Abstract:[Objective]This study aimed to analyze the channel characteristics in a typical small watershed in the black soil region in northeast China,and to explore the methods for distinguishing gullies and stream channels. [Methods]A small watershed(14.59 km2)in the typical black soil region of Bin County,Heilongjiang Province, was selected as the study area. Based on drone imagery and the high-resolution digital elevation model,the Strahler's stream order method was used to classify permanent channels.[Results]The channel density in the watershed was 3.87 km/km2,and the number of channels in the small watershed decreased exponentially as the stream order increased. The proportion of level 1 channels was the highest(64.60%),while the length and area of level 2 channels accounted for the largest proportion,37.62% and 29.57%,respectively. Channels at levels 4 and above had significantly greater width,length,and area than those at lower levels. Channel depth gradually increased from level 4 to level 6. The cross sections of channels at levels 1 to 3 were primarily "V"-shaped or "V"- "U"-shaped. All level 1 to 3 channels were classified as erosion gullies,and level 5 and 6 channels were classified as steam channels,while level 4 channels exhibited characteristics of both.[Conclusion]The Strahler stream order method is applicable for classifying channels in small watersheds of black soil regions. Erosion gullies and stream channels show distinct morphological differences. The findings provide a reference for erosion classification and management.