Article
Engineering, Geological
Xiaojun Guo, Yong Li, Xingchang Chen, Ju Zhang, Yuqing Sun
Summary: The study focused on the formation conditions of debris flow/flood in two watersheds in the Wenchuan Earthquake area, China, and found that the runoff and rainfall conditions required for such events increased over time. This increase was attributed to the recovery of vegetation and the reduction of source materials, leading to a higher forecasting efficiency compared to actual monitored flow behaviors and previously proposed rainfall thresholds.
Article
Engineering, Geological
Zhuoyan Jiang, Xuanmei Fan, Srikrishnan Siva Subramanian, Fan Yang, Ran Tang, Qiang Xu, Runqiu Huang
Summary: This study analyzed the evolution of probabilistic rainfall thresholds for post-seismic debris flows using a Bayesian technique, based on triggering and non-triggering rainfall data after the Wenchuan earthquake. The results indicated that antecedent precipitation plays a crucial role in low-intensity long-duration rainfall-induced debris flows, while short-duration high-intensity events are less affected. The study also found that the I-T-D model performed best in investigating uncertainties of rainfall threshold models, providing valuable insights for improving early warning systems for post-seismic debris flows.
ENGINEERING GEOLOGY
(2021)
Article
Engineering, Geological
Fan Yang, Xuanmei Fan, Srikrishnan Siva Subramanian, Xiangyang Dou, Junlin Xiong, Bing Xia, Zongyang Yu, Qiang Xu
Summary: Enhanced debris flow activity has been observed in Sichuan Province, Southwest China after the 2008 Wenchuan earthquake, with intense activity still present more than a decade later. A heavy rainstorm in August 2019 triggered catastrophic debris flows in the epicentral area. Analysis revealed that the 2019 debris flows were mainly initiated by concentrated runoff erosion, differing from previous events.
Article
Geography, Physical
Xiaojun Guo, Peng Cui, Xingchang Chen, Yong Li, Ju Zhang, Yuqing Sun
Summary: This study compared the performance of five hydrological models in simulating peak discharge in small mountainous watersheds, with two models showing good results. The research also found that the ratio of monitored debris flood discharge to simulated water flow discharge decreases after a certain threshold, which may be due to sediment availability reaching a limit in large watersheds.
EARTH SURFACE PROCESSES AND LANDFORMS
(2021)
Article
Engineering, Geological
Fan Yang, Xuanmei Fan, Zhenlei Wei, Srikrishnan Siva Subramanian, Theo W. J. Van Asch, Qiang Xu
Summary: Strong earthquakes can trigger extensive landslides, generating loose deposits that can become debris flows through subsequent rainfall. The parameters controlling post-earthquake debris flow activity and magnitude were poorly understood. This study analyzed debris flows in a representative catchment in the Wenchuan earthquake-hit region from 2008 to 2020, investigating changes in parameters such as material depletion, grain size, and vegetation recovery. The results provide important implications for risk assessment and prediction of future debris flows in earthquake-prone regions.
ENGINEERING GEOLOGY
(2023)
Article
Engineering, Geological
Yan Zhao, Xingmin Meng, Tianjun Qi, Guan Chen, Yajun Li, Dongxia Yue, Feng Qing
Summary: The relationship between rainfall characteristics and debris flow events was analyzed, and a model using machine learning methods was built based on rainfall monitoring records. The results showed that using more rainfall features can improve the accuracy and performance of the prediction model.
Article
Engineering, Environmental
Jiang Xiong, Chuan Tang, Ming Chen, Xianzheng Zhang, Qingyun Shi, Lingfeng Gong
Summary: The article analyzes a catastrophic debris flow event triggered by heavy rainfall in Wenchuan County, China on August 20, 2019, and further discusses the long-term trend of debris flow in the county. The analysis shows that while debris flow activity is decreasing in Wenchuan County, it will still take more than 5 to 10 years to recover to pre-earthquake levels.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Geosciences, Multidisciplinary
Xiaojun Guo, Xingchang Chen, Guohu Song, Jianqi Zhuang, Jianglin Fan
Summary: Debris flows often occur in mountainous watersheds of earthquake-affected areas, with the Lushan earthquake area in southwestern China being a significant hazard. This study found that debris flows are mainly distributed in the northwestern part of the study area, where there is the highest density of active faults. Factors such as rainfall thresholds, temporal variations, and control projects play important roles in triggering and controlling the magnitude of debris flows.
