A framework for assessing river health in peri-urban landscapes

The definition and assessment of the health of river systems is a difficult and complex task. This is mainly because river systems are distributed over a large geographical space with unique biotic and abiotic characteristics attributed to a given catchment, the existence of competing perceptions of stakeholders and an inability to establish a clear rationale for a universal river health assessment methodology. Such complexity and uncertainty can be addressed through a river health assessment framework with step-by-step guidance to help river health management authorities develop site-specific tools suitable for their river systems by taking into account the local river ecohydrology, hydrobiology, water quality aspects and insights from river users. The present work proposes a river health assessment framework based on the key outcomes of a three year project and showcases the role of each step in the framework. The proposed framework consists of four steps: understand, identify, develop and apply. During the first step, a comprehensive understanding is obtained using historic and current water quality data. This information is supplemented with community understanding of the changing condition of river health. This knowledge is then used together with relevant multivariate stoical techniques to identify some key indicators for river health monitoring and assessment. Finally tools are developed to assess river health for community, environmental and management purposes. We developed two tools to assess the risk associated with river health for primary contact recreational activities and algal blooms using three key indicators.