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Uses and Applications

Uses and Applications. M. Naura & J. Walker RHS Lead Region. Application Scales. Flood Defence Obectives. Fisheries Obectives. Flood Defence issue Channel capacity. Fisheries issue No fish. Catchment Issue Accelerated Erosion. Local authorities Issues. Anglers Issues.

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Uses and Applications

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  1. Uses and Applications M. Naura & J. Walker RHS Lead Region

  2. Application Scales

  3. Flood Defence Obectives Fisheries Obectives Flood Defence issue Channel capacity Fisheries issue No fish Catchment Issue Accelerated Erosion Local authorities Issues Anglers Issues Local Authorities Agenda Anglers Agenda

  4. Aims • Prioritise management • Integrate function management for Catchment Issues • Identify catchment issues • Define strategy tailored to catchment and management needs • Treat problem at source

  5. Prioritise management

  6. Habitat Quality & Modification in England & Wales Uses: Global overview, Leaps, Other local applications HQA HMI

  7. LEAP QUALITY ASSESSMENT

  8. Identify catchment issues

  9. Catchment scale applicationThe Sankey Now Project • Aims • Natural asset register • State of the environment • Management priorities

  10. RHS site distributionin the Sankey catchment n=125

  11. Management impact n = 125 n = 4569

  12. Determining a Sub-set of Similar Reference Sites High energy Low energy Low altitude/Low slope High altitude/High slope

  13. n = 125 n = 277 n = 4569

  14. Wooded Agricultural Semi-rural Urban Gen. Info: Landuse in the Sankey Catchment

  15. Define strategy tailored to catchment and management needs

  16. River Rehabilitation

  17. ISSUE • Habitat Modification • RESPONSE • River restoration • form, processes • River rehabilitation • mimic natural form • Habitat enhancement • cosmetic improvements STRATEGY ?

  18. Criteria for selection • Low Existing Geomorphological Diversity • Moderate-High Stream Power • High Existing Modification

  19. Criteria Used to Assess Rehabilitation Potential

  20. 0 1-4 5-9 10-14 15-19 20-30 Geomorphological Diversity

  21. Stream Power • Minimal • Very low • Low • Moderate • High • Very high

  22. Pristine Semi-natural Predominately unmodified Obviously modified Significantly modified Heavily/extensive modification Habitat Modification

  23. Applying the Work to the Field Fisheries interest in riffle rehabilitation first choice: River Weaver

  24. % Gravel and/or Cobble 0-10 10-20 20-30 30-40 40-60 60-80 80-100 Substrate Type

  25. Conclusions • Weaver has few natural riffles • Predominantly sand-bed river system • Recommend against introduction • Suggest alternative sites that are more suitable

  26. RHS Sites Potential general rehabilitation Potential rehabilitation for fisheries Sites with Rehabilitation Potential

  27. Black BrookSite Prior toRehabilitation

  28. Black BrookSite Post-Rehabilitation(Artist’sImpression)

  29. Work in Progress at the Black Brook Site

  30. Treat problem at source

  31. RHS Contribution to the Mersey Flood Alleviation Scheme • Flood Defence Aim • assess existing defences provide increased levels of service • Our aim • promote integrated river basin management • reduce environmental impacts of the scheme

  32. Typical Section of Mersey in S. Manchester 100% Resectioned & bermed, straightened, widened, predominant glide, silty substrate

  33. Problems at the site • Fine sediment problem • channel accumulation - loss of capacity • accumulation on berms and at bank toe - stability of embankments • Lack of Habitat Diversity • Homogenous bank habitat, limited flow type diversity, few in-channel features, regular heavy maintenance

  34. Removing Fine Sediments From Banks and Berms

  35. The Role of RHS • Fine sediment problem • Catchment audit to identify sediment sources • Suggest catchment management techniques to reduce inputs. • Flooding problem • Identify potential flood storage areas upstream

  36. Sampling strategy • Random sample of 20% of classified river • Geomorphological inter-reach survey

  37. Inter-reach fluvial audit • Quantity and type of erosion and deposition • Causes (natural or artificial) of erosion or deposition • Additional potential for wetland restoration?

  38. Benefits • Flood Defence • Reduction of maintenance needs • Reduction of scheme design • Conservation • Reduction of environmental impact • Potential wetland restoration

  39. Erosion

  40. Site Based Analysis - The River Keekle • Headwaters of Keekle - planning application for open cast coal mine • Regional conservation designations, but habitat value of the site in a national context ?

  41. Occurrence of Key RHS Habitat Features at the Keekle

  42. Predicting species distribution

  43. Assessing the County of Sussex for Watervole Habitat • S. Region Conservation staff requested details of occurrence and distribution of factors which comprise good watervole habitat • Factors were defined by S. Region, and mapped by the Lead Region Team

  44. Habitat Suitability Variables • Suitability defined according to factors: • Slow flowing water • Steep/soft banks • Not heavily shaded • Extensive marginal vegetation • Land use is not heavily grazed • Simple banktop vegetation

  45. 0 variables 1 variable 2 variables 3 variables 4 variables Distribution of Habitat Variables

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