Remotely Sensed Cotton Evapotranspiration for Irrigation Water Management in Vulnerable Agriculture of Central Greece

Abstract

Water for food production represents by far the largest share among all uses and its demand keeps growing with increasing population. The lack of water can affect disfavour the economic and social stability of entire regions. New technologies (Earth Observation, Geographic Information Systems) provide the possibility of time and spatial observation for the decision support and management. In this paper applied principles of precision agriculture through variable-rate inputs by the efficient monitoring of crop needs in space and time, defined zones of sustainable production by means of parallelepiped supervised classification using two indices, the soil maps and the DEM and described the process for the computation of crop evapotraspiration ETp for cotton fields in central Creece, a high agricultural productivity area that produces high quality products. The methodology was also used in Project PLEIADeS and new projects SMART and HYDROSENSE. For the data collection cotton fields were used. NOAA/AVHRR images consist the data base for the estimation of Water Limited Growth Environment (WLGE) and Landsat TM satellite images were processed for the extraction of reflectance, NDVI, RGB, ETp, Fractional cover, Kc maps. The objectives of this paper target to calculation of water balance with the use of satellite data and GIS, efficient use of water in water limited environments, improvement of irrigation systems with the use of new technologies, contribution to rational management of water resources in agriculture. Methodology can be applied in large scale areas and extend to other crops using satellite data. The results are in good agreement with ground- truth observations.