1. Morphology Methods for Rivers in the United Kingdom Dr. Chris Bromley Ecology Partnership & Development Unit Scottish Environment Protection Agency

2. Environment Agency (Eng. & Wales) Rules-based screening to identify candidate High Status water bodies. Primarily desk-based approach using expert judgment & some numerical thresholds. National coverage. Accounts for both catchment-wide and within-channel pressures. Damage mostly inferred indirectly. No accounting for channel type or cumulative impacts. Morphological thresholds under development for regulation. For more information please see Niall Jones.

3. Northern Ireland Environment Agency River Hydromorphology Assessment Technique (RHAT). Field & desk-based assessment. Water bodies classified into five classes based on extent of deviation from natural condition. Direct assessment of morphological damage and accounts for cumulative impacts. Based on channel typology (4 classes). Building up to national coverage. Used for RBMP but not for regulation (not dealt with by NIEA). For more information please see Mary Toland.

4. River MImAS River Morphological Impact Assessment System (MImAS) Used for morphology classification, regulation of engineering activities & helping to plan RBMP measures. Expert judgment-based risk assessment tool. Does not provide quantitative assessment of habitat quality. Does not act as an engineering design tool or identify specific restoration measures.

5. Assessing hydromorphological & ecological damage Ecology depends partly on morphology, which can be damaged by physical modifications. Natural ecosystems have the capacity to withstand some modifications. Adverse impacts occur if this capacity is exceeded. The thresholds at which adverse impacts occur have been identified & expressed as a percentage capacity used. River MImAS estimates whether these thresholds have been exceeded.

6. River network Type A Type B Type C Type D Hard bank protection Culvert Bridge No vegetation Simple vegetation Complex continuous vegetation Sensitivity Morphological pressures How MImAS works Type A (bedrock) Type D (actively meandering) HIGH GOOD MODERATE POOR BAD 5% 25% 50% 75%

7. Calculating system capacity % system capacity used per pressure =

8. MImAS for engineering regulation Pressure% Low Impact Channel Realignment19.48 Riparian Vegetation7.80 Pipe and Box Culverts3.36 Bridges1.21 Impoundments0.96 Grey Bank Reinforcement0.10 Green Bank Reinforcement & Bank Reprofiling0.02 Intakes + Outfalls0.02 Total (Moderate Status)32.95 WBID 6209: Kettle Burn; 5.7 km High Impact Channel Realignment 22.3 New total 55.25 Moderate-Poor threshold 50.0 Refuse/modify application

9. MImAS for RBMP Pressure% Low Impact Channel Realignment19.48 Riparian Vegetation7.80 Pipe and Box Culverts3.36 Bridges1.21 Impoundments0.96 Grey Bank Reinforcement0.10 Green Bank Reinforcement & Bank Reprofiling0.02 Intakes + Outfalls0.02 Total (Moderate Status)32.95 WBID 6209: Kettle Burn; 5.7 km Good-Moderate threshold 25.0 Capacity needed to reach Good Status 8.0 Removing Low Impact Realignment frees up 12.5 Total after restoration activity 20.45 Good status attained

10. Summary MImAS provides consistent national assessment of morphological impacts. Transparent & easy to use. Accounts for cumulative impacts, the effect of different scales & different channel types. Calibrated by expert judgement – it’s not a model of complex natural process. Helps us to ask targeted questions about ecosystem functioning. The tool is flexible & easy to update. It will be refined as we: -Develop a better understanding of how morphology and ecology link together. -Gather more data on morphology pressures & channel typology, e.g. from field surveys & licensing activities.