4.2. Comparison with global and local studies on soil erosion
estimation
Using RUSLE, the global scale produced annual soil erosion maps (2001
and 2012) at the 25 km spatial resolution were produced and reported by
Borrelli et al. (2017). At the
national scale and seven administrative units of Pakistan;
the globally produced 2012-annual
soil erosion was compared with the 2015-annual soil erosion developed in
the study. For the spatial and statistical comparison, the produced soil
erosion 2015 map was resampled at 25 km. On the national scale as well
as in each administrative unit, the global study reported higher values
and spatial variability as compared to national produced soil erosion
estimations and maps (Table 7 & Figure 9). In few areas of Punjab,
Sindh, Balochistan, and Gilgit-Baltistan, in the global soil erosion
map, no data observed, even where this study reported low (<1
ton/ha/year) annual soil erosion, the global study reported medium (1-5
ton/ha/year) annual soil erosion. For the annual soil erosion, within
Pakistan at the watershed level and basin-scale, using the RUSLE, four
studies over the five sites were reported, which were compared with this
study by comparing mean soil erosion rate (ton/ha/yr) (Figure S1). Over
the Rawal watershed and the Simly watershed we observed the finding of
this study are matching well while in the Ghabbir watershed, Potohar
region and Soan river basin, this study reported very low mean annual
soil erosion values (ton/ha/year) as compared to sub-national scale
studies (Table S5). This might be because of input data sources, spatial
resolutions, variation in factor equations, and study scales.