Background A field survey of gully erosion in a typical black soil region was conducted to verify the results from remote sensing interpretation announced by Chinese government in 2013, aiming to provide a scientific basis for the evaluation and prevention of gully erosion in the black soil region of Northeast China.

Methods A rolling hilly region of 450 km² with severe gully erosion was selected as the field survey area of this study. The land use, geographic coordinates and morphological parameters of gullies were measured to be compared and analyzed with the results of the national census announcement in this study region.

Results The remote sensing interpretation only focused on the gullies with length of 100-5 000 m. Our results showed that the gully number (1 044) obtained by field survey including the gullies of < 100 m in length (235) and main gully channels (13) was nearly double that (574) from remote sensing interpretation, indicating the accuracy rate of the number of gullies confirmed by remote sensing interpretation was 72.1% in the survey area. The gully density obtained by remote sensing interpretation was 0.78 km/km² that was close to half of that (1.2 km/km²) by field survey. The gully area by remote sensing interpretation and field survey was 1.44% and 2.45%, respectively, implying that the remote sensing interpretation underestimated the gully intensity by one class according to the national classification standard of gully erosion intensity. The lower quantity of different types of gullies obtained by remote sensing interpretation than field survey was mainly due to the low-resolution DEM and the difficulty of obtaining some gully information from satellite images. The gully volume had the optimal relation with gully area (R²=0.936).

Conculsions Overall, both number of gullies and intensity of gully erosion in the survey area are higher than the results announced by government in 2013. The most gullies are small and medium-sized gullies developed in cultivated lands, which are mostly in the development stage and are relatively easy to manage.