A12. Modular River Survey (MoRPh, RCA)

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1. Objective

The MoRPh survey is designed to record the types and abundances of physical habitats (vegetation structure, sediment calibre, landforms, flow types) and human pressures and interventions that are present along short lengths of river at sufficient detail to support rigorous habitat assessments and to monitor subtle habitat changes.

2. Method summary

The MoRPh survey is available as a citizen science survey tool. It also forms a component of the River Condition Assessment (RCA) method that contributes to Natural England’s Biodiversity Metric (https://publications.naturalengland.org.uk/publication/6049804846366720).

Guidance on Health and Safety is provided during training courses and is presented in the MoRPh Technical Manual. Surveyors are required to adhere to their organisation’s detailed Health and Safety procedures when undertaking MoRPh surveys.

The MoRPh survey is undertaken from one or more locations on the river’s bank top. It captures detailed physical habitat information for 10 to 40 m lengths of stream or river (termed modules), where the module length depends upon the width of the river channel. The RCA methodology additionally allows 50 m survey lengths for canals, navigable rivers and large rivers (i.e. water courses where the channel width is too great and/or the water is too deep or cloudy for the river bed to be surveyed in detail).

The MoRPh survey ‘form’ can be completed on paper and subsequently uploaded to the Modular River Survey Information System, or can be completed via an ‘App’. The survey commences by locating the start and end points and the bank-top midpoint of the module to be surveyed. Three photographs are taken from the mid-point to capture the channel and bank immediately opposite the midpoint, the upstream and the downstream parts of the module. In some cases, it is not possible to take satisfactory photographs from the midpoint and so photographs can be taken from other locations to capture the nature of the module being surveyed. Up to six photographs can be uploaded to accompany each module survey, and photograph subjects and locations are recorded on the survey form to support survey data checking, approval and interpretation, and also as an aid to accurate re-location of modules when the survey is repeated for monitoring purposes.

The MoRPh form is comprised of four pages. The first page captures general information on the surveyor, survey date, survey location (including National Grid Reference or latitude-longitude of the mid-point), module length, channel dimensions, photograph locations and contents, and any other general comments regarding the survey.

The remaining three survey pages record information on the bank tops (within 10 m of the channel), the bank faces and the channel bed, respectively. The survey pages capture the entire area within each of these spatial units along the length of the surveyed module. Each sheet provides a check list of features that may be observed within the relevant area (bank top, bank face, bed). The features are grouped on each sheet according to vegetation morphology-structure, sediments, physical habitats-landforms, human interventions and pressures. The surveyor selects those features from each list that are observed within the module under consideration and records each feature’s abundance using an appropriate semi-quantitative scale. In this way, a comprehensive survey is assembled of the set of features that are present and their abundance within the entire module.

3. Advantages

  • Surveys are conducted at a scale that complements biological surveys, enabling linkages between organisms and physical habitats to be explored.
  • The variable survey length allows data-gathering at a spatial resolution appropriate to the size of stream or river surveyed
  • All observations within a MoRPh survey are collected for the same size of sampling unit (the module), with the features that are present and their abundance captured for that sampling unit. This provides a semi-quantitative single spatial-scale data set for analysis of module properties
  • MoRPh is ideal for monitoring and capturing changes at a site
  • Longer reaches can be surveyed at consistent detail by surveying contiguous (end-to-end) modules
  • MoRPh surveys can be conducted using an App and uploaded directly to the Modular River Survey Information System

4. Limitations

  • As for all habitat surveys, surveyor bias/error and subjectivity may affect some data but all surveys are checked for major errors prior to approval
  • The survey is appropriate for detailed local-scale survey but is too time-consuming for surveying long river lengths, where other habitat surveys would be more appropriate.

5. Recommendation for method application

  • Apply 1 to 3 end-to-end MoRPh module surveys for capturing detailed physical habitat data at and around biological monitoring sites
  • Apply 1 to 3 end-to-end MoRPh surveys for monitoring the impact of small individual interventions on the surrounding river environment (e.g. individual deflectors, leaky barriers etc.)
  • Apply MoRPh10 (for Citizen Science applications) or MoRPh5 (for RCA applications) to capture a detailed, integrated impression of physical habitat character beyond the local (single module) scale
  • Integrate MoRPh10 (for Citizen Science applications) or MoRPh5 (for RCA applications) into a BACI (Before-After-Control-Impact) design for investigating the impact of major interventions including restorations of rivers and streams.
  • Ensure accurate recording of survey mid-point positions (NGR or latitude-longitude) and accurate characterisation of the module, especially its mid-point, using photographs so that the module can be relocated accurately and changes can be visualised for monitoring purposes.
  • Undertake surveys in spring or autumn if possible
  • Survey at low flow to ensure bed visibility and thus reliable surveys.

