Detection of Catchment-Scale Gully-Affected Areas Using Unmanned Aerial Vehicle (UAV) on the Chinese Loess Plateau. - Kai Liu 011; Hu Ding; Guoan Tang; Jiaming Na; Xiaoli Huang; Zhengguang Xue; Xin Yang 005; Fayuan Li (ISPRS Int. J. Geo Inf., 2016)