uses and applications m. naura & j. walker rhs lead region
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RIVER HABITATSURVEY
Uses and ApplicationsUses and Applications
M. Naura & J. WalkerM. Naura & J. Walker
RHS Lead RegionRHS Lead Region
Application ScalesApplication Scales
Flood DefenceObectives
FisheriesObectives
Flood Defence issueChannel capacity
Fisheries issueNo fish
Catchment IssueCatchment Issue
Accelerated ErosionAccelerated Erosion
Local AuthoritiesAgenda
Local authoritiesIssues
AnglersAgenda
AnglersIssues
AimsAims
Prioritise managementPrioritise management
Integrate Integrate function managementfunction management for for CCatchment Issuesatchment Issues
– Define strategy tailored to catchment Define strategy tailored to catchment and management needsand management needs
– Treat problem at sourceTreat problem at source
– Identify catchment issuesIdentify catchment issues
Prioritise managementPrioritise management
Habitat Quality & Habitat Quality & Modification in England & Modification in England &
WalesWales
Uses: Global overview, Leaps, Other local Uses: Global overview, Leaps, Other local applicationsapplicationsHQA HMI
Sankey / GlazeManagement Evidence
Region: North WestDredging (% Occurrence): 0
Number of Sites: 10Mowing (% Occurrence): 14
Quality Indices Enhancement (% Occurrence): 14
Median GQA: 3 Roadbridges (% Occurrence): 14
Median HMI Index: 4 Poaching (% Occurrence): 10
Average HMI Score: 26 Resectioning (% Occurrence): 60
Average HQA Score: 34 Embanked (% Occurrence):: 29
Land Use OccurrenceArtificial Features
Occurrence of Extensive Woodland (%): 20Culverts (% Occurrence): 20
Occurrence of Extensive Urban Land (%): 50Outfalls (% Occurrence): 40
Weirs (% Occurrence): 10 Occurrence of Extensive Agricultural Land (%): 70
Fords (% Occurrence): 0 Occurrence of Extensive Semi Rural Land(%): 0
LEAP QUALITY ASSESSMENT
Identify catchment issuesIdentify catchment issues
Catchment scale Catchment scale applicationapplication
The Sankey Now ProjectThe Sankey Now Project
AimsAims
– Natural asset registerNatural asset register
– State of the environment State of the environment
– Management prioritiesManagement priorities
RHS site distributionRHS site distributionin the Sankey catchmentin the Sankey catchment
n=125
Management impactManagement impact
0
20
40
60
80
Sankey Whole Reference Network
Significantly/ Severely Modified
Pristine to Predominantly Unmodified
n = 125
n = 4569
Determining a Sub-set of Similar Reference SitesDetermining a Sub-set of Similar Reference Sites
Low altitude/Low slope
High altitude/High slope
High energy
Low energy
0
10
20
30
40
50
60
70
80
Sankey Sub-set ofreference sites
Whole referenceNetwork
Significantly/Severely Modified
Pristine to Predominantly Unmodified
n = 125
n = 277 n = 4569
Gen. Info: Landuse in the Gen. Info: Landuse in the Sankey CatchmentSankey Catchment
WoodedWooded AgriculturalAgricultural Semi-ruralSemi-rural UrbanUrban
Define strategy tailored to Define strategy tailored to catchment and catchment and
management needsmanagement needs
River RehabilitationRiver Rehabilitation
ISSUEISSUE– Habitat ModificationHabitat Modification
RESPONSERESPONSE– River restorationRiver restoration
form, processesform, processes
– River rehabilitationRiver rehabilitation mimic natural formmimic natural form
– Habitat enhancementHabitat enhancement cosmetic improvementscosmetic improvements
STRATEGY ?STRATEGY ?
