Abstract:[Objective] The measurement differences between an unmanned aerial vehicle (UAV) and traditional ground methods were analyzed, and the suitability of extracting the morphological characteristics of erosion gullies by UAV orthophotos in Tibet was studied in order to obtain the parameters of erosion gullies accurately and quickly, with the aim to provide basic information for the prevention and control of gully erosion in the area.[Methods] A total of 20 erosion gullies were selected from 6 research sites, to compare the lengths and widths of erosion gullies measured through field measurements and extraction from UAV orthophotos.[Results] Compared to the results from the field measurements, the mean deviation extent of the erosion gullies' length and width extracted by orthophotos was concentrated between 2%~5% and 0~40%, respectively. Additionally, when the measured width was in the range 400~1 000 cm, the deviation between the extracted and measured values was the lowest. Across the 6 research sites, there was no obvious relationship between the deviation extent of the erosion gullies' morphological parameters extracted by orthophotos and the location. The soil and vegetation near the gully shoulder lines and the grazing damage to the gully shoulder lines were the main factors affecting the extraction of the erosion gullies' morphological characteristics.[Conclusion] UAV remote sensing can provide a convenient and reliable data source for gully erosion monitoring in Tibet.