Enhancing river health assessment: Innovations and applications of the AquaShan Index

[Display omitted] •Developed the AquaShan Index, an advanced method for river health assessment combining biological and environmental data.•Applied Random Forest analysis for precise weighting of environmental variables in river ecosystem evaluation.•Analyzed extensive data from South Korea's river ecosystems, focusing on benthic macroinvertebrates and environmental factors.•Demonstrated greater accuracy of the AquaShan Index in identifying river health issues compared to traditional indices.•Provided a practical, adaptable tool for informed river management and conservation decision-making. This study introduces the AquaShan Index, an innovative approach to assessing river health, which integrates biological indicators with key environmental variables. This index represents an advancement over traditional methods, like the Shannon Diversity Index, by including both species diversity and environmental factors such as dissolved oxygen, pH, and water temperature. Utilizing data from the Stream/River Ecosystem Survey and Health Assessment in South Korea, covering 5,952 data over three years, the study combines species data of benthic macroinvertebrates with environmental parameters, applying Random Forest analysis to weight these variables. The AquaShan Index formula incorporates species’ pollution tolerance scores, offering a nuanced perspective on ecosystem resilience to environmental stressors. Our results show a wide range of river health conditions, with the AquaShan Index demonstrating greater sensitivity and specificity in identifying ecological impairments compared to traditional indices. The inclusion of pollution tolerance scores and environmental variables provides a more comprehensive assessment of river health, revealing a higher number of sites with ecological challenges than previously identified. The AquaShan Index's adaptability and comprehensive approach make it a valuable tool for informed decision-making in river conservation and management, offering an enhanced methodology for assessing and sustaining river ecosystem health.