Criteria for selectionCriteria for selection
Low Existing Geomorphological Low Existing Geomorphological DiversityDiversity
Moderate-High Stream Power Moderate-High Stream Power
High Existing ModificationHigh Existing Modification
Criteria Used to Assess Criteria Used to Assess Rehabilitation PotentialRehabilitation Potential
S lopeD ischarge
W idth
S tream P ow er
E ros ionD epos itionS ubstrate
F low Types
G eom orph . D ivers ity
R ein forced, R esectionedE m banked, B erm s,
C u lverts , A rt. substrate,F ord, P oach ing
H M I
R eha bilita tion Potentia l Loca tion Ma p
Geomorphological Geomorphological DiversityDiversity
00 1-41-4 5-95-9 10-1410-14 15-1915-19 20-3020-30
Stream PowerStream Power MinimalMinimal Very lowVery low LowLow ModerateModerate HighHigh Very highVery high
Habitat ModificationHabitat Modification PristinePristine Semi-naturalSemi-natural Predominately Predominately
unmodifiedunmodified Obviously Obviously
modifiedmodified Significantly Significantly
modifiedmodified Heavily/Heavily/
extensive extensive modificationmodification
Applying the Work to the Applying the Work to the Field Field
Fisheries interest in riffle rehabilitationFisheries interest in riffle rehabilitation
first choice:first choice:
River WeaverRiver Weaver
Substrate TypeSubstrate Type
% Gravel % Gravel and/or and/or CobbleCobble
0-100-10 10-2010-20 20-3020-30 30-4030-40 40-6040-60 60-8060-80 80-10080-100
Substrate Analysis of Weaver and Occurrenceof Riffles, Compared to National and RegionalMean Averages
Substage Type National Regional Weaver
Bed Rock 3.2 6.6 2.9
Boulders 3.8 8.2 0.2
Cobbles 14.3 26.9 8.9
Gravel/Pebble 34.0 22.2 22.9
Sand 5.5 9.6 33.1
Silt 20.3 15.3 21.3
Clay 4.3 0.5 0
No. of Riffles 5.35 4.52 3.91
ConclusionsConclusions
Weaver has few natural rifflesWeaver has few natural riffles Predominantly sand-bed river Predominantly sand-bed river
systemsystem
Recommend against introductionRecommend against introduction Suggest alternative sites that are Suggest alternative sites that are
more suitablemore suitable
Sites with Rehabilitation Sites with Rehabilitation PotentialPotential
RHS SitesRHS Sites Potential Potential
general general rehabilitationrehabilitation
Potential Potential rehabilitation rehabilitation for fisheriesfor fisheries
Black BrookBlack BrookSite Prior toSite Prior toRehabilitationRehabilitation
Black BrookBlack BrookSite Post-Site Post-RehabilitationRehabilitation(Artist’s(Artist’sImpression)Impression)
Work in Progress at the Work in Progress at the Black Brook SiteBlack Brook Site
Treat problem at sourceTreat problem at source
RHS Contribution to the Mersey RHS Contribution to the Mersey Flood Alleviation SchemeFlood Alleviation Scheme
Flood Defence AimFlood Defence Aim– assess existing defences provide assess existing defences provide
increased levels of serviceincreased levels of service Our aimOur aim
– promote integrated river basin promote integrated river basin managementmanagement
– reduce environmental impacts of the reduce environmental impacts of the schemescheme
Typical Section of Mersey Typical Section of Mersey in S. Manchesterin S. Manchester
100% Resectioned & bermed,straightened, widened,predominant glide, silty
substrate
Problems at the siteProblems at the site
Fine sediment problemFine sediment problem– channel accumulation - loss of channel accumulation - loss of
capacitycapacity– accumulation on berms and at bank accumulation on berms and at bank
toe - stability of embankmentstoe - stability of embankments Lack of Habitat DiversityLack of Habitat Diversity
– Homogenous bank habitat, limited Homogenous bank habitat, limited flow type diversity, few in-channel flow type diversity, few in-channel features, regular heavy maintenancefeatures, regular heavy maintenance
Removing Fine Sediments Removing Fine Sediments From Banks and BermsFrom Banks and Berms
The Role of RHSThe Role of RHS
Fine sediment problemFine sediment problem– Catchment audit to identify sediment Catchment audit to identify sediment
sourcessources– Suggest catchment management Suggest catchment management
techniques to reduce inputs. techniques to reduce inputs.
