Default data: methods and interpretation - A guidance document for 2018 UNCCD

This document complements (i) the reporting manual for the 2017−2018 UNCCD reporting process, which provides information on the use and compilation of the reporting templates; and (ii) the Good Practice Guidance for SDG indicator 15.3.1,1 which describes methods to assess and quantify the proportion of degraded land based on the three land-based indicators. [...] The LC changes were coded following a two-digit system, where the first digit refers to the class of the first year of change and the second digit refers to the class of the second year of change. [...] In the matrix of area changes the rows total (minus the ‘no change’ diagonal value) represents the reductions (losses) and the columns total (minus the ‘no change’ diagonal value) represents the additions (gains) for each of the represented LC classes. [...] integral NDVI over the main seasonal growth cycle in cases of pronounced ecosystem seasonality or integrated yearly NDVI in the absence of pronounced seasonality Calculation of the linear trend of the z-score normalized time series of aggregated NDVI values over the 15 years and parallel calculation of the net change over the same 6 period by applying the Multi Temporal Image Differencing (MTID) m. [...] While LC changes represent the type of change of one LC class to another between an initial and final monitoring year, the LC flows represent the losses and gains of natural land resulting from the processes of change of one LC class to the others and help to identify the degradation status of the land and what changes are considered to be degrading (see Figure 9).