Detection and counting of meadow cuts by copernicus sentinel-2 imagery in the framework of the common agricultural policy (CAP)

ABSTRACT

Greening is a subsidy provided by the Common Agricultural Policy (CAP), related to mowing and designed to protect environment. National or regional paying agencies (PP) monitor and verify compliance of farmers’ declarations with CAP rules. In this work, an operational procedure is proposed aimed at supporting PPs in detecting, mapping and quantifying the number of times mowing occurred in a meadow field. In particular, 72,539 meadows fields within the Piemonte region (NW – Italy) were analysed with a time series of Sentinel-2 (S2) data. The procedure is based on the processing of filtered and regularized time series of NDVI maps. The Fast Fourier Transform (FFT) was applied at field level to decompose the local NDVI temporal profile. The frequency (${\omega }_{peak})$ corresponding to the maximum amplitude ($A_{peak})$ was therefore considered. $A_{peak}$ value was used to detect not-mowed meadows by thresholding based on the application of the non-parametric Kolmogorov-Smirnov test. Mowing counting were achieved with reference to ${\omega }_{peak}$ and the correspondent map (called MCM) generated for the study area. MCM was, finally, tested against the validation set (285 fields). Results showed an Overall Accuracy (OA) > 87%, confirming the effectiveness of the proposed procedure in detecting, mapping and quantifying the number of times mowing occurred.

KEYWORDS:

• Meadow cuts
• CAP controls support
• NDVI time series
• frequency analysis
• agriculture monitoring
• S2 data

Acknowledgments

We would like to thank Elena Xausa and Gianluca Cantamessa, technicians for the Piemonte Regional Agency for Payments in Agriculture (ARPEA) for providing guidelines and fundamental operational information useful for reaching the results presented in this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This research was funded by the Piemonte Regional Agency for Payments in Agriculture within the research contract titled Gestione e sperimentazione del monitoraggio satellitare come metodologia alternativa ai controlli oggettivi di ammissibilità superficiCIG: [ZDF2F1BE82].