Flooding problemFlooding problem– Identify potential flood storage areas Identify potential flood storage areas
upstreamupstream
Sampling strategySampling strategy
Random sample of 20% of Random sample of 20% of classified riverclassified river
Geomorphological inter-reach Geomorphological inter-reach surveysurvey
Inter-reach fluvial auditInter-reach fluvial audit
Quantity and type of erosion and Quantity and type of erosion and depositiondeposition
Causes (natural or artificial) of Causes (natural or artificial) of erosion or depositionerosion or deposition
Additional potential for wetland Additional potential for wetland restoration? restoration?
BenefitsBenefits
Flood DefenceFlood Defence– Reduction of maintenance needsReduction of maintenance needs– Reduction of scheme designReduction of scheme design
ConservationConservation– Reduction of environmental impactReduction of environmental impact– Potential wetland restorationPotential wetland restoration
ErosioErosionn
Site Based Analysis - The River Site Based Analysis - The River KeekleKeekle
Headwaters of Keekle - planning Headwaters of Keekle - planning application for open cast coal mineapplication for open cast coal mine
Regional conservation Regional conservation designations, but habitat value of designations, but habitat value of the site in a national context ?the site in a national context ?
Occurrence of Key RHS Occurrence of Key RHS Habitat Features at the Habitat Features at the
KeekleKeekleFEATURE Occurrence on 4
Keekle sites% occurrence at thenational level
% occurrence atthe regional level
Marsh 4 7.54 9.52
Carr 1 3.49 0.68
Flush 2 4.31 4.76
Debris Dam 3 18.24 9.52
Wetland Extensive 2 2.65 1.81
Natural Open Water 1 3.7 2.5
Debrisdam+Marsh+Flush+Carr
1 0.07 (2/3046) 0
Debris dam+Marsh+Flush 2 0.36 (11/3046) 0.0034
Debris dam+Marsh 1 1.64 (50/3046) 0.006
Predicting species Predicting species distributiondistribution
Assessing the County of Assessing the County of Sussex for Watervole Sussex for Watervole
HabitatHabitat
S. Region Conservation staff S. Region Conservation staff requested details of occurrence requested details of occurrence and distribution of factors which and distribution of factors which comprise good watervole habitatcomprise good watervole habitat
Factors were defined by S. Region, Factors were defined by S. Region, and mapped by the Lead Region and mapped by the Lead Region TeamTeam
Habitat Suitability Habitat Suitability VariablesVariables
Suitability defined according to Suitability defined according to factors:factors:– Slow flowing waterSlow flowing water– Steep/soft banksSteep/soft banks– Not heavily shadedNot heavily shaded– Extensive marginal vegetationExtensive marginal vegetation– Land use is not heavily grazedLand use is not heavily grazed– Simple banktop vegetationSimple banktop vegetation
Distribution of Habitat Distribution of Habitat VariablesVariables
0 variables0 variables 1 variable1 variable 2 variables2 variables
3 variables 3 variables 4 variables4 variables
FindingsFindings
Unfortunately few sites with most Unfortunately few sites with most or all of the required habitat or all of the required habitat variablesvariables
However S. Region Conservation However S. Region Conservation staff confirmed that of the 6 sites staff confirmed that of the 6 sites with 3 or 4 variables present 4 had with 3 or 4 variables present 4 had recorded watervole sightingsrecorded watervole sightings
Project DevelopmentsProject Developments
The information produced will now The information produced will now be used to considerbe used to consider– Habitat improvement workHabitat improvement work– Potential watervole introductionsPotential watervole introductions
Problem for reintroduction, and for Problem for reintroduction, and for RHS analysis - occurrence of Mink RHS analysis - occurrence of Mink
Technique applicable to any speciesTechnique applicable to any species– similar habitat review for water shrews similar habitat review for water shrews
(national application)(national application)
Coarse Fisheries Coarse Fisheries ApplicationApplication
