Vegetation coverage information extraction of mine dump slope in Wuhai City of Inner Mongolia based on visible vegetation index

ObjectiveThis paper aims to use visible vegetation index to get the slope vegetation coverage of mine dump quickly and accurately, and to provide an effective method for the vegetation investigation of slope in Wuhai mining area, Inner Mongolia of northern China.

MethodThis study selected one of the typical mine dumps in the Wuhai City to choose a suitable visible vegetation index for local research, estimate the dump vegetation coverage, and furthermore try to provide a new method for extracting the dump slope vegetation coverage by means of Quadrat survey, UAV remote sensing and visible vegetation index.

Result(1) Different visible vegetation indexes had varied vegetation extraction effects. Among them, the darker part of red-green ratio index (RGRI) and blue-green ratio index (BGRI) represented the larger vegetation index, while the brighter part of other common visible vegetation indexes represented the larger vegetation index. (2) Gray image feature values of different visible vegetation indexes mainly distributed in range of − 1, 1 in the research area. There was a big overlap of pixel value between vegetation and land in the gray image of normalized green-blue difference index (NGBDI) and BGRI constructed from blue and green bands, which means some partial confusion between them. (3) Visible-band difference vegetation index (VDVI) can extract slope vegetation quickly and accurately among common visible vegetation indices. The average recognition accuracy of VDVI vegetation index was 93.4% by manual visual interpretation and error matrix, showing that VDVI vegetation index could be more suitable for the vegetation extraction on the mine dump in Wuhai City, and was better than the vegetation index of other common visible light. The vegetation coverage of the study area was approximately 20.4% by this method.

ConclusionVisible vegetation index, an unsupervised classified method, could be a new method for investigating vegetation coverage of mine dump slope without selecting reference features by people but extract slope vegetation coverage directly and has a broad application prospect. The study also indicates that VDVI shows higher extraction accuracy of extracting vegetation coverage of mine dump slope in the Wuhai City, which means a practical significance to guide the vegetation restoration in local mine dump.