Prewinter soil water regime affects the post-winter cracking position on gully sidewall and slumping soil dynamics in Northeast China

•Soil moisture was manipulated by infiltration at distances from a gully sidewall.•The saturated soil domain was closer to the ground and sidewall under higher infiltration.•Cracks appeared at the upper position of the sidewall after snow melting under higher infiltration.•The slumped soil was greater in spring and less in summer under higher infiltration.•Prewinter soil water affected soil slumping via the freezing and cracking positions.