A framework for integrated river health assessment: Application to the Weihe River Basin, China

Rivers provide essential ecosystem services and support socioeconomic development. This study proposes a comprehensive river health assessment framework for the Beiluo River, Weihe River, Heihe River in the Weihe River Basin, which functions as a key ecological barrier and major socio-economic corridor in northwestern China. The framework integrates five dimensions: hydrological, chemical, biological, and morphological integrity, as well as the sustainability of social services. Fourteen representative indicators were selected through a framework-based process to capture the core physical, chemical, biological, geomorphological, and functional attributes emphasized in widely accepted river health concepts. Five dimensions were weighted using the Analytic Hierarchy Process, with sustainability of social services receiving the highest weight, followed by hydrological and chemical integrity. The results indicated that the River Health Index (RHI) of the Beiluo River, Weihe River, Heihe River improved significantly from 2017 to 2023. RHI increased from 78.65 to 88.55 in the Beiluo River, from 72.10 to 89.00 in the Weihe River, and from 77.50 to 86.65 in the Heihe River. In 2023, the Beiluo River showed low biological integrity due to upstream mining and non-point source pollution, which degraded water and sediment quality and disrupted habitats. Impaired hydrological integrity and limited social services in the Weihe River, caused by excessive water extraction and low supply reliability. The Heihe River experiences altered flow regimes and degraded habitat conditions due to reservoir operations and tourism. River health assessment effectively reflects the overall condition of rivers and identifies deficiencies, providing a scientific basis for conservation and management.