## 2 Materials and Methods
### Database  
#### 2.2.1 Land Cover Reference  
In situ data on the land cover of the test site was acquired during two ground truth campaigns in the summer months of 2010 and 2012. The field work was organized and conducted by Carleton University, (Ottawa, ON, Canada), the NWRC (National Wildlife Research Centre, Ottawa, ON, Canada), and the University of Wuerzburg (Institute of Geography and Geology, Wuerzburg, Germany). Combining the land cover information of our preliminary studies [6; 7; 11; 14], the land cover reference was merged to a common database showing the eight land cover classes listed and described in Table 2. During the field campaigns information on the land cover of representative homogenous locations was recorded, categorized and mapped. The in situ classification of the land cover was completed by field experts, and within the frameworks of [35; 36]. As specified in Table 2 the cut off criteria for the separation of Shrub (ST) and Herb Dominated Tundra (HT) was the presence of dwarf shrubs with a height greater or less than 0.25 m. The separation between Sand (BS) and Mixed Sediment (BM) was based on the presence of pebble, which had to cover \(>\)50% of the surface; the bare ground samples were considered homogeneous if 10% or less were \"other\" materials or vegetation. Locations were classified as Driftwood Accumulation (BW) if more than 80% of the ground were cover by driftwood. Wetland Vegetation Communities (WT) were dominated by grasses, sedges or rushes and frequently occurred inland at creeks and drained lakes. The locations classified as Inundated Low Lying Tundra (WI) exhibited tundra vegetation communities at or near a water body and were most prominent in the low-lying coastal supratidal north of the town of Tuktoyaktuk. Further, Figure 2 provides example photographs of select land cover classes. In total, information from more than fifty ground truth sites were available. Additionally, the number of samples was increased using high resolution airborne imagery with less than one meter spatial resolution provided by [34]. The generation of the land cover reference database was completed and locations of homogenous land cover were digitized using the airborne imagery. The reference information was \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{2}{c}{**Land Cover Class Name**} & \multicolumn{1}{c}{**Description**} & **Abbr.** & **Class Color** \\ \hline \multirow{3}{*}{\begin{tabular}{c} Tundra \\ Vegetation \\ \"T\" \\ \end{tabular} } & Herb & \begin{tabular}{c} upland tundra composed of \\ short herbaceous vegetation \\ and low shrubs (\(<\)25 cm) \\ \end{tabular} & HT & \\  & Dominated Tundra & \begin{tabular}{c} upland tundra dominated by \\ tall shrubs (\(>\)25 cm) \\ \end{tabular} & ST & \\ \hline \multirow{3}{*}{\begin{tabular}{c} Bare Ground \\ \"B\" \\ \end{tabular} } & Shrub & \begin{tabular}{c} upland tundra dominated by \\ (0.625–2.0 mm) \\ \end{tabular} & BS & \\ \cline{2-5}  & & mixed sandy sediment & & \\ \cline{2-5}  & Mixed & \begin{tabular}{c} dominated by gravel, pebble \\ or cobble (2.0–256.0 mm) and \\ without woody debris \\ \end{tabular} & BM & \\ \cline{2-5}  & Driftwood & \begin{tabular}{c} accumulations of driftwood \\ (\(>\)80\%) \\ \end{tabular} & BW & \\ \hline \multirow{3}{*}{\begin{tabular}{c} Wetland \\ \"W\" \\ \end{tabular} } & Wetland & \begin{tabular}{c} wetland vegetation \\ communities dominated by \\ grasses, sedges or rushes \\ \end{tabular} & WT \\ \cline{2-5}  & \begin{tabular}{c} Inundated \\ Low Lying Tundra \\ \end{tabular} & vegetated tundra at or \\ \cline{2-5}  & Water & \
\begin{tabular}{c} Permanent \\ Water Bodies \\ \end{tabular} &
\begin{tabular}{c} ocean, inland lakes, \\ river channels and ponds \\ \end{tabular} & OL \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Land cover classes considered in the analysis; description, class abbreviations (Abbr. ), and class color coding. Bare Ground samples were considered homogeneous if 10% or less were “other” materials or vegetation.