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# How do geological map details influence the identification of geology–streamflow relationships in large-sample hydrology studies?

## Details

**Authors** Thiago V. M. do Nascimento, Julia Rudlang, Sebastian Gnann, Jan Seibert, Markus Hrachowitz, Fabrizio Fenicia

**Year** 2025

**Publisher** Hydrology and Earth System Sciences

**Kind of work** article

**Discipline** Hydrology

**Secondary disciplines** Geology

**Applied** false

[Read it at the publisher](https://doi.org/10.5194/hess-29-7173-2025) 
10.5194/hess-29-7173-2025

## In authors' words

### Abstract

Large-sample hydrology datasets have advanced hydrological research, yet the impact of landscape map details on identifying dominant streamflow generation processes remains underexplored. This study investigates the role of geology using maps of increasing detail, global, continental, and regional, each reclassified into four permeability classes. These geological attributes were used along with topography, soil, land use, and climate attributes to identify dominant controls on streamflow signatures across 4469 European catchments. To distinguish landscape influences from the otherwise dominant influence of climate, separate analyses were conducted on nested basins at three scales: large (63 nested basins), intermediate (the Moselle nested basin), and small (five nested catchments within the Moselle). At the large scale, dominant controls varied widely between nested basins, but landscape generally outweighed climate. At this scale, continental and global geology maps produced different correlation patterns, with neither consistently superior. At the intermediate scale, increased geological detail led geology to shift from the least to the most correlated variable for certain streamflow signatures. The small-scale experiment reinforced these findings, as the regional map highlighted controls more consistent with process understanding. This study underscores the benefit of integrating detailed, region-specific geological data into large sample hydrology studies, and demonstrates the utility of a nested basins design.

### What they set out to do (purpose)

To determine whether the level of detail in geological maps, global, continental, or regional, changes which landscape and climate attributes are identified as dominant controls on streamflow behavior.

### Who or what was studied (sample)

4,469 European catchments, with focused nested-basin analyses at three scales: 63 nested basins, the Moselle nested basin, and five nested catchments within the Moselle.

### How they did it (methods)

Comparative correlation analysis of streamflow signatures against geology, reclassified into permeability classes from maps of three resolutions, alongside topography, soil, land use, and climate attributes, using a nested-basin design across large, intermediate, and small scales.

### What they found (results)

Increasing geological map detail changed which variable was identified as dominant: at the intermediate Moselle scale, geology shifted from the least to the most correlated variable for certain streamflow signatures as map resolution increased from global to regional, and finer-resolution regional maps produced correlation patterns more consistent with known hydrological process understanding than coarser global or continental maps.

## Commentary

### In short

The finding demonstrates the Systems pattern through its explicit nested part-whole basin design across three hierarchical scales, the Relationships pattern through the correlations measured between geological attributes and streamflow signatures, and the Perspectives pattern because the same catchments yield different identified dominant controls depending on the resolution of the geological map used.

**Patterns it shows** S, R, P

**Added** 2026-09-28

**How to cite this** Thiago V. M. do Nascimento, Julia Rudlang, Sebastian Gnann, Jan Seibert, Markus Hrachowitz, Fabrizio Fenicia (2025). How do geological map details influence the identification of geology–streamflow relationships in large-sample hydrology studies?. Hydrology and Earth System Sciences.