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Modelling of debris-flow susceptibility and propagation: a case study from Northwest Himalaya
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作者 Hamza DAUD Javed Iqbal TANOLI +5 位作者 Sardar Muhammad ASIF Muhammad QASIM Muhammad ALI Junaid KHAN Zahid Imran BHATTI Ishtiaq Ahmad Khan JADOON 《Journal of Mountain Science》 SCIE CSCD 2024年第1期200-217,共18页
The geological and geographical position of the Northwest Himalayas makes it a vulnerable area for mass movements particularly landslides and debris flows. Mass movements have had a substantial impact on the study are... The geological and geographical position of the Northwest Himalayas makes it a vulnerable area for mass movements particularly landslides and debris flows. Mass movements have had a substantial impact on the study area which is extending along Karakorum Highway(KKH) from Besham to Chilas. Intense seismicity, deep gorges, steep terrain and extreme climatic events trigger multiple mountain hazards along the KKH, among which debris flow is recognized as the most destructive geohazard. This study aims to prepare a field-based debris flow inventory map at a regional scale along a 200 km stretch from Besham to Chilas. A total of 117 debris flows were identified in the field, and subsequently, a point-based debris-flow inventory and catchment delineation were performed through Arc GIS analysis. Regional scale debris flow susceptibility and propagation maps were prepared using Weighted Overlay Method(WOM) and Flow-R technique sequentially. Predisposing factors include slope, slope aspect, elevation, Topographic Roughness Index(TRI), Topographic Wetness Index(TWI), stream buffer, distance to faults, lithology rainfall, curvature, and collapsed material layer. The dataset was randomly divided into training data(75%) and validation data(25%). Results were validated through the Receiver Operator Characteristics(ROC) curve. Results show that Area Under the Curve(AUC) using WOM model is 79.2%. Flow-R propagation of debris flow shows that the 13.15%, 22.94%, and 63.91% areas are very high, high, and low susceptible to debris flow respectively. The propagation predicated by Flow-R validates the naturally occurring debris flow propagation as observed in the field surveys. The output of this research will provide valuable input to the decision makers for the site selection, designing of the prevention system, and for the protection of current infrastructure. 展开更多
关键词 North Pakistan debris flow flow-R Propagation Susceptibility mapping debris-flow inventory Weighted Overlay Method
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Interaction Mechanisms between Natural Debris Flow and Rigid Barrier Deflectors:A New Perspective for Rational Design and Optimal Arrangement
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作者 Yu Huang Beilei Liu +1 位作者 Dianlei Feng Hao Shi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1679-1699,共21页
Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflector... Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further investigation.To date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster prevention.To investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without deflectors.This model was validated using laboratory flume test data from the literature.Then,the model was used to investigate the influence of the deflector angle and multi-barrier arrangements.The optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow mechanisms.The investigation considered the energy dissipation process,retention efficiency,and dead-zone formation.Compared with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris flow.Recommendations for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters. 展开更多
关键词 Rigid barrier deflectors deflector angle single-barrier dual-barrier arrangements viscous debris flow over-spilling delta-plus-SPH
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Debris flow runout behaviors considering the influences of densely populated buildings
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作者 ZHANG Shuai FANG Zhe +4 位作者 DAI Cong WANG Shuairong PENG Jingyu ZHOU Yiling SHEN Ping 《Journal of Mountain Science》 SCIE CSCD 2024年第8期2696-2712,共17页
