Transcript River Habitat Survey - Aristotle University of Thessaloniki
RIVER HABITAT SURVEY
Uses and Applications Marc Naura & Mark Diamond RHS Lead Region
River Habitat Survey
Aims A standard field methodology objective statistically robust widely applicable practicable: target time, 1 hour
Objective B Bar bar exposed under low flows ‘No perceptible flow’ in deeper pool A A B Unbroken standing waves observed as shallow flow over riffle
Statistically robust Survey structure – – – – use of transects survey length spacing of transects sweep-up Between surveyor variability reduced – – simple choices tests on different river types
Widely applicable
RHS form: Two main sections
SPOT-CHECKS SWEEP-UP
Features recorded EROSION – eroding/stable cliffs DEPOSITION – side/point/mid channel bars VEGETATION STRUCTURE – channel & banks FLOW – 10 Flow types
Other features BANK PROFILES – natural: undercut...gentle
– modified: resectioned..embanked
TREES – extent & associated features CHANNEL FEATURES – – waterfall,riffles/pools etc.
boulders, exposed sediment LAND USE (50m) – 13 land use categories
Management features MANAGEMENT – resectioning/reinforcement – poaching (trampling) ROADS & BRIDGES FLOW REGULATION – weir/sluices/culverts
Baseline survey network From 1994 to 1996
England and Wales 4569 sites Scotland 779 sites Northern Ireland 266 sites
Habitat modification score (HMS) categories
0
0 - 2 3 - 8 9 - 20 21 - 44 45 or more
Pristine
Semi-natural Predominantly unmodified Obviously modified Significantly modified Severely modified
Footnote: semi-natural includes pristine channels
25
Example:assessment of Lowland low energy site with an HQA=65
20 15 10 5 0 0 to 10 10 to 20 20 to 30 30 to 40 40 to 50 50 to 60 60 to 70 70+
Distribution of HQA for nearest neighbour sites on PCA map
Application Scales
Flood Defence Obectives Flood Defence issue Channel capacity Fisheries Obectives Fisheries issue No fish Local authorities Issues
Catchment Issue Accelerated Erosion
Local Authorities Agenda Anglers Issues 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
Prioritise management
Habitat Quality & Modification in England & Wales Uses: Global overview, Leaps, Other local applications HQA HMI
LEAP QUALITY ASSESSMENT
Sankey / Glaze
Region: North West
Number of Sites:
10
Quality Indices Median GQA: Median HMI Index: Average HMI Score: Average HQA Score:
3 4 26 34
Management Evidence Dredging (% Occurrence): Mowing (% Occurrence): Enhancement (% Occurrence): Roadbridges (% Occurrence): Poaching (% Occurrence): Resectioning (% Occurrence): Embanked (% Occurrence)::
0 14 14 14 10 60 29
Artificial Features Culverts (% Occurrence): Outfalls (% Occurrence): Weirs (% Occurrence): Fords (% Occurrence): Land Use Occurrence Occurrence of Extensive Woodland (%):
20
Occurrence of Extensive Urban Land (%):
40 10 0
Occurrence of Extensive Agricultural Land (%): Occurrence of Extensive Semi Rural Land(%):
20 50 70 0
Identify catchment issues
Catchment scale application The Sankey Now Project n=125
80 60 40 20 0
Management impact n = 125 n = 4569
Sankey Whole Reference Network Significantly/Severely Modified Pristine to Predominantly Unmodified
Determining a Sub-set of Similar Reference Sites
High energy Low energy Low altitude/Low slope High altitude/High slope
30 20 10 0 80 70 60 50 40 Sankey
n = 125
Significantly/Severely Modified Pristine to Predominantly Unmodified
n = 277 n = 4569
Sub-set of reference sites Whole reference Network
Gen. Info: Landuse in the Sankey Catchment Wooded Agricultural Semi-rural Urban
Define strategy tailored to catchment and management needs
Fisheries interest in riffle rehabilitation first choice:
River Weaver
Substrate Analysis of Weaver and Occurrence of Riffles, Compared to National and Regional Mean Averages
Substage Type National Regional Weaver
Bed Rock 3.2