Article
Engineering, Geological
Jian He, Limin Zhang, Ruilin Fan, Shengyang Zhou, Hongyu Luo, Dalei Peng
Summary: This study investigates the effectiveness of mitigation measures against large-scale debris flows in Wenchuan, China. Numerical simulation and field investigations are conducted to evaluate the existing mitigation measures and propose improvements. The study finds that serial check dams can effectively reduce the impact of debris flows, but additional measures may still be necessary in some cases.
Article
Environmental Sciences
Jinn-Chyi Chen, Wen-Shun Huang
Summary: This study investigated the relationship between rainfall return period, probability of debris flow occurrence, and extreme events in the Chenyulan watershed. It presented a model using rainfall indexes to predict the probability of debris flow occurrence, particularly after extreme rainfall events like Typhoon Morakot. The study found that the P-T relationship using the RI or R-d index was reasonable for predicting the probability of debris flow occurrence.
Article
Engineering, Environmental
Ming Chang, Xiangyang Dou, Tristram C. Hales, Bin Yu
Summary: Research in the Wenchuan earthquake region of Southwest China has found that post-earthquake debris flows can be classified into short-term, medium persistent, and long-term intermittent rainfall patterns, each with different characteristics in terms of rainfall intensity, duration, and cumulative rainfall. These patterns have implications for infiltration, saturation, and triggering mechanisms of debris flows. By establishing rainfall-threshold patterns, it is possible to predict the critical initiation conditions of debris flows in different watersheds based on intensity-duration curves.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Engineering, Geological
Wen Zhang, Junqi Chen, Junhua Ma, Chen Cao, Han Yin, Jia Wang, Bo Han
Summary: This study investigates the evolution of sediment and the impact of check dams on it in the Chutou gully during the 2019 and 2020 debris flow. The results show that the sediment evolution remains active in recent years, emphasizing the need for debris flow protection in seismic areas. Check dams play an essential role in protecting against debris flows and significantly influence sediment evolution. It is important to focus on the storage capacity and stability of check dams to prevent subsequent debris flow.
Article
Engineering, Geological
Ni Zhang, Qing Sun
Summary: This study investigated the evolution of coseismic deposits under rainfall and its impact on postseismic debris flows, revealing a multistep evolution process. The volume of postseismic debris flows fluctuated and declined after 20 rainfall events, remaining larger than preseismic debris flows. This research enhances our understanding of the role of coseismic deposits in landscape evolution and postseismic geohazard management.
Article
Geochemistry & Geophysics
Abhey Ram Bansal, Abdolreza Ghods
Summary: The study focused on the dynamic triggering of earthquakes in Iran during 47 recent large earthquakes, finding that triggering often begins during the passage of high amplitude Love waves and continues through the passage of Rayleigh waves. Approximately 10% of the analyzed earthquakes showed evidence of dynamic triggering, which was found to occur in various regions rather than being confined to a small area.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Engineering, Civil
Guo Xiaojun, Cui Peng, Chen Xingchang, Li Yong, Zhang Ju, Sun Yuqing
Summary: Rainfall in mountainous watershed exhibits high spatial variability due to elevation effects, leading to uncertainties in forecasting hydrological hazards like water floods and debris flows. This study investigates the spatial variation of rainfall in a small watershed with 10 rain gauges, establishing a rainfall-elevation relationship based on 52 rainstorm events. Results show lower interpolation errors in areas with high rainfall amounts, while estimating rainfall in high-elevation regions proves more challenging. The study highlights the importance of gauge placement and spacing in accurate rainfall estimation for hazard forecasting.
JOURNAL OF HYDROLOGY
(2021)