Debris flows pose serious risks to communities in mountainous areas,often resulting in large losses of human life and property.The impeding presence of urban buildings often affects the runout behavior and deposition ... Debris flows pose serious risks to communities in mountainous areas,often resulting in large losses of human life and property.The impeding presence of urban buildings often affects the runout behavior and deposition of debris flows.But the impact of different building densities and sizes on debris flow dynamics has yet to be quantified to guide urban planning in debris flow risk zones.This study focused on a debris flow that occurred in Zhouqu County,Gansu Province,China on August 7th,2010,which was catastrophic and destroyed many buildings.The FLO-2D software was used to simulate this debris flow in two scenarios,i.e.the presence and the absence of buildings,to obtain debris-flow intensity parameters.The developed model was then used to further analyze the influence of large buildings and narrow channels within the urban environment.The simulation results show that considering the presence of buildings in the simulation is essential for accurate assessment of debris flow intensity and deposition distribution.The layout of buildings in the upstream urban area,such as large buildings or parallel buildings which form narrow channels,can affect the flow velocity and depth of debris flow heading towards downstream buildings.To mitigate damage to downstream buildings,the relative spacing(d/a)between upstream and downstream buildings should not exceed a value of two and should ideally be even lower.These findings provide valuable insights for improving the resistance of mountainous cities to urban debris flows. 展开更多
关键词 debris flow Risk Building blockage effect Zhouqu Urban layout
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Comparison of debris flow susceptibility assessment methods:support vector machine,particle swarm optimization,and feature selection techniques
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作者 ZHAO Haijun WEI Aihua +3 位作者 MA Fengshan DAI Fenggang JIANG Yongbing LI Hui 《Journal of Mountain Science》 SCIE CSCD 2024年第2期397-412,共16页
The selection of important factors in machine learning-based susceptibility assessments is crucial to obtain reliable susceptibility results.In this study,metaheuristic optimization and feature selection techniques we... The selection of important factors in machine learning-based susceptibility assessments is crucial to obtain reliable susceptibility results.In this study,metaheuristic optimization and feature selection techniques were applied to identify the most important input parameters for mapping debris flow susceptibility in the southern mountain area of Chengde City in Hebei Province,China,by using machine learning algorithms.In total,133 historical debris flow records and 16 related factors were selected.The support vector machine(SVM)was first used as the base classifier,and then a hybrid model was introduced by a two-step process.First,the particle swarm optimization(PSO)algorithm was employed to select the SVM model hyperparameters.Second,two feature selection algorithms,namely principal component analysis(PCA)and PSO,were integrated into the PSO-based SVM model,which generated the PCA-PSO-SVM and FS-PSO-SVM models,respectively.Three statistical metrics(accuracy,recall,and specificity)and the area under the receiver operating characteristic curve(AUC)were employed to evaluate and validate the performance of the models.The results indicated that the feature selection-based models exhibited the best performance,followed by the PSO-based SVM and SVM models.Moreover,the performance of the FS-PSO-SVM model was better than that of the PCA-PSO-SVM model,showing the highest AUC,accuracy,recall,and specificity values in both the training and testing processes.It was found that the selection of optimal features is crucial to improving the reliability of debris flow susceptibility assessment results.Moreover,the PSO algorithm was found to be not only an effective tool for hyperparameter optimization,but also a useful feature selection algorithm to improve prediction accuracies of debris flow susceptibility by using machine learning algorithms.The high and very high debris flow susceptibility zone appropriately covers 38.01%of the study area,where debris flow may occur under intensive human activities and heavy rainfall events. 展开更多
关键词 Chengde Feature selection Support vector machine Particle swarm optimization Principal component analysis debris flow susceptibility
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Dynamic-based model for calculating the boulder impact force in debris flow
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作者 YANG Chaoping ZHANG Shaojie +2 位作者 YIN Yueping YANG Hongjuan WEI Fangqiang 《Journal of Mountain Science》 SCIE CSCD 2024年第6期1930-1940,共11页
The boulder impact force in debris flow is generally calculated by static methods such as the cantilever beam models.However,these methods cannot describe the dynamic scenario of boulder collision on structures,so the... The boulder impact force in debris flow is generally calculated by static methods such as the cantilever beam models.However,these methods cannot describe the dynamic scenario of boulder collision on structures,so the inertia and damping effects of the structures are not involved causing an overestimation on the boulder impact force.In order to address this issue,a dynamic-based model for calculating the boulder impact force of a debris flow was proposed in this study,and the dynamic characteristics of a cantilever beam with multiple degrees of freedom under boulder collision were investigated.By using the drop-weight method to simulate boulders within debris flow,seven experiments of drop-weight impacting the cantilever beam were used to calibrate the error of the dynamicbased model.Results indicate that the dynamic-based model is able to reconstruct the impact force history on the cantilever beam during impact time and the error of dynamic-based model is 15.3%in calculating boulder impact force,significantly outperforming the cantilever beam model’s error of 285%.Therefore,the dynamic-based model can overcome the drawbacks of the static-based models and provide a more reliable theoretical foundation for the engineering design of debris flow control structures. 展开更多
