CVJul 7, 2025
Satellite-based Rabi rice paddy field mapping in India: a case study on Telangana statePrashanth Reddy Putta, Fabio Dell'Acqua
Accurate rice area monitoring is critical for food security and agricultural policy in smallholder farming regions, yet conventional remote sensing approaches struggle with the spatiotemporal heterogeneity characteristic of fragmented agricultural landscapes. This study developed a phenology-driven classification framework that systematically adapts to local agro-ecological variations across 32 districts in Telangana, India during the 2018-19 Rabi rice season. The research reveals significant spatiotemporal diversity, with phenological timing varying by up to 50 days between districts and field sizes ranging from 0.01 to 2.94 hectares. Our district-specific calibration approach achieved 93.3% overall accuracy, an 8.0 percentage point improvement over conventional regional clustering methods, with strong validation against official government statistics (R^2 = 0.981) demonstrating excellent agreement between remotely sensed and ground truth data. The framework successfully mapped 732,345 hectares by adapting to agro-climatic variations, with Northern districts requiring extended land preparation phases (up to 55 days) while Southern districts showed compressed cultivation cycles. Field size analysis revealed accuracy declining 6.8 percentage points from medium to tiny fields, providing insights for operational monitoring in fragmented landscapes. These findings demonstrate that remote sensing frameworks must embrace rather than simplify landscape complexity, advancing region-specific agricultural monitoring approaches that maintain scientific rigor while serving practical policy and food security applications.
CVJun 16, 2025
Joint Analysis of Optical and SAR Vegetation Indices for Vineyard Monitoring: Assessing Biomass Dynamics and Phenological Stages over Po Valley, ItalyAndrea Bergamaschi, Abhinav Verma, Avik Bhattacharya et al.
Multi-polarized Synthetic Aperture Radar (SAR) technology has gained increasing attention in agriculture, offering unique capabilities for monitoring vegetation dynamics thanks to its all-weather, day-and-night operation and high revisit frequency. This study presents, for the first time, a comprehensive analysis combining dual-polarimetric radar vegetation index (DpRVI) with optical indices to characterize vineyard crops. Vineyards exhibit distinct non-isotropic scattering behavior due to their pronounced row orientation, making them particularly challenging and interesting targets for remote sensing. The research further investigates the relationship between DpRVI and optical vegetation indices, demonstrating the complementary nature of their information. We demonstrate that DpRVI and optical indices provide complementary information, with low correlation suggesting that they capture distinct vineyard features. Key findings reveal a parabolic trend in DpRVI over the growing season, potentially linked to biomass dynamics estimated via the Winkler Index. Unlike optical indices reflecting vegetation greenness, DpRVI appears more directly related to biomass growth, aligning with specific phenological phases. Preliminary results also highlight the potential of DpRVI for distinguishing vineyards from other crops. This research aligns with the objectives of the PNRR-NODES project, which promotes nature-based solutions (NbS) for sustainable vineyard management. The application of DpRVI for monitoring vineyards is part of integrating remote sensing techniques into the broader field of strategies for climate-related change adaptation and risk reduction, emphasizing the role of innovative SAR-based monitoring in sustainable agriculture.