Saltmarsh Extents And Zonation (EA)

Polygon data layer showing the extent of saltmarsh in England, for use in flood and coastal risk management, and for ecological monitoring and reporting. Saltmarsh extent has been interpreted from aerial imagery (typically 20x20cm resolution), primarily collected between 2006 and 2019. The demarcation of the landward extent is aimed to be the point at which the upper most zones give way to terrestrial plants (often at the foot of a seawall), and where saltmarsh plants become ≤5% of the predominantly terrestrial community. At the seaward end, the final demarcation is aimed to be where the saltmarsh vegetation cover has become so sparse it only represent <5% of the ground cover. Approximately 85% of the national extent has been mapped to zonation level. Zonation classes are the following: Pioneer Spartina Mid-low Upper Marsh Reedbeds Unclassified (saltmarsh; but not classified to zonation level) These zones reflect ecological communities within saltmarsh habitats required for ecological assessment purposes. The mapped extent and zonation has been ground-truthed with data collected by the Environment Agency and Natural England. Aerial imagery used was primarily collected through the Regional Coastal Monitoring Programmes, and other estuarine and coastal strategy monitoring programmes. Limitations and other guidance The dataset does include some, but not all marsh, created at recently breached managed realignment sites. Sites such as Steart Marshes, Salt Fleet Flats Reserve and Allfleet's Marsh have been included. However, other sites such as Medmerry (Sussex coast), Greatham (Tees Estuary) and Hesketh Out Marsh (Ribble Estuary) are yet to be included. It is intended that all such sites will be included in an update to be published in spring 2021. Users should refer to the 'Year' attributes for the timing of image capture, from which extent and zonation mapping has been undertaken. Extent and zonation were typically mapped from the same year of imagery. However, in some instances these years do differ. You can download the dataset HERE. Supporting Documentation