关键词 debris flow Impact force Boulder collision Dynamic-based model Engineering design
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Glacial debris flow susceptibility mapping based on combined models in the Parlung Tsangpo Basin,China
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作者 ZHOU Yonghao HU Xiewen +6 位作者 XI Chuanjie WEN Hong CAO Xichao JIN Tao ZHOU Ruichen ZHANG Yu GONG Xueqiang 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1231-1245,共15页
Machine learning(ML)-based prediction models for mapping hazard(e.g.,landslide and debris flow)susceptibility have been widely developed in recent research.However,in some specific areas,ML models have limited applica... Machine learning(ML)-based prediction models for mapping hazard(e.g.,landslide and debris flow)susceptibility have been widely developed in recent research.However,in some specific areas,ML models have limited application because of the uncertainties in identifying negative samples.The Parlung Tsangpo Basin exemplifies a region prone to recurrent glacial debris flows(GDFs)and is characterized by a prominent landform featuring deep gullies.Considering the limitations of the ML model,we developed and compared two combined statistical models(FA-WE and FA-IC)based on factor analysis(FA),weight of evidence(WE),and the information content(IC)method.The final GDF susceptibility maps were generated by selecting 8 most important static factors and considering the influence of precipitation.The results show that the FA-IC model has the best performance.The areas with a very high susceptibility to GDFs are primarily located in the narrow valley section upstream,on both sides of the valley in the middle and downstream of the Parlung Tsangpo River,and in the narrow valley section of each tributary.These areas encompass 86 gullies and are characterized as"narrow and steep". 展开更多
关键词 Parlung Tsangpo Basin Glacial debris flow Factor analysis Susceptibility mapping Weight of evidence Information content method.
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Socio-scientific quantification of the comprehensive benefits of debris flow mitigation measures for villages in western Sichuan, China
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作者 DENG Ting XU Pei +4 位作者 LI Ming LU Yafeng WANG Yukuan LI Zhengyang SHRAVAN Kumar Ghimire 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1598-1612,共15页
Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the speci... Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the specific disasterreduction effects of these measures and their economic,social and ecological benefits is yet to be performed.The western region of Sichuan Province frequentlysuffers from geohazards such as debris flow, and thegovernment has adopted many mitigation measures.This study assessed the benefits of debris flowmitigation measures and identified the key influencingfactors via a field-based study conducted in 81 villagesin western Sichuan province, China. A framework forthe evaluation of the benefits of rural debris flowmitigation measures was constructed andquantitatively evaluated using a survey. Snowballsampling was performed to recruit 81 village leadersand 468 farmers. The results showed that managementand engineering measures were the main methodsused to mitigate debris flow;ecological measures wereauxiliary. The average satisfaction scores of farmers forthese three types of measures were 4.07, 3.90, and 3.56,respectively (as measured on a five-point Likert scale).In contrast, in terms of the benefits of these mitigationmeasures, only a small proportion of villages (11.11%)obtained a high level of comprehensive benefits fromthe debris flow mitigation measures, while the majority(88.89%) received medium to low-level benefits. Toimprove this situation, we further studied and foundthat the main factors that restricted villages fromachieving high-level comprehensive benefits were theunpredictable nature of debris flows, labour forceoutflow and remoteness. Effective control measures, agood economic environment and strong governmentassistance were reported as crucial factors forimproving these comprehensive benefits. This studyprovides socio-scientific references for decisionmakingon rural debris flow mitigation measures while keeping villages at the centre of economic development. 展开更多
