## 3 Results
### Soil Erosion Characteristics of Different Land Use Types  
The majority of land use categories in the study area--more than 72%--are comprised of cropland and woodland. Other land use types make up a smaller proportion (Figure 6). Analyzing the shifts in land use patterns in the forest farming subregion of the Loess Plateau between 2000 and 2020, large changes in cropland land, woodland, waters, and wetland areas have occurred, and the area ratios of woodland and wetland have increased slightly, from 28.91% and 4.22% to 34.34% and 6.88%, respectively. Arable land to water area ratios drastically declined, from 43.33% and 21.95% to 21.95% and 16.07%, respectively, indicating the continued occurrence of the phenomenon of land formation and deforestation around bodies of water (Table 3).  
The state of soil erosion in relation to different forms of land usage (Table 4) shows that more than 87% of the soil erosion in the study area is concentrated in woodland and cropland. This is mostly because the majority of the woods in the research region are situated in terrain with steep hills and mountains, and once the vegetation is destroyed, the vegetation cover decreases rapidly, and large amounts of soil loss can easily occur under heavy rainfall. Although the intensity of soil erosion is generally lower on cropland, the final cumulative result is greater because of the substantial amount of cropland. Grassland and construction land are quite tiny, with an average area share of 1.19% and 0.50% from 2000 to 2020, corresponding to a 20-year average soil erosion of 2131 t/ha per year and 1143 t/ha per year. The major drop in regional erosion in 2010 was mostly caused by an increase in woodland and wetland areas and a marked decrease in other land uses. As a result, the study area's degraded hills should be the focus of soil erosion control efforts, and if appropriate, a mix of engineering, biological, and agricultural approaches should be implemented to restore the degraded hills' ecological health.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **2000** & **2005** & **2010** & **2015** & **2020** \\ \hline Cropland land/(\%) & 43.33 & 42.53 & 40.80 & 40.73 & 41.60 \\ Woodland/(\%) & 28.91 & 30.23 & 32.15 & 32.53 & 34.34 \\ Grassland/(\%) & 1.25 & 1.37 & 0.80 & 0.81 & 0.53 \\ Waters/(\%) & 21.95 & 20.62 & 20.19 & 19.01 & 16.07 \\ Construction Land/(\%) & 0.34 & 0.48 & 0.52 & 0.56 & 0.58 \\ Wetland/(\%) & 4.22 & 4.76 & 5.55 & 6.36 & 6.88 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Statistics of soil erosion intensity in China from 2000 to 2020 land use type area.  
Figure 6: Different land use spatial distributions on the forest farming subregion of Loess Plateau from 2000 to 2020. (**a**) The year 2000; (**b**) the year 2005; (**c**) the year 2010; (**d**) the year 2015; (**e**) the year 2020.  
Combining Tables 3 and 4, it can be noticed that between 2000 and 2020, the area ratio of cropland marginally declined, from 43.33% to 41.60%, corresponding to a decrease in erosion from 4242 t/ha per year to 2160 t/ha per year. On the other hand, the ratio of woodland to construction land increased from 28.91% and 0.34% to 34.34% and 0.58%, and the amount of soil erosion caused by forest area decreased from 4866 t/ha per year to 3787 t/ha per year. As a result, soil erosion improved significantly over this period. Over a period of 20 years, there has been a modification to the local land use pattern, which has effectively reduced soil erosion.