Remote sensing method for estimating green and blue water footprint

In this paper we propose an approach to decompose the water footprint (WF) using remote sensing data on a global scale. The WF of a crop is defined as the volume of water consumed for its production, where green and blue WE stand for rain and irrigation water usage, respectively. A method has been developed to separate WE into its green and blue components by analysing time series of earth observation data and model simulations on precipitation, soil moisture, evapotranspiration, runoff and water storage. The model takes into account the typical timescale of soil moisture depletion. Soil moisture estimates are retrieved from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), and the Global Land Data Assimilation System (GLDAS) are employed as a test dataset. The results show the identification of irrigation events and preliminary green and blue water calculations allowing us to assess the potential of the method.