6. Costs

Training courses are available for individuals or groups interested in either MoRPh or the RCA. Current charges can be found via the Modular River Survey website (https://modularriversurvey.org/). Training is required before surveyors are allocated a log-in to access the Modular River Survey Information System. RCA surveyors are certificated following attendance at the training course and delivery of a satisfactory assessment.

7. Data analysis

The Modular River Survey Information System is organised into workspaces (currently there are approximately 300 active workspaces). All trained surveyors are provided with a log-in to the relevant workspace(s) so that they can upload, download, query and map any of the survey data to which they have access. MoRPh surveyors have access to an open Citizen Science workspace and to approved surveys in other ‘open’ workspaces managed by various organisations. Currently the MoRPh Citizen Science database and related ‘open’ workspaces contain approximately 6000 surveys, mainly distributed across the United Kingdom and the Republic of Ireland. RCA surveyors have access to a private workspace that is only accessible within their organisation.

Raw survey data and photographs can all be downloaded for analysis from the workspaces. In addition, the Modular River Survey Information System generates a set of 14 summary indicators of the character and ‘quality’ of each surveyed module that can be mapped and downloaded for analysis. To generate data for specific applications, modules can be surveyed wherever they are needed and in the quantities needed to suit a range of applications. However, MoRPh and RCA methods offer specific options to generate additional insights beyond those associated with a single module survey.

MoRPh surveyors have the option of conducting a MoRPh10 survey, where the Information System extracts a set of 16 integrated indicators from 10 contiguous (end-to-end) MoRPh module surveys. These can be used to summarise the character of a 100 to 400 m long MoRPh10 subreach and to track changes through time from repeat surveys.

RCA surveyors conduct MoRPh5 surveys (5 end-to-end MoRPh modules), from which the Modular River Survey Information System extracts 32 Condition Indicator scores. 19 positive indicator scores quantify the diversity and abundance of a range of ‘natural’ properties of a 50 to 250 m long MoRPh5 subreach, whereas 13 negative indicator scores quantify the nature, severity and abundance of a range of human interventions and pressures. The 32 indicator scores give an overall impression of the condition of the subreach. They are combined to produce an integrated ‘Preliminary Condition Score’ for the subreach, which is then linked to the relevant hydromorphological River Type to assign a ‘Final Condition’ of Good, Fairly Good, Moderate, Fairly Poor or Poor to the subreach. Recently, an additional stage has been incorporated into the assessment whereby the Final Condition is reduced by one class if the channel is assessed to be overdeep and thus hydrologically disconnected as a legacy of human interventions.

8. Examples

MoRPh is currently being used:

9. More information

10. References

  1. Cox, E.J., Gurnell, A.M., Bowes, M.J., Bruen, M., Hogan, S.C., O’Sullivan, J.J., Kelly-Quinn, M.A. 2022. Multi-scale analysis and classification of the hydrogeomorphological characteristics of Irish headwater streams. Hydrobiologia. DOI: 10.1007/s10750-022-05013-5
  2. Gurnell, A.M., Downs, P.J. 2021. The legacy of river channel modification in wadeable, lowland rivers: exploring overdeep rivers in England. Earth Surface Processes and Landforms, 46, 3016–3025, DOI: 10.1002/esp.5268
  3. Gurnell, A.M., England, J., Shuker, L., Wharton, G., 2019. The contribution of volunteers to river monitoring: international and national perspectives and the example of the MoRPh survey. River Research and Applications, 35(8), 1359-1373, DOI: 10.1002/rra.3483
  4. Gurnell, A.M., England, J., Shuker, L., Wharton, G. 2019. The MoRPh Survey: Field Guide. Download from https://modularriversurvey.org/citizen-science-help/
  5. Gurnell, A.M., Scott, S.J., England, J., Gurnell, D.J., Jeffries, R., Shuker, L., Wharton, G. 2020. Assessing river condition: A multiscale approach designed for operational application in the context of biodiversity net gain. River Research and Applications, 36(8): 1559-1578, DOI: 10.1002/rra.3673.
  6. Gurnell, A.M., Shuker, L. 2022. The MoRPh Survey: Technical Reference Manual. Download from https://modularriversurvey.org/citizen-science-help/
  7. Shuker, L., Gurnell, A.M., Wharton, G., Gurnell, D.J., England, J., Finn Leeming, B.F., Beach, E. 2017. MoRPh: A citizen science tool for monitoring and appraising physical habitat changes in rivers. Water and Environment Journal, 31, 418-424, DOI: 10.1111/wej.12259.

See the Modular River Survey website (https://modularriversurvey.org/publications/) for additional publications and reports