River risk assessment based on ecosystem level

The current methods of ecological risk assessment(ERA) are difficult to be applied on ecosystem level,since they mainly focus on specific materials or species.An ecosystem-based river ERA method was developed depending on the concepts of system ecology and complex system theory.Distinguishingly,the method selected Ecosystem Services as assessment endpoints,and quantified Pressure-Response relationship between external stress on ecosystem and Ecosystem Services.Yellow River in China was chose as a case study.The results suggest that the most risky area of Yellow River ecosystem were middle and lower reaches;the main risk sources were urban and agriculture;and the most dangerous targets were habitats and biota.By its application in Yellow River,this method was showed to strongly support ecosystem-based river management.