Multiple human pressures and their spatial patterns in European running waters

Area of Science:

• Environmental Science
• Ecology
• Riverine Ecosystems

Background:

• European running water ecosystems are subject to numerous human-induced stressors.
• Understanding the prevalence, spatial distribution, and interactions of these pressures is crucial but limited.
• Previous research has not provided a high-resolution, pan-European analysis of multiple anthropogenic impacts.

Purpose of the Study:

• To conduct the first high-resolution data analysis of human pressures across European river systems.
• To identify and quantify major anthropogenic degradation criteria affecting rivers.
• To assess the prevalence, spatial patterns, and co-occurrence of multiple pressures on river ecosystems.

Main Methods:

• Analysis of 15 key pressure criteria at 9330 sampling sites across 14 European countries.
• Development of a global pressure index accounting for the additive effects of multiple stressors.
• Assessment of impacts on water quality, hydrology, morphology, and connectivity at different spatial scales.

Main Results:

• Rivers are significantly impacted by water quality alterations (59%), hydrological changes (41%), and morphological degradation (38%).
• River connectivity is disrupted at the catchment level (85%) and river segment level (35%).
• Only 21% of sites are unaffected; 47% are multi-impacted, with 90% of lowland rivers affected by all four pressure groups.

Conclusions:

• Human pressures are pervasive and often cumulative in European river ecosystems.
• Multi-impacted sites are common, especially in lowland areas, highlighting the need for integrated management strategies.
• The study provides a comprehensive baseline for understanding and mitigating anthropogenic impacts on European rivers.