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Uses and Applications M. Naura & J. Walker RHS Lead Region
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Application Scales
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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
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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
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Prioritise management
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Habitat Quality & Modification in England & Wales Uses: Global overview, Leaps, Other local applications HQAHMI
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LEAP QUALITY ASSESSMENT
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Identify catchment issues
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Catchment scale application The Sankey Now Project n Aims –Natural asset register –State of the environment –Management priorities
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RHS site distribution in the Sankey catchment n=125
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Management impact n = 125 n = 4569
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Determining a Sub-set of Similar Reference Sites Low altitude/Low slopeHigh altitude/High slope High energy Low energy
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n = 125 n = 277n = 4569
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Gen. Info: Landuse in the Sankey Catchment l Wooded l Agricultural l Semi-rural l Urban
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Define strategy tailored to catchment and management needs
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River Rehabilitation
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n ISSUE –Habitat Modification n RESPONSE –River restoration n form, processes –River rehabilitation n mimic natural form –Habitat enhancement n cosmetic improvements STRATEGY ?
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Criteria for selection n Low Existing Geomorphological Diversity n Moderate-High Stream Power n High Existing Modification
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Criteria Used to Assess Rehabilitation Potential
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Geomorphological Diversity l 0 l 1-4 l 5-9 l 10-14 l 15-19 l 20-30
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Stream Power n Minimal n Very low n Low n Moderate n High n Very high
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Habitat Modification l Pristine l Semi-natural l Predominately unmodified l Obviously modified l Significantly modified l Heavily/extensive modification
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Applying the Work to the Field Fisheries interest in riffle rehabilitation first choice: River Weaver
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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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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
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Sites with Rehabilitation Potential l RHS Sites l Potential general rehabilitation sPotential rehabilitation for fisheries
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Black Brook Site Prior to Rehabilitation
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Black Brook Site Post- Rehabilitation (Artist’s Impression)
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Work in Progress at the Black Brook Site
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Treat problem at source
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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
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Typical Section of Mersey in S. Manchester 100% Resectioned & bermed, straightened, widened, predominant glide, silty substrate
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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
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Removing Fine Sediments From Banks and Berms
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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
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Sampling strategy n Random sample of 20% of classified river n Geomorphological inter-reach survey
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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?
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Benefits n Flood Defence –Reduction of maintenance needs –Reduction of scheme design n Conservation –Reduction of environmental impact –Potential wetland restoration
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Erosion
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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 ?
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Occurrence of Key RHS Habitat Features at the Keekle
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Predicting species distribution
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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
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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
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Distribution of Habitat Variables l 0 variables l 1 variable l 2 variables l 3 variables l 4 variables
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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
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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)
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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
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Pilot Study on The River Nidd n Continuous fisheries and RHS surveys n Analysis of fish community distribution n Predictive models
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Distribution of R. Nidd Coarse Fish Communities
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Substrate Distribution on the Nidd
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Coarse Fish Community Distribution in Yorkshire Rivers
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Prediction of Coarse Fish Community Distribution According to Altitude and Distance from Source
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Predicted Community Types in Yorkshire Rivers
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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?
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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
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Sample of combined RHS/Crayfish surveys
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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
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Crayfish Features with Positive and Negative Influences n MODEL SUCCESS: 95%
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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
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Discriminant Analysis on Crayfish Occurrence According to Transformed Altitude, Slope and Distance from Source
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Model relevance and applicability
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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
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That’s all Folks !
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