optimize operations and improve efficiency.
In remote locations with large inflow reservoirs of difficult access and challenging forecasting points, current solutions are limited by the scarce amount of in-situ data, complex operational systems, extreme topographic conditions, and lack of communications systems.
The main objective of the hydroflow forecast system is to improve reservoir management with reliable information, preventing losses associated to climatic variability, and to make them available on a clear web-based decision support system.
Hydroflow includes the measurement of in-situ temperature, precipitation, solar radiation, water level, soil moisture. Reservoir water level is estimated using a novel technology based on the measurements of Global Navigation Satellite System (such a s GPS and Galileo) signals reflected by the lake surface (GNSS-R). If required, in situ information can be sent by satellite communications, in order to provide real-time data to the model. Interfacing and integration of in situ data provided by the client or external institution is also included.
Space based Earth Observations of temperature maps and snow cover are used operationally by the system. Snow cover and temperature maps can be measured by optical instruments, with the limitation of cloud cover that occurs regularly during the melting season, and coarse resolution not suitable for hydrological modelling. Whereas temperature can be completed by in situ measurement, extrapolated and downscaled using a digital elevation model, snow cover is more difficult to downscale and extrapolate. For this reason the proposed service includes the acquisition of SAR images which are cloud immune and have a resolution suitable for the hydrological model. Using state of the art algorithms, optical and SAR images can be fused in order to produce high resolution realistic maps of the snow cover.
A distributed hydrological model is initialised with digital elevation data, land use and soil type maps, and calibrated using historical meteorological and flow data. It is then capable of producing short term (days) to long term (seasons) water flow forecasts at points of interest by taking as starting points an updated state of the basin (from updated geophysical information) and meteorological forecasts.
All the information (from in situ instruments, satellite observations, historical data, and model output) is centralized on a secure server running a database as well as services required for data flow and automation. Routines on this server will produce water flow reports, including quality indicators, as well as system health indicators available by the service team.
The output of the service is a complete forecast of the water-flow based on near real time physical observations delivered automatically to the user on a weekly basis. This forecast is computed at points of interest of the basin, that match input variables in the operational model, and therefore usable directly in their management practices.
The Hydroflow system has been developped in partnership with the European Space Agency and ENDESA CHile in the frame of the Artes20 IAP project INTOGENER.