Mapping irrigated crops through Sentinel 2 satellite images: evidences from Southern Italy

The sustainability of irrigated water management is hampered by a lack of precise and timely information about irrigated crops and their applied water volumes. This is particularly crucial for arid and semi-arid regions of Mediterranean areas where water withdrawals (mostly from groundwater) are unknown, preventing water authorities from effectively planning and managing water use for agriculture. Remote sensing techniques have the potential to overcome such limitations allowing to monitor the crop biophysical parameters related with crop evapotranspiration and crop water use with suitable temporal and spatial resolution. In this study the performance of some Vegetation Indexes (VIs), to identify and mapping effectively irrigated areas in Southern Italy was investigated. VIs are extracted from Sentinel-2 images and relate to irrigated and non-irrigated olive groves in Apulian region being the leader Italian olive producer. Results show that VIs' distributions (rainfed vs. irrigated) are significantly different as confirmed by t-test and k-Smirnov test (p-value ranging between 0.0001 and 0.03). The space-time variability of irrigated crops map retrieved from remote sensed data could support water authorities in managing water resource abstractions and reduce costly monitoring practices such as in-situ inspections.