Preliminary Analysis of PRISMA Imagery for Agricultural Drought Assessment in Italy

Over the past three years, agricultural drought has repeatedly affected Italy, resulting in unpredictable yield losses. This phenomenon is influenced not only by meteorological factors but also by vegetation phenology and soil moisture conditions, making effective monitoring essential to assess its severity and impacts.

Hyperspectral satellite imagery offers a promising tool for monitoring drought effects on vegetation due to its sensitivity to stress-related parameters. However, its effectiveness is often limited by the availability of reliable in situ data for validation.

This study utilized PRISMA, the Hyperspectral Precursor of the Application Mission of the Italian Space Agency (ASI), to analyze spectral signatures of drought-affected crop fields in comparison with in situ data provided by the Institute of Services for Agricultural and Food Market (ISMEA). PRISMA offers high spectral (240 bands, 400–2500 nm) and spatial (30 m) resolution. The in situ dataset includes standardized estimates of drought damage percentages (0–100%) at the field scale.

First, a terrain-independent correction approach was applied to address PRISMA’s geolocation error. Then, median spectral signatures were extracted for fields with varying damage levels, excluding bands affected by atmospheric absorption. One case study focused on durum wheat fields in Foggia (Southern Italy) during the 2022 season. Two cloud-free PRISMA images (29/04/2022 and 14/06/2022) were analyzed, revealing differences in the 700–1100 nm spectral range between fields with 0% and 36% damage. These bands are associated with leaf structure and water content, parameters influenced by drought stress.

Despite the limited dataset, the results demonstrate PRISMA’s potential for agricultural drought monitoring. Future efforts will expand the dataset to enhance analysis reliability.