Aim: to develop predictive tools to Aim: to develop predictive tools to better target North East fisheries better target North East fisheries rolling programmerolling programme– Identification of community typesIdentification of community types– Identification of community habitatsIdentification of community habitats– Prediction of community types Prediction of community types
according toaccording to habitat features (RHS)habitat features (RHS) map-derived variablesmap-derived variables
Pilot Study on The River Pilot Study on The River NiddNidd
Continuous fisheries and RHS Continuous fisheries and RHS surveyssurveys
Analysis of fish community Analysis of fish community distributiondistribution
Predictive modelsPredictive models
Distribution of R. Nidd Distribution of R. Nidd Coarse Fish CommunitiesCoarse Fish Communities
SubstrateSubstrateDistributionDistributionon the Niddon the Nidd
Coarse Fish Community Coarse Fish Community Distribution in Yorkshire Distribution in Yorkshire
RiversRivers
Prediction of Coarse Fish Prediction of Coarse Fish Community Distribution Community Distribution
According to Altitude and According to Altitude and Distance from SourceDistance from Source
Trout/ Grayling Gudgeon Roach/Perch
Constant -26.7 -22.2 -25.8
Altitude 3.3 2.6 2.6
Distancefrom Source
4.21 4.3 4.8
% SUCCESS = 65%
Predicted Community Predicted Community Types in Yorkshire RiversTypes in Yorkshire Rivers
ConclusionConclusion
Fish community distribution can be Fish community distribution can be predicted from site data (RHS) predicted from site data (RHS)
Fish community distribution can be Fish community distribution can be predicted from Map datapredicted from Map data
Prediction of species distribution?Prediction of species distribution?
The Native CrayfishThe Native Crayfish
Endangered species whose Endangered species whose distribution is limited bydistribution is limited by– competition by introduced alien competition by introduced alien
speciesspecies– fungal disease: the crayfish plaguefungal disease: the crayfish plague
Aim:Aim:– to predict habitat suitability for to predict habitat suitability for
crayfish using RHScrayfish using RHS
Sample of combined Sample of combined RHS/Crayfish surveysRHS/Crayfish surveys
Use of RHS to Predict the Use of RHS to Predict the Occurrence of the Native Occurrence of the Native
CrayfishCrayfish
Pairing of existing RHS sites with Pairing of existing RHS sites with crayfish datacrayfish data– Average distance between sites = 1.7kmAverage distance between sites = 1.7km
Selection of a subset of variablesSelection of a subset of variables– First selection - Chi-square & Mann-First selection - Chi-square & Mann-
WhitneyWhitney– Second selection using logistic regressionSecond selection using logistic regression
Crayfish Features with Crayfish Features with Positive and Negative Positive and Negative
InfluencesInfluencesPositive Influence Negative Influence
Exposed Boulders Cobble substrate
Riffles (Number) Gravel/pebble/sandbanks
Boulder Cobble Banks Eroding cliffs
Overhanging Boughs Poached banks
Tree Shading Reinforced banks
Exposed tree roots
MODEL SUCCESS: 95%MODEL SUCCESS: 95%
Three ecological Three ecological dimensionsdimensions
COVERCOVER– Exposed bouldersExposed boulders
FOODFOOD– RifflesRiffles– Tree shading, overhanging boughsTree shading, overhanging boughs
EROSIONEROSION– Poached banksPoached banks– Gravel/sand banksGravel/sand banks– Eroding cliffsEroding cliffs– Reinforced toeReinforced toe
Discriminant Analysis on Discriminant Analysis on Crayfish Occurrence Crayfish Occurrence
According to Transformed According to Transformed Altitude, Slope and Altitude, Slope and
Distance from SourceDistance from SourceCrayfishabsent
Crayfishpresent
Constant -29.067 -28.054
Altitude 5.900 4.879
Slope 2.605 4.862
Distancefrom Source
15.087 15.657
% SUCCESS = 70%
Model relevance and Model relevance and applicabilityapplicability
RIVER HABITATSURVEY
Implementing RHSImplementing RHS
RHS has extensive national, regional, RHS has extensive national, regional, catchment and site based applicationcatchment and site based application
RHS is a multi-functional tool that can RHS is a multi-functional tool that can be used for delivering integrated river be used for delivering integrated river basin managementbasin management
That’s all Folks !That’s all Folks !