Nested Catchment Delineation at the European Scale: A Tool for Fine-Scale Environmental Analysis

The delineation of hydrological catchments and river networks is fundamental for hydrographic and hydrological information, environmental analysis, modeling, and decision-making. However, many existing datasets are limited in their spatial resolution, which can constrain their ability to accurately represent localized processes such as floodplain dynamics and soil erosion patterns. Building on the concepts of the new vector-based global river network dataset by Lin et al. (2021), Catchment Characterisation and Modelling (CCM) by the Joint Research Centre (JRC) (Vogt et al., 2003), as well as HydroSHEDS by the World Wildlife Fund US (Lehner and Grill, 2013), we aim to introduce a finer spatial scale that captures regional nuances and enhances hydrological detail. Using high-resolution digital elevation data, this study applies a hierarchical coding system to delineate nested catchments across Europe, achieving basin sizes reduced to a fine scale. The methodology ensures the accurate representation of catchments and associated river networks, with a focus on maintaining hydrological connectivity.

This delineation approach allows for the creation of a comprehensive geospatial dataset that integrates detailed catchment and river attributes. Our work complements existing large-scale datasets, providing critical insights for regional and local hydrological and environmental applications. The product/dataset will support environmental analysis by enabling the calculation of catchment-scale statistics for a wide range of environmental, soil, and land degradation parameters, including soil properties, soil erosion and land degradation, hydrological factors, ecological indicators, land use and land cover characteristics across Europe.

By generating a high-resolution, hierarchically nested dataset, this project addresses various environmental challenges at both regional and European scales, while meeting the increasing demand for spatially detailed environmental data that covers specific regional needs. The resulting data will support applications in land management, soil conservation, and environmental policy, providing a robust framework for both scientific research and practical implementation.

Acknowledgement: K.K, F.M., P.B, were funded by the European Union Horizon Europe Project Soil O-LIVE (Grant No. 101091255). P.S. was funded by the European Union Horizon Europe Project AI4SoilHealth (Grant No. 101086179).

References:

Lehner, B., & Grill, G. (2013). Global river hydrography and network routing: baseline data and new approaches to study the world's large river systems. Hydrological Processes, 27(15), 2171-2186.

Lin, P., Pan, M., Wood, E. F., Yamazaki, D., & Allen, G. H. (2021). A new vector-based global river network dataset accounting for variable drainage density. Scientific data, 8(1), 28.

Vogt, J., Colombo, R., Paracchini, M. L., de Jager, A., & Soille, P. (2003). CMM river and catchment database. Version, 1, 1-32.