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

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Presentation on theme: "Uses and Applications M. Naura & J. Walker RHS Lead Region."— Presentation transcript:

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

5 Application Scales

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

7 Aims n Prioritise management n Integrate function management for Catchment Issues –Define strategy tailored to catchment and management needs –Treat problem at source –Identify catchment issues

8 Prioritise management

9 Habitat Quality & Modification in England & Wales Uses: Global overview, Leaps, Other local applications HQAHMI

10 LEAP QUALITY ASSESSMENT

11 Identify catchment issues

12 Catchment scale application The Sankey Now Project n Aims –Natural asset register –State of the environment –Management priorities

13 RHS site distribution in the Sankey catchment n=125

14 Management impact n = 125 n = 4569

15 Determining a Sub-set of Similar Reference Sites Low altitude/Low slopeHigh altitude/High slope High energy Low energy

16 n = 125 n = 277n = 4569

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

18 Define strategy tailored to catchment and management needs

19 River Rehabilitation

20 n ISSUE –Habitat Modification n RESPONSE –River restoration n form, processes –River rehabilitation n mimic natural form –Habitat enhancement n cosmetic improvements STRATEGY ?

21 Criteria for selection n Low Existing Geomorphological Diversity n Moderate-High Stream Power n High Existing Modification

22 Criteria Used to Assess Rehabilitation Potential

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

24 Stream Power n Minimal n Very low n Low n Moderate n High n Very high

25 Habitat Modification l Pristine l Semi-natural l Predominately unmodified l Obviously modified l Significantly modified l Heavily/extensive modification

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

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

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

30 Sites with Rehabilitation Potential l RHS Sites l Potential general rehabilitation sPotential rehabilitation for fisheries

31 Black Brook Site Prior to Rehabilitation

32 Black Brook Site Post- Rehabilitation (Artist’s Impression)

33 Work in Progress at the Black Brook Site

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36 Treat problem at source

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

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

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

40 Removing Fine Sediments From Banks and Berms

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

42 Sampling strategy n Random sample of 20% of classified river n Geomorphological inter-reach survey

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

44 Benefits n Flood Defence –Reduction of maintenance needs –Reduction of scheme design n Conservation –Reduction of environmental impact –Potential wetland restoration

45 Erosion

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

47 Occurrence of Key RHS Habitat Features at the Keekle

48 Predicting species distribution

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

50 Habitat Suitability Variables n 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

51 Distribution of Habitat Variables l 0 variables l 1 variable l 2 variables l 3 variables l 4 variables

52 Findings n Unfortunately few sites with most or all of the required habitat variables n However S. Region Conservation staff confirmed that of the 6 sites with 3 or 4 variables present 4 had recorded watervole sightings

53 Project Developments n The information produced will now be used to consider – Habitat improvement work – Potential watervole introductions n Problem for reintroduction, and for RHS analysis - occurrence of Mink n Technique applicable to any species – similar habitat review for water shrews (national application)

54 Coarse Fisheries Application n Aim: to develop predictive tools to better target North East fisheries rolling programme –Identification of community types –Identification of community habitats –Prediction of community types according to n habitat features (RHS) n map-derived variables

55 Pilot Study on The River Nidd n Continuous fisheries and RHS surveys n Analysis of fish community distribution n Predictive models

56 Distribution of R. Nidd Coarse Fish Communities

57 Substrate Distribution on the Nidd

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59 Coarse Fish Community Distribution in Yorkshire Rivers

60 Prediction of Coarse Fish Community Distribution According to Altitude and Distance from Source

61 Predicted Community Types in Yorkshire Rivers

62 Conclusion n Fish community distribution can be predicted from site data (RHS) n Fish community distribution can be predicted from Map data ø Prediction of species distribution?

63 The Native Crayfish n Endangered species whose distribution is limited by –competition by introduced alien species –fungal disease: the crayfish plague n Aim: –to predict habitat suitability for crayfish using RHS

64 Sample of combined RHS/Crayfish surveys

65 Use of RHS to Predict the Occurrence of the Native Crayfish n Pairing of existing RHS sites with crayfish data – Average distance between sites = 1.7km n Selection of a subset of variables –First selection - Chi-square & Mann-Whitney – Second selection using logistic regression

66 Crayfish Features with Positive and Negative Influences n MODEL SUCCESS: 95%

67 Three ecological dimensions n COVER –Exposed boulders n FOOD –Riffles –Tree shading, overhanging boughs n EROSION –Poached banks –Gravel/sand banks –Eroding cliffs –Reinforced toe

68 Discriminant Analysis on Crayfish Occurrence According to Transformed Altitude, Slope and Distance from Source

69 Model relevance and applicability

70 Implementing RHS n RHS has extensive national, regional, catchment and site based application n RHS is a multi-functional tool that can be used for delivering integrated river basin management

71 That’s all Folks !


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