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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 M. Naura & J. Walker RHS Lead Region
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
Aims • Prioritise management • Integrate function management for Catchment Issues • Identify catchment issues • Define strategy tailored to catchment and management needs • Treat problem at source
Habitat Quality & Modification in England & Wales Uses: Global overview, Leaps, Other local applications HQA HMI
Catchment scale applicationThe Sankey Now Project • Aims • Natural asset register • State of the environment • Management priorities
Management impact n = 125 n = 4569
Determining a Sub-set of Similar Reference Sites High energy Low energy Low altitude/Low slope High altitude/High slope
n = 125 n = 277 n = 4569
Wooded Agricultural Semi-rural Urban Gen. Info: Landuse in the Sankey Catchment
ISSUE • Habitat Modification • RESPONSE • River restoration • form, processes • River rehabilitation • mimic natural form • Habitat enhancement • cosmetic improvements STRATEGY ?
Criteria for selection • Low Existing Geomorphological Diversity • Moderate-High Stream Power • High Existing Modification
0 1-4 5-9 10-14 15-19 20-30 Geomorphological Diversity
Stream Power • Minimal • Very low • Low • Moderate • High • Very high
Pristine Semi-natural Predominately unmodified Obviously modified Significantly modified Heavily/extensive modification Habitat Modification
Applying the Work to the Field Fisheries interest in riffle rehabilitation first choice: River Weaver
% Gravel and/or Cobble 0-10 10-20 20-30 30-40 40-60 60-80 80-100 Substrate Type
Conclusions • Weaver has few natural riffles • Predominantly sand-bed river system • Recommend against introduction • Suggest alternative sites that are more suitable
RHS Sites Potential general rehabilitation Potential rehabilitation for fisheries Sites with Rehabilitation Potential
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
Typical Section of Mersey in S. Manchester 100% Resectioned & bermed, straightened, widened, predominant glide, silty substrate
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
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
Sampling strategy • Random sample of 20% of classified river • Geomorphological inter-reach survey
Inter-reach fluvial audit • Quantity and type of erosion and deposition • Causes (natural or artificial) of erosion or deposition • Additional potential for wetland restoration?
Benefits • Flood Defence • Reduction of maintenance needs • Reduction of scheme design • Conservation • Reduction of environmental impact • Potential wetland restoration
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 ?
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
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
0 variables 1 variable 2 variables 3 variables 4 variables Distribution of Habitat Variables