关键词 Mitigation measures Comprehensive benefit evaluation debris flow Mountain development Rural areas
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Dynamic response of buildings under debris flow impact
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作者 LIU Huan FAN Xiaoyi +1 位作者 TIAN Shujun DENG Xin 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1581-1597,共17页
This study employs the smoothed particle hydrodynamics–finite element method(SPH–FEM) coupling numerical method to investigate the impact of debris flow on reinforced concrete(RC)-frame buildings. The methodology co... This study employs the smoothed particle hydrodynamics–finite element method(SPH–FEM) coupling numerical method to investigate the impact of debris flow on reinforced concrete(RC)-frame buildings. The methodology considers the variables of debris flow depth and velocity and introduces the intensity index IDV(IDV = DV) to evaluate three different levels of debris flow impact intensity. The primary focus of this study is to investigate the dynamic response and failure mechanism of RC-frame buildings under debris flow impact, including structural failure patterns, impact force and column displacement. The results show that under a highintensity impact, a gradual collapse process of the RCframe building can be observed, and the damage mode of the frame column reflects shear failure or plastic hinge failure mechanism. First, the longitudinal infill walls are damaged owing to their low out-of-plane flexural capacity;the critical failure intensity index IDV value is approximately 7.5 m2/s. The structure cannot withstand debris flows with an intensity index IDV greater than 16 m2/s, and it is recommended that the peak impact force should not exceed 2100 k N. The impact damage ability of debris flow on buildings mostly originates from the impact force of the frontal debris flow, with the impact force of the debris flow body being approximately 42% lower than that of the debris flow head. Finally, a five-level classification system for evaluating the damage status of buildings is proposed based on the numerical simulation and investigation results of the disaster site. 展开更多
关键词 SPH–FEM method debris flow BUILDINGS The intensity index Dynamic response
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Protective effects of baffles with different positions,row spacings,heights on debris flow impact
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作者 SUN Xinpo CHEN Min +5 位作者 BI Yuzhang ZHENG Lu CHE Chi XU Ao TIAN Zijian JIANG Zheyuan 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2352-2367,共16页
The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow movement.Consequently,they are widely used for protection against natural haza... The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow movement.Consequently,they are widely used for protection against natural hazards such as landslides and mudslides.This study,based on the threedimensional DEM(Discrete Element Method),investigated the impact of different baffle positions on debris flow protection.Debris flow velocity and kinetic energy variations were studied through single-factor experiments.Suitable baffle positions were preliminarily selected by analyzing the influence of the first-row baffle position on the impact force and accumulation mass of debris flow.Subsequently,based on the selected baffle positions and four factors influencing the effectiveness of baffle protection(baffle position(P),baffle height(h),row spacing(S_(r)),and angle of transit area(α)),an orthogonal design was employed to further explore the optimal arrangement of baffles.The research results indicate that the use of a baffle structure could effectively slow down the motion velocity of debris flows and dissipate their energy.When the baffle is placed in the transit area,the impact force on the first-row baffle is greater than that when the baffle is placed in the deposition area.Similarly,when the baffle is placed in the transit area,the obstruction effect on debris flow mass is also greater than that when the baffle is placed in the deposition area.Through orthogonal experimental range analysis,when the impact on the first row of baffles is used as the evaluation criterion,the importance of each influencing factor is ranked asα>P>S_(r)>h.When the mass of debris flow behind the baffle is regarded as the evaluation criterion,the rank is changed to P>α>S_(r)>h.The experimental simulation results show that the optimal baffle arrangement is:P_(5),S_(r)=16,α=35°,h=9. 展开更多
关键词 debris flow BAFFLE Protective effect Discrete element
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Analysis of debris flow control effect and hazard assessment in Xinqiao Gully,Wenchuan M_(s)8.0 earthquake area based on numerical simulation
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作者 Chang Yang Yong-bo Tie +3 位作者 Xian-zheng Zhang Yan-feng Zhang Zhi-jie Ning Zong-liang Li 《China Geology》 CAS CSCD 2024年第2期248-263,共16页
