Anthropogenic activities accelerated the evolution of river trophic status

Abstract

Eutrophication has become one of the most serious problems facing water environments. Exploring the relationship between anthropogenic activities and river trophic status provides effective information for environmental improvement and restoration, whilst the relationship remains poorly understood. Herein, 5225 water samples were collected monthly from 12 tributaries covered upstream in the Three Gorges Reservoir, China during 2014–2020. Quantitative anthropogenic activities based on land-use covers were used to establish correlations with tributary trophic status in small-scale watershed. The results showed that tributary trophic status had significant spatio-temporal variations and was the highest in summer, especially in July and August. Quantitative anthropogenic activities can explain well the eutrophic frequency and eutrophication risk in tributaries. Furthermore, it was proved that anthropogenic activities could accelerate the evolution of trophic status. Our findings increased the understanding of the interrelationship between humans and the environment and can provide practical strategies for river environmental restoration.

Keywords

• Comprehensive trophic level index
• Eutrophication
• Human activity intensity
• Land-use cover change
• Three Gorges Project