Raw data and analysis for paper 'Use of Surface Motion Characteristics Determined by InSAR to Assess Peatland Condition'

Abstract

Raw and processed ISBAS DInSAR data for 22 sites across the Flow Country NE Scotland corresponding to the paper 'Use of Surface Motion Characteristics Determined by InSAR to Assess Peatland Condition'. Twenty-two study sites each covered by 2 to 6 ISBAS pixels, were selected in the Flow Country, northern Scotland (centered on 58.371478N, 3.658447W), the largest blanket bog in Europe, to cover a spectrum of peatland conditions. The sites are widely dispersed over a 1200 km2 area, range in altitude from 100 to 400m above sea level and have varied hydrological setting and management histories. Two complementary approaches were taken to site selection: 15 sites were chosen to cover a range of average surface motion (in m/year) as had been measured using the ISBAS method over a 21 month period - March 2015 – December 2016 in Alshammari et al. [2018]; 7 sites were chosen on account of having existing detailed field measures of peatland condition. Continuous water level data was available for three of the sites - where it had been recorded every 30 minutes along with water temperature with Orpheus mini data loggers. Supporting this vegetation survey was a cloud-free Sentinel-2 Multispectral Instrument (MSI) image. Of these 22 study sites, 12 study sites were visited over a period of 7 days in the peak of the growing season in 2017. At each of those 12 study sites, 4-6 survey locations were randomly selected. At each survey location, a 10m x 10m square was centered on the GPS coordinate of the spatially coincident Sentinel-2 pixel and the four sides of each square were aligned with the cardinal points, thus in the same orientation as the Sentinel-2 pixels. In each of the 10 x 10m square, the percent cover of key plant functional types (Sphagnum mosses, other mosses, lichen, ericaceous shrubs, sedges, grasses, trees) as well as key features associated with peatland condition and with the potential to influence the spectral signature of the Sentinel-2 data (bare peat, open water and vegetation litter/brash) were noted. For each functional group identified, dominant species were also noted. Each square was photographed from the South-East corner, facing North and vegetation patterns reflecting density and spread of dominant plant functional groups were drawn and annotated for future reference. For each site, general condition was further assessed by noting the presence of drains, tracks, evidence of deer trampling or browsing, presence of natural pools, restoration activity, andestimating distance to road, forestry or infrastructure within a 100m x 100m area around the groups of squares. Land-use history was documented by discussion with land-owners.