Background Soil and water loss of gully slope in plain sandy area of Jiangsu province is severe. The soil detachment rate and the main controlling factors of gully slope in plain sandy area of Jiangsu province are unclear, which limits the understanding and effective control of erosion in plain sandy area.

Methods Under the conditions of 3 slope gradients (10°, 20° and 30°) and 2 flow rates (0.5 L/s and 1.5 L/s), the soil detachment rate of typical gully slope in 3 types of plain sandy area in Jiangsu province was investigated by variable-slope flume scouring experiments.

Results 1) Soil sand content was high and nutrient was poor of gully slope in plain sandy area of Jiangsu province. The sand content in the plain sandy area of the old Yellow River, the coastal plain sandy area and the high sandy area of Tongnan was 80.64%, 57.24% and 62.22%, respectively. 2) There were significant differences in the average soil detachment rate of gully slope in the three plain sandy areas. The average soil detachment rate was as follows: plain sandy soil area of the old Yellow River (218.0 kg/(m²·s))> coastal plain sandy area (60.9 kg/(m²·s)) > high sandy area of Tongnan (17.1 kg/(m²·s)). 3)The soil detachment rate in the 3 types of plain sandy areas gradually increased with the increasing of slope gradient and flow rate. 4) In soil characteristic factors, soil detachment rate was significantly correlated with water-stable aggregate content, sand content and organic matter content (P < 0.01). In runoff characteristic factors, soil separation rate was significantly positively related to flow power, flow velocity and Reynolds number (P < 0.01).

Conclusions The study clarified the soil detachment rate and its influencing factors of typical gully slope in the three types of plain sandy areas in the Jiangsu Plain at first time. The result of the study may enrich the research theory of gully slope erosion and provide scientific support for gully slope erosion control.