Xinqiao Gully is located in the area of the 2008 Wenchuan M_(s)8.0 earthquake in Sichuan province,China.Based on the investigation of the 2023"6-26"Xinqiao Gully debris flow event,this study assessed the eff... Xinqiao Gully is located in the area of the 2008 Wenchuan M_(s)8.0 earthquake in Sichuan province,China.Based on the investigation of the 2023"6-26"Xinqiao Gully debris flow event,this study assessed the effectiveness of the debris flow control project and evaluated the debris flow hazards.Through field investigation and numerical simulation methods,the indicators of flow intensity reduction rate and storage capacity fullness were proposed to quantify the effectiveness of the engineering measures in the debris flow event.The simulation results show that the debris flow control project reduced the flow intensity by41.05%to 64.61%.The storage capacity of the dam decreases gradually from upstream to the mouth of the gully,thus effectively intercepting and controlling the debris flow.By evaluating the debris flow of different recurrence intervals,further measures are recommended for managing debris flow events. 展开更多
关键词 Landslide debris flow Hazard assessment Numerical simulation OpenLISEM Prevention and control project Wenchuan M_(s)8.0 earthquake Xinqiao Gully Sichuan province Geological hazards survey engineering
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Discharge evolution law of debris flow based on a sharp bend physical modeling test
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作者 LU Ming SUN Hao +3 位作者 LIU Jinfeng Abrar HUSSAIN SHANG Yuqi FU Hang 《Journal of Mountain Science》 SCIE CSCD 2024年第6期1904-1915,共12页
For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,th... For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,this study aims to analyze the shear force of debris flows within the bend channel.We established the relationship between the shear force and bend curvature through laboratory experiments.Under the long-term erosion by debris flows,the curvature radius of bends gradually increases,however,when this increasing trend reaches an equilibrium state with the intensity of debris flow discharge,there will be no significant change in curvature radius.In general,the activity pattern and discharges of debris flows would remain relatively stable.Hence,we can infer the magnitude of debris flow discharges from the terrain parameters of the bend channel. 展开更多
关键词 debris flow discharge Erosion effect Bend channel Curvature radius
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Regulation effect of the grille spacing of a funnel-type grating water–sediment separation structure on the debris flow performance
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作者 LI Shuai GU Tianfeng +2 位作者 WANG Jiading WANG Fei LI Pu 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2283-2304,共22页
The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve t... The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve the water–sediment separation ability of the structure.The new funnel-type grating water–sediment separation structure(FGWSS)combines vertical and horizontal structures and provides a satisfactory water–sediment separation effect.However,the regulation effect of the grille spacing of the structure on the debris flow performance has not been studied.The regulation effect of the structure grille spacing on the debris flow performance is studied through a flume test,and the optimal structure grille spacing is obtained.An empirical equation of the relationship between the relative grille spacing of the structure and the sediment separation rate is established.Finally,the influence of the water–sediment separation structure on the regulation effect of debris flows is examined from two aspects:external factors(properties of debris flows)and internal factors(structural factors).The experimental results show that the gradation characteristics of solid particles in debris flows constitute a key factor affecting the regulation effect of the structure on the debris flow performance.The optimum grille spacing of the FGWSS matches the particle size corresponding to the material distribution curves d85~d90 of the debris flow.The total separation rate of debris flow particles is related to the grille spacing of the structure and the content of coarse and fine particles in the debris flow. 展开更多
关键词 debris flow Water–sediment separation structure Grille spacing Performance regulation effect
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Evaluation of the submarine debris-flow hazard risks to planned subsea pipeline systems: a case study in the Qiongdongnan Basin, South China Sea 被引量:1
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作者 Mingquan Huang Xuesheng Qian +1 位作者 Jingping Xu Xuecheng Li 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第5期139-153,共15页
