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Volume XV |

Geomorphological mapping of steep new vineyard terraces: DJI Mavic 3M vs. Matrice T4 RTK performance with and without GCPs

Abstract: Soil erosion in steep vineyard terraces presents critical environmental challenges that require high-resolution, real-time geomorphological monitoring. Unmanned Aerial Vehicle (UAV) photogrammetry has revolutionized this field; however, an experimental gap persists regarding the operational need for Ground Control Points (GCPs) when utilizing high-precision Real-Time Kinematic (RTK) systems in extreme geometries. This study provides a rigorous comparative analysis between the DJI Mavic 3M and the DJI Matrice T4 (Thermal) platforms under two georeferencing configurations (RTK-only direct georeferencing vs. RTK+GCP workflows). Both drones were operated under identical parameters: flown on the same day at solar noon, with an 80% longitudinal and lateral image overlap, and at a flight altitude of 40 m above ground level. Four key topographic and soil erosion derivatives were extracted in ArcGIS Pro and statistically compared cell-by-cell using raster calculator algebra: Slope Gradient, Topographic Wetness Index (TWI), Convergence Index (CI), and the RUSLE LS-factor. The residual analysis revealed an outstanding structural alignment between workflows, with absolute median discrepancies restricted to 0.7° for slope, 0.4 for TWI, and 0.0 for CI. Absolute coordinate tracking across 10 independent checkpoints unveiled that the non-GCP workflow behaves as a perfectly rigid photogrammetric block, introducing an identical systematic translation vector (Delta X= 0.2 m, Delta Y= 5.4 m, Delta Z= -2.8 m) with near-zero standard deviations (approx. 0.1 m) for both platforms. Because neighborhood-cell algorithms remain unaffected by this rigid displacement, the derivative geomorphological maps are morphologically identical. These findings demonstrate that for high-resolution pedogeomorphological monitoring on steep slopes, the internal positioning stability of the DJI D-RTK 3 system successfully eliminates the operational dependency on physical ground control networks. This methodological shift significantly optimizes fieldwork efficiency, safety, and operational costs without compromising scientific rigor.

Volume XVII |

Playing with water – An introduction to experimental hydrology

Abstract: Water is the most important resource for the humankind, thus understanding hydrological processes could be con-sidered a vital task. Therefore, the main aims of this papers are to assess: (i) the current status of hydrologic field ex-periments; (ii) the techniques and the stages of the field hydrologic experiments at the microscale/plot-scale. Microscale hydrological studies are important both socially and economically as they emphasize the role of key factors (e.g. slope) in the utilization of water resources, the identification of critical hydrological thresholds for mobilizing, the propagation of soil particles in water flows and also the time it takes for pesticides, nutrients, and heavy metals to be mobilized. The key to conducting a successful hydrological microscale experiment lies in performing repeated attempts in the field. From an economic point of view, expedition (temporary) hydrologic field experiments are beneficial, as they shorten the working period and reduce the financial costs of the data acquisition process. One of the challenges of experimental hydrology is the manipulation of “upscaling” or the statistical approach taken towards gathering and processing data.