A12. Urban River Survey

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1. Introduction[edit]

The Urban River Survey (URS) is a scientific assessment method and suite of tools that supports the work of river practitioners including managers in urban environments and other heavily modified landscape settings. The survey is also available to volunteer groups who are engaged with river project officers within an urban or heavily modified landscape setting. The survey, which is a development of the River Habitat Survey, records information on the physical structure and processes of stretches of urban river, typically 500 m in length, that conform to a single engineering type.

2. Objectives[edit]

  • To record information on the broad physical structure and human interventions and pressures on stretches of (sub)urban river that are typically 500 m in length but must be of a single engineering type.
  • To generate indices from the survey data that indicate the relative physical quality of individual surveyed stretches within the range achievable in an urban environment and assign stretches to different classes according to their Habitat Quality.

3. Method summary[edit]

Guidance on Health and Safety while conducting URS surveys is provided during training courses and is presented in the URS Manual. Surveyors are required to adhere to their organisation’s detailed Health and Safety procedures when undertaking MoRPh surveys, which should be conducted from the river’s bank tops.

The first stage in conducting a survey is to identify the stretch to be surveyed. Stretches are typically between 300 and 500 m in length but must reflect a single engineering type. The stretch engineering type is determined from the character of three river channel properties: cross-profile, planform, level of reinforcement. Each of these is determined by walking along the stretch and then assigning it to cross-profile, planform and reinforcement categories, reflecting their respective degree of human modification from semi-natural to fully modified. In addition, an appropriate location for determining representative channel dimensions is identified during this first walkover stage.

Once the stretch length, end points and location for recording channel dimensions have been determined, observations are recorded on a 4 page form. The first page captures general information on the surveyor, survey date, survey location (including National Grid Reference or latitude-longitude of the upstream and downstream ends of the stretch), stretch length and engineering type. Once surveyed, channel dimensions are also recorded on this survey sheet. Up to four photographs can be uploaded into the Information system to accompany each survey. These are supported by comments on photograph locations and contents.

The remaining three survey pages are completed during two further walks along the stretch. During the second walkover, channel dimensions are recorded at the chosen, representative site and information is recorded on physical habitat and vegetation structure at ten equally-spaced spot check locations. The locations (NGR, latitude-longitude) of the spot checks and channel dimension survey can also be recorded. The third walkover captures cumulative measurements along the entire length of the stretch relating to human interventions (bank and bed reinforcement materials and extent, bank profiles, artificial features, non-native invasive plant species, recent management activities, visual indicators of pollution) and natural processes and habitats (evidence of channel dynamics, habitat features and flow types, special features including tree-relayed features).

4. Limitations[edit]

  • As for all habitat surveys of this type, surveyor bias/error and subjectivity may affect some data.
  • URS is appropriate for providing a broad overview of the physical character of urban rivers and the degree to which they are affected by human interventions but it does not deliver sufficient detail or precision to support monitoring of changes within a stretch unless the changes are substantial.

5. Recommendation for method application[edit]

  • Most usefully applied at reasonably wide spacings across a river network to capture broad spatial variations in river physical character as well as contrasts among stretches of different engineering type.
  • Ensure accurate recording of the upstream and downstream ends of surveyed stretches (NGR or latitude-longitude) so that the stretch can be relocated with reasonable precision.
  • Undertake surveys in spring or autumn if possible
  • Survey at low flow to ensure bed visibility and thus reliable surveys of the bed and lower bank faces.

6. Costs[edit]

Enquiries regarding current training costs and opportunities can be made via the URS website (https://urbanriversurvey.org/training/).

7. Data analysis[edit]

All trained surveyors are provided with a log-in to the URS Information System so that they can upload, download, query and map any of the survey data within the URS workspace. Raw survey data and photographs can all be downloaded for analysis from this workspace. In addition, the Information System generates values of over 50 indices representing different properties of each surveyed stretch and four summary classifications. Classifications of the (i) Materials, (ii) Physical Habitat and (iii) Vegetation characteristics of individual river stretches are combined to provide (iv) an integrative Stretch Habitat Quality index. Values of the indices and the assigned classes for each surveyed stretch can be mapped and downloaded for further analysis.

8. Examples[edit]

The URS is currently being used within Thames Water’s River Crane Smarter Water Catchment programme. It forms part of a multi-scale framework that has been developed for assessing the physical condition of a catchment river network and identifying opportunities for river restoration (https://www.cranevalley.org.uk/smarter-water-catchments/).

9. More information[edit]

10. References[edit]

  1. Davenport, A.J., Gurnell, A.M., Armitage, P.D., 2001. Classifying urban rivers. Water Science and Technology, 43, 9, 147-156, ISSN: 0273-1223.
  2. Davenport, A.J., Gurnell, A.M., Armitage, P.D., 2004. Habitat survey and classification of urban rivers. River Research and Applications, 20, 687-704, DOI: 10.1002/rra.785.
  3. Boitsidis, A.J., Gurnell, A.M., Scott, M., Petts, G.E., Armitage, P.D., 2006. Decision support system for identifying the habitat quality and rehabilitation potential of urban rivers. Water and Environment Journal, 20, 130-140, DOI: 10.1111/j.1747-6593.2005.00005.x.
  4. Gurnell, A.M., Lee, M., Souch, C., 2007. Urban rivers: Hydrology, Geomorphology, Ecology and Opportunities for Change. Geography Compass 1, 1118–1137, DOI: 10.1111/j.1749-8198.2007.00058.x
  5. Shuker, L., Gurnell, A.M., Raco, M., 2011. Some simple tools for communicating the biophysical condition of urban rivers to support high-level discussions regarding river restoration. Urban Ecosystem, 15: 389-408, DOI: 10.1007/s11252-011-0207-2.
  6. Gurnell, A.M., Shuker, L., Lee, M., Boitsidis, A., 2012. Gradients in the biophysical structure of urban rivers and their association with river channel engineering. River Research and Applications, 28, 908-925, DOI: 10.1002/rra.1487..
  7. Shuker, L., Moggridge, H., Gurnell, A.M., 2015. Assessment of hydromorphology following restoration measures in heavily modified rivers: illustrating the potential contribution of the Urban River Survey to Water Framework Directive investigations. Area, 47(4), 396-407, DOI: 10.1111/area.12185.