The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a c... The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a case study on evaluating the debris-flow hazard risks to the planned pipeline systems in this region.We used a numerical model to perform simulations to support this quantitative evaluation.First,one relict failure interpreted across the development site was simulated.The back-analysis modeling was used to validate the applicability of the rheological parameters.Then,this model was applied to forecast the runout behaviors of future debris flows originating from the unstable upslope regions considered to be the most critical to the pipeline systems surrounding the Manifolds A and B.The model results showed that the potential debris-flow hazard risks rely on the location of structures and the selection of rheological parameters.For the Manifold B and connected pipeline systems,because of their remote distances away from unstable canyon flanks,the potential debris flows impose few risks.However,the pipeline systems around the Manifold A are exposed to significant hazard risks from future debris flows with selected rheological parameters.These results are beneficial for the design of a more resilient pipeline route in consideration of future debris-flow hazard risks. 展开更多
关键词 submarine debris flow pipeline MANIFOLD hazard evaluation route optimization Qiongdongnan Basin
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Characteristics of debris flow impact on a double-row slit dam 被引量:1
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作者 WANG Zhuang LIU Dao-chuan +6 位作者 YOU Yong LYU Xiao-bo LIU Jin-feng ZHAO Wan-yu SUN Hao WANG Dong-wei LIU Yang 《Journal of Mountain Science》 SCIE CSCD 2023年第2期415-428,共14页
To accurately predict impact loads can ensure the safe operation of debris flow control projects.The instantaneous impact process is usually considered in the calculation of the debris flow impact force;however,the re... To accurately predict impact loads can ensure the safe operation of debris flow control projects.The instantaneous impact process is usually considered in the calculation of the debris flow impact force;however,the redistribution of an impact load after structural regulation is unclear.In this study we deduced the theoretical calculation of a debris flow impact on a double-row slit dam,and carried out a verification experiment on the debris flow impact.The calculation model considers the influence of the debris flow properties,dam arrangement and pile material.The results show that the impact force of the debris flow is obviously affected by the bulk density.When the bulk density is 21 kg/m^(3),the maximum impact force on the pile dam is 1.15 times that when the bulk density is 15 kg/m^(3),but the time it takes for the debris flow to pass through the dam body is reduced by 60%.The larger the relative pile spacing,the more sufficient the flow space and the lower the maximum impact force.The maximum impact force of relative pile spacing of 0.8 is 12%less than that of elative pile spacing of 0.5.The horizontal distribution of the impact force in the mud depth range is parabolic.The maximum impact force on the centre pier is 1.3 times that of a side pier,and the maximum impact force on the dam body appears at the top of the mud depth range.From the vertical distribution of the impact force,the maximum impact force at the highest mud mark is approximately 70%of that of the bottom.With the increase in the relative pile spacing,the longitudinal maximum impact force distribution first decreases and then increases. 展开更多
关键词 debris flow force Slit dam FLUCTUATIONS Flume model test
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Impact of glacier changes and permafrost distribution on debris flows in Badswat and Shishkat catchments,Northern Pakistan
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作者 HASSAN Wajid SU Feng-huan +7 位作者 LIU Wei-ming HASSAN Javed HASSAN Muzammil BAZAI Nazir Ahmed WANG Hao YANG Ze-wen ALI Muzaffar CASTELLANOS Daniel Garcia 《Journal of Mountain Science》 SCIE CSCD 2023年第12期3687-3702,共16页
Knowledge of glacier changes and associated hazards is of great importance for the safety consideration of the population and infrastructure in the mountainous regions of Upper Indus Basin(UIB).In this study,we assess... Knowledge of glacier changes and associated hazards is of great importance for the safety consideration of the population and infrastructure in the mountainous regions of Upper Indus Basin(UIB).In this study,we assessed the variations in glacier velocity,glacier surface elevation change,meteorological conditions,and permafrost distribution in Badswat and Shishkat catchments located in UIB to access the potential impact on the occurrence of debris flow in both catchments.We find that the glacier surface velocity increased during the debris flow event in the Badswat catchment and the mean daily temperature was 3.7℃to 3.9℃higher in most of the locations.The enhanced glacier surface elevation lowering period coincide with the rise in temperature during spring and autumn months between 2015 to 2019 in Badswat