6.6
2.9
Boulders Cobbles 3.8
14.3
8.2
26.9
0.2
8.9
Gravel/Pebble Sand Silt Clay 34.0
5.5
20.3
4.3
22.2
9.6
15.3
0.5
22.9
33.1
21.3
0 No. of Riffles 5.35
4.52
3.91
Criteria Used to Assess Rehabilitation Potential
Rehabilitation Potential Location Map
Stream Power Slope Discharge Width Geomorph. Diversity Erosion Deposition Substrate Flow Types HMI Reinforced, Resectioned Embanked, Berms, Culverts, Art. substrate, Ford, Poaching
Sites with Rehabilitation Potential RHS Sites Potential general rehabilitation Potential rehabilitation for fisheries
Black Brook Site Prior to Rehabilitation
Work in Progress at the Black Brook Site
Test catchment issues
Silt deposition on the Nadder Catchment Erosion Indicators Depositional Features Fine Sediment Source Index
Erosion Indicators (from bank sensitivity index) for RHS Sites on the Nadder Catchment Erosion Indicators
# # # # # # # # # # # # # # # # # # # # # # # # #
Erosion Indicators Existing Potential Historical River Network Nadder Catchment
#
Fig. 21: Depositional Featutes on the Nadder Catchment Depositional Features
# # # # # # # # # # # # # # # # # # # # # # # # # # #
Unvegetated Vegetated River Network Nadder Catchment
#
Fine Sediment Source Index for RHS sites on the Nadder Catchment Fine Sediment Sources
# # # # # # # # # # # # # # # # # # # # # # # # #
Fine Sediment Source Index
#
0 - 32
# #
33 - 60 61 - 90
# #
91 - 122 123 - 160 River Network Nadder Catchment
#
Conclusion Catchment in a stabilising state Potential for erosion Fine sediments from land use run-off
Fisheries Habitats Habitat suitability model for – – – – Salmon and Trout Fry Trout Parr Salmon Parr Salmonid spawning habitat
Suitable Salmonid Habitats
# S # # S
Suitable Salmonid Habitats River Network Nadder Catchment
Barriers to Migration
# # # # # # # # # # # # # # # # # S # # S # # # # # # # # # # # # Major weirs Intermediate weirs
River Network Nadder Catchment
Potential Management Issues Land-use and riparian vegetation River connectivity
Treat problem at source
RHS Contribution to the Mersey Flood Alleviation Scheme 100% Resectioned & bermed, straightened, widened, predominant glide, silty substrate
Removing Fine Sediments From Banks and Berms
Erosion
Predicting species distribution
Distribution of R. Nidd Coarse Fish Communities
Substrate Distribution on the Nidd
Predicted Community Types in Yorkshire Rivers
Developments RHS database 3.2
Water Framework Directive RHS in Europe Educational CDROM Corporate plan: – setting habitat targets for 2002/2003
River Habitat Survey Lead Region Agency Board Chief Executive RHS Project Board Director of Water Management Geoff Mance Head Office Head of Conservation Paul Raven Head Office Meeting twice a year Regional FRCN manager Project Officer David Corbelli LEAP, Queries Promotion Consultants Mark Diamond North West Region Conservation Technical Group Report once a year Budget holder Technical experts Geomorphology, M.Newson, M. Clarke Statistics, J. Jeffers Conservation, N. Holmes RHS Lead Region Team Leader North West Region Technical Expert Jim Walker Geomorphology, Modelling, Queries Marc Naura User Group Meets twice a year RHS experts in each region Comments on developments Scientific Officer Helena Parsons Queries, Training Data analysis, Newsletter
Service Level Agreement Input of data…free of charge!
Queries Methodological advice Database management and training Development of applications Quality Assurance
Quality control Our role – – – 4 levels Visual check at receipt of form Logical checks on all sites and surveyors Random checks on forms + photos Specific checks (site visit, hydrographs) Check on all trainers New surveyors: thorough check of first 10 sites
Future 2004-2006 National survey (4500 sites) Catchment survey for Habitat Quality Targets Catchment survey for Leaps RHS on the Internet