ISPRS-Archives The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ISPRS-Archives Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci. 2194-9034 Copernicus Publications Göttingen, Germany 10.5194/isprs-archives-XLVI-M-1-2021-441-2021 RESEARCH ON EVALUATION OF THE SPALLING DISEASE OF NICHE FOR BUDDHA IN GROTTOES Miao Y. 1 2 Hou M. 1 2 Wei P. 1 2 School of Geomatics and Urban Spatial Informatics, Beijing University of Civil Engineering and Architecture, No.15 Yongyuan Road, Daxing District, Beijing; 102616, China Beijing Key Laboratory for Architectural Heritage Fine Reconstruction and HealthMonitoring, No.15 Yongyuan Road, Daxing District, Beijing; 102616, China 28 08 2021 XLVI-M-1-2021 441 447 Copyright: © 2021 Y. Miao et al. 2021 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://isprs-archives.copernicus.org/articles/XLVI-M-1-2021/441/2021/isprs-archives-XLVI-M-1-2021-441-2021.html The full text article is available as a PDF file from https://isprs-archives.copernicus.org/articles/XLVI-M-1-2021/441/2021/isprs-archives-XLVI-M-1-2021-441-2021.pdf

The niche for Buddha is an important part of the cultural relics in the grottoes, but it has caused serious spalling disease due to human activities and natural disasters. This paper presents a new quantitative evaluation method for the spalling disease of niche for Buddha. First, the random forest-based method was used to identify the niche for Buddha . Then, the spatial clustering of the head of the niche for Buddha was performed by DBSCAN, and the reference surface was determined by the RANSAC algorithm. Based on this, the spallation depth of the grotto surface was extracted and the relevant index elements were established. The experiment of point cloud data in Cave 18 of Yungang Grottoes proves the rationality of this method, which is of great significance to the protection and virtual restoration of cultural relics in grottoes.