eamont rhs team, environment agency catchment …...joanne barlow & kate cooper rrc annual...
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Joanne Barlow & Kate Cooper
RRC Annual Network Conference 2004, Durham 1
Integrating Geomorphological and Integrating Geomorphological and River Habitat Surveys (RHS) at a River Habitat Surveys (RHS) at a
catchment scalecatchment scaleIdentifying the potential restoration of Identifying the potential restoration of GoldrillGoldrill
BeckBeck
Joanne Barlow and Kate Cooper
RHS Team, Environment Agency
PRESENTATION OUTLINEPRESENTATION OUTLINE______________________________________________________________________________________________________________________________________________________________________________________________
• Introduction• Field Methodology• Data Analysis• Identification of pressures & impacts• Conclusions & Future Developments
GOLDRILL BECK GOLDRILL BECK ((EamontEamont Catchment)Catchment)________________________________________________________________________________________________________________________________________________________________________________________________
• Upland catchment in Lake District
• Land-use: predominately rural and agricultural pasture
Goldrill BeckCatchment
UllswaterGoldrill Beck Catchment
Goldrill Beck river network
Lake
Urban area
• Historical flood defence management
• Historical mining and gravel extraction
PROJECT AIMPROJECT AIM______________________________________________________________________________________________________________________________________________________________________________________________
• ‘To evaluate habitat quality and geomorphological features within the GoldrillBeck study area in order to identify pressures on the system and derive options for future management’
• Report commissioned by the Environment Agency Fisheries Team in NW Region, North Area
Joanne Barlow & Kate Cooper
RRC Annual Network Conference 2004, Durham 2
FIELD METHODOLOGYFIELD METHODOLOGY________________________________________________________________________________________________________________________________________________________________________________________________
• River Habitat Survey - 66 sites each 500 m in length, providing ~ 50% coverage of river network
• Geomorphological Survey - 60 km of river surveyed in 121 reaches, providing 90% coverage
• Data collection was by Babtie, Brown and Root in 2002
SURVEY SITE LOCATIONSSURVEY SITE LOCATIONS________________________________________________________________________________________________________________________________________________________________________________________________
N.B.
• Spots indicate survey midpoint
• Geomorphological Surveys were not completed on Dovedale/CaudaleBecks due to adverse weather
DATA ANALYSISDATA ANALYSIS________________________________________________________________________________________________________________________________________________________________________________________________
• Summary statistics to identify presence of nationally rare fluvial features
• Habitat Quality Assessment (HQA) and Habitat Modification Class (HMC) indices
• Flow, substrate and feature diversity indices• Scale and presence of erosion and deposition
features • Identification of geomorphological pressures
RHS RESULTSRHS RESULTS________________________________________________________________________________________________________________________________________________________________________________________________
• HQA and HMC identify sites of poor habitat quality and high levels of channel modification
• HQA sub-scores and Diversity Indices highlight specific reasons for poor habitat quality
• Possible locations for restoration and suggestions for improvements can be made based on these results
Joanne Barlow & Kate Cooper
RRC Annual Network Conference 2004, Durham 3
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25111
25112
2510825110
25164
25162 25153
25166
25146
25122
25117
25116
N
HQA classes
# Very High# Very Poor
0 2Kilometres
HQA AND HMC RESULTSHQA AND HMC RESULTS________________________________________________________________________________________________________________________________________________________________________________________________
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NHMC
# Pristine or semi-natural# Predominantly unmodified# Obviously modified# Significantly modified# Severely modified
0 2Kilometres
• HQA tended to be higher in upland areas, but high quality sites also found on main rivers
• HMC has clearer spatial pattern; main rivers are clearly more modified than tributaries
GEOMORPHOLOGY RESULTSGEOMORPHOLOGY RESULTS______________________________________________________________________________________________________________________________________________________________________________________________
• Erosion sources reveal causes of erosion and quantity of material being removed within reach
• Depositional features highlight areas of extensive deposition/storage of sediment
• Identification of scale of accelerated erosion, fencing quality, grazing pressures and poaching
• Are sediment processes operating ‘naturally’?
