A Strategic Approach to Managing Mudflat and Saltmarsh Loss across the North Solent, UK.

Flood defence schemes have been delayed across the north Solent because compensatory intertidal habitat could not be secured. The Solent Dynamic Coastal Project was conducted to provide a strategic approach to securing compensatory intertidal habitat to inform the North Solent Shoreline Management Plan.

Intertidal habitat change across the north Solent was estimated to be +50 ha for mudflat and -762 ha for saltmarsh over the next 100 years. Intertidal squeeze requiring compensation, if all existing defences are maintained over the next 100 years, was ∼ 500 – 600 ha. The potential to offset this loss was estimated to be 558 ha (from realignment sites). Sites identified for possible abandonment (686 ha), and hold the line (787 ha), may require further assessment if there is a national shortage of intertidal habitat creation sites and resources are available to fund them. Approximately 407 ha of designated freshwater sites were identified as requiring compensation following realignment or abandonment of defences.

• Introduction

• Method

• Historical aerial photography interpretation (HPI)

• LiDAR and tidal elevation interpretation (LTEI)

• Validation of LiDAR and tidal elevation interpretation (LTEI)

• Historical saltmarsh change

• Predicted future mudflat and saltmarsh change

• Potential habitat creation sites

• Conclusions

• References