Field testing study on the rainfall thresholds and prone areas of sandstone slope erosion at Mogao Grottoes, Dunhuang
- 35 Downloads
The Dunhuang Mogao Grotto is a famous Buddhist monument and was inscribed in the list of world cultural heritage sites by UNESCO in 1987. Water poses a major threat to the preservation of this heritage even though it is located in an arid region. This study was conducted to investigate the effect of rainfall on rock erosion. Specifically, the formation mechanism of slope runoff and the erosion threshold of rainfall were analyzed, and erosion-prone areas of the site were identified. This was carried out using field artificial rainfall simulation testing, and the results inform methods of preventing rainfall-induced cliff erosion. In addition, the rainfall threshold and erosion-prone areas obtained from the experiment were further validated and optimized using monitoring data for natural rainfall and historic documentation. The threshold value of erosive rainfall obtained by empirical statistical analysis method was found to be similar to that obtained by the runoff generation mechanism. The areas identified as prone to erosion using field tests coincided with areas of historic erosion as recorded in site documentation. Furthermore, the forecast grade of cliff slope erosion and its erosion-prone areas are determined after comprehensive analysis of the results obtained by these two methods. The research results are critical for the monitoring, early warning, and prevention of cliff slope erosion. The research methods can also be used as reference in areas for which rainfall data are missing.
KeywordsSandstone slope Rainfall simulation test Runoff yielding Sediment Rainfall threshold Prone areas
This research was supported by the key research and development plan of Gansu province (No. 17YF1FF104), the major special project of Gansu province (No. 18ZD2FA001), and the project of the Gansu provincial cultural relics bureau (No. 201608; No. 201605).
- Cui, B., Zhang, Y., Xu, X. H., & Wang, Y. (2015). Law of sediment generation and characteristics of eroded sediment on slope vased on simulated rainfall. Soil and Water Conservation in China, 4, 43–45.Google Scholar
- Liu, H. L., Wang, X. D., Zhang, M. Q., Guo, Q. L., Zhang, Z. M., & Wang, Y. W. (2016). Research on the characteristics of rainfall distribution and infiltration in Dunhuang Mogao Grottoes. Science of Conservation and Archaeology, 28(2), 32–37.Google Scholar
- Staley, D. M., Negri, J. A., Kean, J. W., Laber, J. L., Tillery, A. C., & Youberg, A. M. (2016). Prediction of spatially explicit rainfall intensity–duration thresholds for post-fire debris-flow generation in the western United States. Geomorphology, 278, 149–162. https://doi.org/10.1016/j.geomorph.2016.10.019.CrossRefGoogle Scholar
- Zhang, H., Liu, P., Wang, X., Guo, Q., & Zhang, Y. (2009). PS-consolidation of weathered rock at Mogao cliff by perforated pipe grouting technique. Dunhuang Research, 6, 13–20 (in Chinese). https://doi.org/10.13584/j.cnki.issn1000-4106.2009.06.023.CrossRefGoogle Scholar
- Zhu, Y., Cai, Q., Hu, X., & Zhang, G. (2004). Effects of soil physical and chemical properties on soil crusting. Act Pedologica Sinica, 41(1), 13–19.Google Scholar