Spatial and temporal variability of soil erosion in the black soil region of Northeast China from 2000 to 2015.

The black soil region in Northeast China is an important production base of commodity grain. However, soil erosion is a major threat that has caused a decline in arable land area and productivity and a series of environmental problems in recent years. To understand the current situation of soil erosion and its changes in the whole black soil region, including six treatment regions, we used the spatial-temporal analysis of soil erosion from 2000 to 2015 and the overlay analysis with its drivers; additionally, soil erosion was evaluated qualitatively with the integrated evaluation method, and its change was indicated by the soil erosion change index (SECI). We found that soil erosion that caused soil loss occurred in each treatment region mainly at the light level in 2015. Water erosion, the most widely distributed erosion type, affected the largest area, while most serious erosion at intensive or higher levels stemmed from wind erosion. Although the situation of water erosion was improved in 2015 compared to that in 2000, the overall situation of soil erosion was worse due to the deterioration of wind and freeze-thaw erosion. Grassland, woodland, and cultivated land changes, such as the conversion from grassland to cultivated land, from woodland to sparse woodland and from dry land to paddy land, revealed these changes to a great extent.