Active Stage Gully Morphological Characteristics in the Loess iilly-Gully Region Based on 3D Laser Scanning Technique

摘要

Gully erosion plays an important role on sediment production in the Loess Hilly-gully Region. Gully morphology is strongly affected by the gully erosion process and can be used to describe the gully developmental condition. The Chabagou watershed, located in the hilly-gully region of the Loess Plateau, was selected to investigate gully morphological characteristics using a 3D laser scanning technique (LiDAR). We selected 31 representative gullies at active stages, including different watershed locations and gully orders, to quantitatively describe gully morphology and establish empirical equations for estimating gully volume based on gully length and surface area. Images and point clouds datum of the 31 gullies were collected and digital elevation models (DEMs) with 10-cm resolution were generated; then the gully fundamental morphological characteristics including gully length (L), gully width (Wt) and gully depth (D), and some derivative morphological indicators including gully head curvature (C),gully width to depth ratio (w/d), gully bottom to top width ratio (Wb/Wt), gully surface area (Ag) and gully volume (Vg) were extracted from the DEMs using ArcGIS 10.1 (Table 1).