ABSTRACT
New hydrological datasets from earth observations, hydrological and land-surface models, as well as seasonal forecasts continue to be developed and tested around the world. Global precipitation datasets and global hydrological models are continuously being developed, tested and improved. A hydro-economic framework was developed and applied to evaluate the value of using longer periods of record as well as of ensembles of river discharge information from global precipitation datasets and global hydrological models in irrigated agriculture. The application of an ensemble of global hydrological models allows the use of shorter time periods in river discharge estimates compared to single global hydrological models. In corresponding subbasins, the application of a calibrated hydrological model is suitable to estimate the area to be cropped in irrigated agriculture. The hydrological models are under continuous process of improvement. If the decision maker would like to know about the available water for weekly water allocation announcements, a daily times scale would be necessary for an adequate evaluation.
