Winter Wheat Extent Maps (2001–2020) for the Bulgaria–Turkey Cross-Border Region Using the Peak Value Method (PVM)

This dataset supports the research presented in the Ph.D. dissertation by Aparna R. Phalke, titled "Investigating the Impacts of Support Policies on Agricultural Land Use and Production with Satellite Remote Sensing: A Case Study in the Cross-Border Area Between Turkey and Bulgaria" (University of Wisconsin–Madison, 2021). The dataset represents one of the core outputs of the dissertation and provides the first consistent, field-scale annual maps of winter wheat extent (2001–2020) across Bulgaria and northwestern Turkey using the Peak Value Method (PVM), a novel, training-independent remote sensing approach. These maps contribute to understanding long-term agricultural dynamics in support of cross-border monitoring and policy evaluation. Table A1: Final threshold combinations (MaxDOY and MaxEVI) for winter wheat area mapping in the study area for data available years, showing corresponding model performance metrics (R² and RMSE). Table A2: Annual winter wheat area (hectares) from 2001 to 2020 across all regions (NUTS1), provinces (NUTS2), and districts/municipalities (NUTS3) in Bulgaria and northwestern Türkiye. The table presents field-scale estimates generated using the Peak Value Method (PVM), capturing spatiotemporal variation in wheat extent at sub-national administrative levels. Data are organized by country, planning region, province, and district. Table A3: Time-series cultivated area (hectares) from 1995 to 2018 across all regions (NUTS1), provinces (NUTS2), and districts/municipalities (NUTS3) in Bulgaria and northwestern Türkiye. The dataset includes GeoTIFF files with 20 bands, each representing annual winter wheat area for the years 2001–2020. In each band, wheat areas are coded as 1 and non-wheat areas as 0. All preprocessing, EVI extraction, threshold optimization, and accuracy assessment workflows are documented and reproducible via the accompanying GitHub repository. Code and documentation: https://github.com/aparnaphalke/PeakValueMethod_WinterWheatMapping Please cite this dataset as:Phalke, A.R. (2025). Annual Winter Wheat Maps for Bulgaria–Turkey (2001–2020). Zenodo. https://doi.org/xxxxx (Replace with actual DOI after submission) For now: 10.5281/zenodo.15612010 Phalke, A.R., 2021. Investigating the Impacts of Support Policies on Agricultural Land Use and Production with Satellite Remote Sensing: A Case Study in the Cross-Border Area Between Turkey and Bulgaria. University of Wisconsin–Madison.