A Real Time Forecasting System for Irrigation Management

In recent years frequent periods of water scarcity have enhanced the need to use water more carefully, even in European areas traditionally rich of water such as the Po Valley in Northern Italy. In dry periods, problems of water shortage can be enhanced due to the conflictual uses of water by irrigation, industry and power production (both hydroelectric and thermoelectric plants). Further, over the last decade, the social perspective about this issue is increasing due to possible impacts of climate change and global warming scenarios. The possible future increasing of frequency of drought periods stimulates the improvement of irrigation and water management. In this study we show the development and implementation of a real-time drought forecasting system, named PRE.G.I., an Italian acronym that stands for “Hydro-Meteorological forecast for irrigation management”. This system is based on an ensemble forecasts in a 30-days range with hydrological simulations of water balance to forecast the soil moisture at field scale. The studied area is in the middle of the Po Valley, but the local behavior depends on the processes in the nearby alpine area. The atmospheric-hydrological ensemble forecasts are based on 20 meteorological members of the non-hydrostatic WRF-ARW model coupled with an the rainfall-runoff distributed FEST-WB model, a hydrological model used to generate the soil moisture predictions. The hydrological model was validated against measurements of latent heat flux acquired by an eddy-covariance station, and soil moisture measured by TDR probes. Reliability of the forecasting system and its benefits were assessed on the growing season of 2012. Obtained results show how the proposed drought forecasting system is able to give a reliable forecast at least for a couple of weeks ahead.