Bank gully extraction from DEMs utilizing the geomorphologic features of a loess hilly area in China

作     者：Xin YANG Jiaming NA Guoan TANG Tingting WANG Axing ZHU 

作者机构：Key Laboratory of Virtual Geographic Environment (Nanjing Normal University)Ministry of EducationNanjing 210023China State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province)Nanjing 210023China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and ApplicationNanjing 210023China Department of GeographyUniversity of Wisconsin-MadisonMadisonWI 53706USA 

出 版 物：《Frontiers of Earth Science》 (地球科学前沿（英文版）)

年 卷 期：2019年第13卷第1期

页      面：151-168页

核心收录：

学科分类：07[理学] 0708[理学-地球物理学] 0704[理学-天文学] 

基　　金：the National Natural Science Foundation of China (Nos.41771415,41471316,and 41271438) a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions No.164320H116. 

主　　题：bank gully DEMs topographic features loess shoulder line relative gully depth 

摘      要：As one of most active gully types in the Chinese Loess Plateau,bank gullies generally indicate soil loss and land degradation.This study addressed the lack of detailed,large scale monitoring of bank gullies and proposed a semi-automatic method for extracting bank gullies,given typical topographic features based on 5 m resolution DEMs.First,channel networks,including bank gullies,are extracted through an iterative channel bum-in algorithm.Second,gully heads are correctly positioned based on the spatial relationship between gully heads and their corresponding gully shoulder lines.Third,bank gullies are distinguished from other gullies using the newly proposed topographic measurement of relative gully depth (RGD).The experimental results from the loess hilly area of the Linjiajian watershed in the Chinese Loess Plateau show that the producer accuracy reaches 87.5%. The accuracy is affected by the DEM resolution and RGD parameters,as well as the accuracy of the gully shoulder line.The application in the Madigou watershed with a high DEM resolution validated the duplicability of this method in other areas.The overall performance shows that bank gullies can be extracted with acceptable accuracy over a large area,which provides essential information for research on soil erosion,geomorphology,and environmental ecology.