catchment.The source region of debris flow falls within the lower boundary of permafrost occurrence zone and lies below the 0℃isotherm during late spring and summer months.In Shishkat catchment the 0℃isotherm reaches above the debris flow source area during August and the glacier do not show any significant variations in velocity and surface elevation change.The debris flow source area is adjacent to the slow-moving rock glacier in Shishkat catchment while in Badswat catchment the debris flow initiated from the former glacier moraine.Both catchments are largely glacierized and thus sensitive to changes in climatic conditions and changes in the cryosphere response possess significant threats to the population downstream.Continuous monitoring of cryosphere-climate change in the region can contribute toward the improvement of disaster risk reduction and mitigation policies. 展开更多
关键词 Cryosphere change Climate change debris flow Remote sensing PERMAFROST Cryosphere hazard
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Morphodynamics and sediment connectivity index in an unmanaged,debris-flow prone catchment:a through time perspective
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作者 Loris TORRESANI Guillaume PITON Vincenzo D’AGOSTINO 《Journal of Mountain Science》 SCIE CSCD 2023年第4期891-910,共20页
Torrential processes are among the main actors responsible for sediment production and mobility in mountain catchments.For this reason,the understanding of preferential pathways for sediment routing has become a prior... Torrential processes are among the main actors responsible for sediment production and mobility in mountain catchments.For this reason,the understanding of preferential pathways for sediment routing has become a priority in hazard assessment and mitigation.In this context,the sediment Connectivity Index(IC)enables to analyse the existing linkage between sediment sources and the selected target(channel network or catchment outlet).The IC is a grid-based index that allows fast computation of sediment connectivity based on landscape information derived from a single Digital Terrain Model(DTM).The index computation is based on the log-ratio between an upslope and a downslope component,including information about drainage area,slope,terrain roughness,and distance to the analysis target(e.g.outlet).The output is a map that highlights the degree of structural connectivity of sediment pathways over analysed catchments.Until now,these maps are however rarely used to help defining debris-flow hazard maps,notably due to a lack of guidelines to interpret the IC spatial distribution.This paper proposes an exploitation procedure along profiles to extract more information from the analysis of mapped IC values.The methodology relies on the analysis of the IC and its component variables along the main channel profile,integrated with information about sediment budgeting derived from Difference of DEMs(DoD).The study of connectivity was applied in the unmanaged sub-catchment(without torrent control works)of the Rio Soial(Autonomous Province of Trento–NE Italy)to understanding the geomorphic evolution of the area after five debris flows(in ten years)and the related changes of sediment connectivity.Using a recent DTM as validation,we demonstrated how an IC analysis over the older DTM can help predicting geomorphic changes and associated hazards.The results show an IC aptitude to capture geomorphic trajectories,anticipate debris flow deposits in a specific channel location,and depict preferential routing pathways. 展开更多
关键词 Sediment Connectivity Index debris flow Hazard assessment Digital Elevation Model Geomorphic evolution DEMs of Difference
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Modeling of breaching parameters for debris flow dams
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作者 RUAN He-chun CHEN Hua-yong +8 位作者 CHEN Xiao-qing ZHAO Wan-yu CHEN Jian-gang WANG Tao JIANG Yao Wang Xi-an Li Xiang-ning LI Xiao YU Yun-han 《Journal of Mountain Science》 SCIE CSCD 2023年第10期2835-2851,共17页
The debris flow dam is a common type of barrier dams,which shows significant differences from other types of barrier dam such as landslide dam,moraine dam in their formation processes,dam body shapes,and internal comp... The debris flow dam is a common type of barrier dams,which shows significant differences from other types of barrier dam such as landslide dam,moraine dam in their formation processes,dam body shapes,and internal compositions.The basic breaching parameters such as flood peak discharge are vital indicators of risk assessment.In this study,we elucidated the failure process of the debris flow dam through the flume experiment,and built the calculation equation of the breaching parameters by selecting critical factors.The result shows that the overtopping failure process of the debris flow dam is capable of forming significantly retrogressive scarps,and the failure process experiences three stages,the formation of the retrogressive scarp,the erosion of the retrogressive scarp,and the decline of the retrogressive scarp.Five factors used for establishing the calculation equations for peak discharge(Qp),final width(Wb)of the breach,and duration(T)of the debris flow dam failure are dam height(h),reservoir capacity(V),the fine grain content(P0.075)of the soil,the nonuniformity coefficient(Cu)of the soil,and the upper limit grain size(D90)of the soil,respectively.In the three equations,the correlation coefficients between Qp,Wb,T and the five factors were 0.86,0.70,0.63,respectively.The equations still need to be modified and verified in actual cases. 展开更多
