Mapping yearly irrigation patterns across Italy using multiple satellite data from 2000 to 2025

Climate change and population growth are putting increased pressure on water resources and their users in Italy and the Mediterranean (IPCC 2023). Italy is among the European countries that make the greatest use of irrigation (70% of total freshwater consumption), and about 60% of the area is irrigated with low-efficiency techniques (ISTAT 2014). Despite its significance, the yearly detection of irrigated fields remains poorly quantified at national scales with 1-km spatial resolution. A multi-sensor, satellite-driven framework was developed to map irrigated areas across Italy over the past years based on a change detection algorithm for the 8-day normalized difference vegetation index (NDVI) from MODIS, soil moisture from Sentinel-1, land surface temperature (LST) from MODIS, and precipitation from ERA5-Land. The datasets are harmonized and analyzed to produce statistical maps and temporal trends, providing a detailed characterization of irrigated areas. The retrievals are intercompared and validated against reference datasets from local field knowledge, the official national statistics data, and global research datasets. Inconsistency has been found in some areas, especially due to the difficulties in differentiating between rainfed and irrigated crop areas. No significant differences in the irrigated areas were observed between the different years.

This spatially continuous, multi-decadal assessment provides a methodology applicable to Mediterranean and semi-arid regions and delivers essential insights to support sustainable water management, agricultural planning, and climate adaptation strategies.