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4748 49
84
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# Sites of very high/extreme erosion
# Sites of high/very high deposition
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NFencing Quality - Right Bank� None� Semi-effective� Effective
0 2Kilometres
GEOMORPHOLOGY RESULTSGEOMORPHOLOGY RESULTS__________________________________________________________________________________________________________________________________________________________________________________________________
• High erosion occurs predominantly in steep upland areas
• Depositional features were mainly found in upland valleys
• Erosion was more prevalent than deposition across the catchment as a whole
• Some accelerated erosion due to poor fencing quality
IDENTIFYING RESTORATION IDENTIFYING RESTORATION POTENTIALPOTENTIAL__________________________________________________________________________________________________________________________________________________________________________________________________
• Integration of RHS and Geomorphological survey results
• Upland headwaters: not suitable for restoration, but need to be protected
• Upland valley reaches: ideal sites for restoration due to modifications and lack of bank features
• Specific sites of poor quality targeted, especially where connectivity of system is affected
Joanne Barlow & Kate Cooper
RRC Annual Network Conference 2004, Durham 4
GENERAL MANAGEMENT OPTIONSGENERAL MANAGEMENT OPTIONS__________________________________________________________________________________________________________________________________________________________________________________________________
Management Option ‘Current Risks’ ‘Benefits of Option’ Target Areas Comments
Protection andmaintenance of existinghabitat andgeomorphological quality
♦ Current high qualityhabitats may degradewithout appropriatemonitoring
♦ Further loss of habitator modification
♦ Protection of higherquality habitats
♦ Initially highestquality sites
♦ Throughout studyarea
Protection of wetlandsites
Stock-proof fencing alongriver banks
♦ Continued andincreased poaching,leading to greateraccelerated erosion
♦ Poor bank vegetationstructure
♦ Improved bankvegetation structureand diversity
♦ Reduction ofaccelerated erosion
♦ Improvements tohabitat quality
♦ Specific sitesidentified in Fig. 37.
♦ Sites suffering fromsignificant poaching
Construction of ‘live’ orvegetated barriersinstead of fencing, asmore durable andsustainable alternative inflood risk areas.
Enhancement of artificialbanks and channels interms of materials andchannel morphology.Removal of retainingwalls where applicable
♦ Low diversity of bankand channel features
♦ Poor bank vegetationstructure in highlymodified sites
♦ Enhancement ofbank and channelhabitats
♦ Improvement of RHQ♦ Increase in diversity
of channel and bankfeatures
♦ Sites with significantand severelymodified channels
Collaboration is neededwith Flood Defence onthe need ofembankments andretaining walls for floodmanagement.
Target sites of lowestRHQ for priorityimprovement
♦ Localised low qualitysites reduce theoverall habitat qualityof the wider reach.
♦ Targeting the lowestRHQ sites first willlead to a rapidimprovement inoverall habitat quality
♦ Across the study area
TARGETED RESTORATION EXAMPLETARGETED RESTORATION EXAMPLE______________________________________________________________________________________________________________________________________________________________________________________________________
SITE 25122 (HQA = 5)
Lack of flow features and substrate diversity
SITE 25124 (HQA = 4)
Habitat impact from road bridge
OPTIONS FOR RESTORATION?
• Relax left bank reinforcement to promote sinuosity and deposition features
• Encourage wet woodland on right bank -wood features and leafy debris
• Creation of backwaters/refuges for fish and invertebrates during high flows
CONCLUSIONSCONCLUSIONS________________________________________________________________________________________________________________________________________________________________________________________________
• Integrated use of RHS and geomorphological survey can identify locations and causes of poor river habitat quality, and reaches which are geomorphically viable for restoration
• These sites can then be targeted specifically, or restoration can be approached on a broader catchment scale
FUTURE DEVELOPMENTSFUTURE DEVELOPMENTS__________________________________________________________________________________________________________________________________________________________________________________________________
• Improving GIS-based analysis of RHS and associated data
• GeoRHS: integrating the surveys and extending RHS principles to the floodplain
• River Habitat Objectives (RHOs): a specific methodology for river and catchment appraisal and prioritising restoration options
• For further information please contact [email protected]