Author(s)

XiangHang Bu^1,2*, SongHai Fan^1,2, ZongXi Zhang^1,2, Ke Zhu^1,2, XiaoMin Ma^1,2

Affiliation(s)

¹Electric Power Research Institute of State Grid Sichuan Electric Power Company, Chengdu 610072, Sichuan, China.

²Power Internet of Things Key Laboratory of Sichuan Province, Chengdu 610072, Sichuan, China.

Corresponding Author

XiangHang Bu

ABSTRACT

This paper uses Xiaojiagou in Yingxiu Town as the research object to study the evolution of the material sources in the debris flow basin in the strong earthquake area and predict the characteristics of its washout scale. It does this by using the four-phase high-definition remote sensing imagery and DEM data collected, combining them with ArcGIS technology, to carry out a detailed decipherment of the avalanches and sliders in the basin of Xiaojiagou, and using statistical analysis to derive the evolution law of the material sources and the characteristics of the material sources in the years following the earthquake. The next three to five years will continue to show a decaying trend and finally reach a stable state under the condition of no external force like strong rainfall. According to the field investigation, the ditch still has many channel sources and a small number of landslide sources. Additionally, the ditch's geomorphology makes it more likely that hydrodynamic conditions will form under the downcutting and erosion of earthquakes, flash floods, and debris flows, which in turn causes the initiation of sources and, to some extent, lowers the critical rainfall intensity of debris flow outbreaks. As a result, there is still a chance that debris flows may occur because of persistently heavy rainfall, and early warning, prevention, and control measures must be strengthened. Research on debris flow activity prediction, prevention, and early warning should be intensified. The debris flow in Xiaojiagou would partially silt the river but not completely block it under 5% and 2% rainfall frequency conditions, according to the results of a simulation of the outflow characteristics of the debris flow using the FLO-2D software. Under 1% rainfall frequency conditions, however, the debris flow would completely block the river.

KEYWORDS

Xiaojiagou; Debris flow; Evolution of sources; FLO-2D; Outburst scale

CITE THIS PAPER

XiangHang Bu, SongHai Fan, ZongXi Zhang, Ke Zhu, XiaoMin Ma. Distribution characteristics analyses and trend prediction of geo-hazards in earthquake zones: the case of xiaojiagou watershed in wenchuan earthquake area. Academic Journal of Earth Sciences. 2025, 3(1): 10-18. DOI: https://doi.org/10.61784/ajes3009.

REFERENCES

[1] Dai F, Xu C, Yao X, et al. Spatial distribution of landslides triggered by the 2008 Ms 8.0 Wenchuan earthquake, China. Journal of Asian earth sciences, 2011, 40(4): 883-895.

[2] Cui P, Zhou G G, Zhu X, et al. Scale amplification of natural debris flows caused by cascading landslide dam failures. Geomorphology, 2013, 182: 173-189.

[3] Huo X. Identifying the Characteristics and Implications of Post-Earthquake Debris Flow Events Based on Multi-Source Remote Sensing Images. Remote Sensing, 2024, 16.

[4] Li Ning, Tang Chuan, Bu Xiang, et al. Characteristics and Evolution of Debris Flows in Wenchuan County After "5·12" Earthquake. Journal of Engineering Geology, 2020, 28(6): 1233-1245.

[5] Huang R. Analysis of the after-effects of the Wenchuan Earthquake Geologic Hazard. Journal of Engineering Geology, 2011, 19(2): 145-151.

[6] Tang C, Westen C J V, Tanyas H, et al. Analysing post-earthquake landslide activity using multi-temporal landslide inventories near the epicentral area of the 2008 Wenchuan earthquake. Natural Hazards & Earth System Sciences, 2016, 16(12): 1-26.

[7] Tang D. Numerical simulation study of mudflow with different frequencies based on FLO-2D model. Chengdu University of Technology, 2014.

[8] Liu J, YouYong, Xiaoqing C. Characteristics and hazard prediction of large-scale debris flow of Xiaojia Gully in Yingxiu Town, Sichuan Province, China. Engineering Geology, 2014, 180: 55-67.

[9] Zhang Y, Xiaoqing C, Yong Y, et al. Characteristics of mudflow activities and disaster prevention in Xiaojiagou after Wenchuan earthquake. Soil and Water Conservation Bulletin, 2014, 34(5): 284-289.

[10] Huang R, Li W. Study on the Development and Distribution Laws of Geologic Hazards Triggered by the “5.12” Wenchuan Earthquake. Journal of Rock Mechanics and Engineering, 2008, 27(12): 2585-2592.

[11] Yang T, Tang C, Fang Q, et al. FLO-2D-based simulation study of debris flow of outburst type. Sediment studies, 2017, 42(4): 60-66.

[12] Julien P Y. Physical processes of hyper-concentrated sediment flows. 1985.

[13] Chen M, Luo Y, Tang C, et al. Quantitative assessment of expected direct economic losses of buildings for debris flows in multiple rainfall intensity scenarios in Yangling Gully, Southwest China. Natural Hazards, 2024(3): 120.