关键词 debris flow dams Overtopping failure Breaching g parameters Peak discharge Flume experiment
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Impact pressure of debris flow on beam dam
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作者 WANG Dong-wei YOU Yong +2 位作者 LIU Jin-feng SUN Hao WANG Zhuang 《Journal of Mountain Science》 SCIE CSCD 2023年第10期2822-2834,共13页
The use of open-type check dams in mountainous areas has become common practice in order to mitigate the effects of debris flow and extend the service life of engineering structures.The beam dam,a common debris flow c... The use of open-type check dams in mountainous areas has become common practice in order to mitigate the effects of debris flow and extend the service life of engineering structures.The beam dam,a common debris flow control system,has received less attention in research on the impact process of debris flow and check dams compared to solid check dams.Additionally,the estimation of impact pressure in debris flow primarily considers debris flow characteristics,without taking into account the influence of geometric characteristics of the transmission structure.To better understand the impact process of debris flow on beam dams,a series of small-scale debris flow impact tests were conducted in a model flume.Key parameters,including velocity,depth,and impact pressure,were measured.The results show that the maximum impact pressure of debris flow is affected by both the characteristics of the debris flow and the relative opening size of the beam dam.Due to flow and edge occlusion in the middle of the beam dam,the discharge of debris flow is enhanced,resulting in a longer impact process and higher maximum impact pressure.Based on these findings,a calculation model of the maximum impact pressure of debris flow at the midpoint of the middle beam is proposed,which can be used to estimate the impact of debris flow on the discharge part of the beam dam. 展开更多
关键词 debris flow Beam dam Impact pressure Relative opening size Calculation model
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Evaluation of the Economic Loss Caused by Zhouqu Debris Flow 被引量:4
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作者 刘冰 宋玉玲 邓祥征 《Agricultural Science & Technology》 CAS 2012年第5期1081-1085,1132,共6页
[Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the fi... [Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the first time after the disaster, and then built an assessment model to estimate the potential economic losses. [Result] The total loss reached 16.57×10^2 million Yuan, in which indirect economic loss was up to 2.42×10^2 million yaun while the actual direct economic loss was around 14.15×10^2 million Yuan. [Conclusion] The proportional coefficient method is a rapid and efficient method for evaluating the indirect loss caused by disasters. 展开更多
关键词 debris flow Indirect losses Direct losses Proportional coefficient method
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Rainfall Factors in the Prediction of Rainfall-induced Debris Flow
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作者 孙伟 高峰 《Meteorological and Environmental Research》 CAS 2010年第2期76-79,共4页
Various rainfall factors,which affect the activities of rainfall-induced debris flow,are discussed in this paper.The factors include antecedent precipitation,current precipitation,rainfall duration,intensity,peak,and ... Various rainfall factors,which affect the activities of rainfall-induced debris flow,are discussed in this paper.The factors include antecedent precipitation,current precipitation,rainfall duration,intensity,peak,and rainfall pattern.Rainfall-induced debris flow is trigged by the co-action of current rainfall and antecedent rainfall.The advanced system of precipitation monitoring and forecasting in the rainfall-induced debris flow forecast system is established,which consists of four methods-numerical weather prediction,stationary meteorological satellite,weather radar echo and automatic weather station.Since the forecast of rainfall-induced debris flow is based on the prediction of precipitation,the prediction models objectively require more detailed and precise prediction products,which put forward a new research subject for meteorologists. 展开更多
关键词 Rainfall-induced debris flow RAINFALL PRECIPITATION Rainfall intensity China
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