River Condition Assessments (MoRPh)
Photo Credit: Linda Pitkin/2020VISION
River Condition Assessments (MoRPh)
MoRPh (Modular River Physical) assessments are used to evaluate rivers and streams by recording key physical and environmental characteristics. These include sediment type, physical habitats, vegetation structure, as well as human pressures and interventions.
The method and tool is designed to monitor the detailed form and function of river systems, and to track how they change over time in response to natural processes or human activities.
Surveys should be carried out during periods of low flow to ensure good visibility and accurate data collection.
All collected data is uploaded to the MoRPh database, where it can be mapped, graphed, and downloaded for further analysis.
When is it used?
MoRPh surveys are used in situations where there is a need to understand, monitor, or assess changes in a river’s physical condition. This includes:
- On Biodiversity Net Gain (BNG) sites where land use is changing within 10 m of the bank edge
- To track how a river responds to natural processes, including baseline and post-intervention surveys
- To assess the impact of interventions, such as restoration or engineering works
- To investigate impacts, for example where there are concerns about pollution or physical modification
Key Components of MoRPh Surveying:
River Type
- A desk-based study identifying the river type for the length being assessed.
- The river type translates the preliminary condition score for each MoRPh5 into a final river condition class, which reflects the site survey and wider contextual information.
Field Survey
- A field survey characterises the local physical structure of a river channel and margins.
- MoRPh5 - A sequence of 5 contiguous field surveys (50-250m) that draws upon the recorded field data to calculate indicators that contribute to a condition score.