Assessing the Extent and Severity of Erosion on the Upland Organic Soils of Scotland using Earth Observation: A GIFTSS Implementation Test: Final Report


9. Conclusions

The aim of this study was to build on existing knowledge from research projects on-going in Scotland and the UK on upland peat erosion. A considerable wealth of knowledge already existed into the types and causes of upland peat erosion. There are also studies which have evaluated erosion using different methods ranging from field measurements at set points through to detailed air photo interpretation of rill and gully size and pattern.

Of the main types of peat erosion in the uplands, large single episodic events such as bog bursts and peat slides are the easiest to sense and trace remotely. However these events are infrequent and although of great extent in themselves, have been shown to be less significant than continual local erosion through gulling and rills on blanket bogs at high altitude and shallow slopes. The focus of this work has been on the identification of these gullies and rills through the application of EO.

EO, and in particular the combination of airborne and spaceborne imagery, provides the opportunity for a consistent, objective mapping, from a selection of sensors over a range of mapping scales.

Following assessment, an approach utilising an object orientated rule based classification was chosen as it permits knowledge of both the ecology and the content within the EO data to be incorporated into the classification process. The results from both Phase 1 and 2 show that using a combination of very high resolution aerial photography, with high and very high resolution multispectral satellite imagery it is possible to integrate these with knowledge of the landscape processes to extract erosion features at the appropriate fine scale.

Success of the project came from not simply considering this as an ecological project, or as a remote sensing project. Rather the success came from coupling ecological knowledge, with remote sensing expertise and EO information content. The combination of this skill set cannot be underestimated.

The traditional presentation of EO accuracy information has been questioned and proposals have been made that there is a need to move away from the concept of crisp Boolean mapping to one based on upper and lower bounds of belief; to try to manage and represent the variation and uncertainty on the ground ( e.g., mixed pixels, mosaics, etc). Particularly given promotion of deeper non-expert access to spatial data and environmental decision making through a range of initiatives.

During the Phase 2 work, consideration has been given to a possible future classification (in particular the rule-based approach) across Scotland and the successful transfer of rules established in one area to another.

It is proposed that the Scottish Government should adopt the use of EO for mapping and monitoring peat erosion across Scotland. Initially through a short project to confirm the transferability of the approach to a second area of Scotland. This could take the form of a 'rapid implementation' to assess and confirm the biogeographical effect on the process. A project of this nature would also provide an additional short term output for the Scottish Government, including further examination of additional 'application levels' that could usefully be generated from the ''core levels' in support of policy delivery, whilst full funding is being considered.