Numerous Quaternary deposits are existed in the mountainous areas of Southwest China,especially in the transition zone between the QinghaiTibet Plateau and the Sichuan Basin,where strong tectonic movements and frequen...Numerous Quaternary deposits are existed in the mountainous areas of Southwest China,especially in the transition zone between the QinghaiTibet Plateau and the Sichuan Basin,where strong tectonic movements and frequent climatic changes increase the potential landslides.The possible deformation and failure process of potential landslides and their impacts on the surrounding environment are important research topics.Field investigation and monitoring indicate that the Qingliu landslide in Xiameng town,Li County,Sichuan Province,China has been continuously deforming since August 2020.The deformation zone has a maximum deformation depth of approximately 18.9m,a total area of 54,628 m2,and a volume of 34.0×104 m3,which seriously threatens infrastructure projects and dwellings.As a result,understanding the Qingliu landslide evolution process,assessing the hazard risk,and planning disaster prevention measures are of great significance for reducing disaster loss.In this study,the mass movement process and hazard risk of the Qingliu landslide are evaluated,and the effects of different prevention measures are compared and discussed.By using the depth-integrated method,the mass movement of the Qingliu landslide is analyzed.The numerical simulation results indicate that the maximum velocity of the Qingliu landslide is approximately 37.5 m/s,and the duration of the landslide is approximately 90s.The simulated landslide can eventually form a deposited mass with a maximum deposit thickness of 19.4 m and an area of approximately 60,168.3 m2,thereby blocking the river and burying dwellings.Furthermore,a risk assessment of the Qingliu landslide under different forms of protection measures is also produced and discussed by considering the hazard level and economic vulnerability level of the affected area.Setting three layers of anti-slide piles on the deformation zone to reduce the hazard risk of the Qingliu landslide is a better choice.Our results may be useful for planning prevention measures and improving disaster emergency response systems.展开更多
The summer resort of Murree and adjoining areas is characterized by high degree of erosivity and erodibility due to both natural and man induced factors. This area is part of a young orogenic belt that is experiencing...The summer resort of Murree and adjoining areas is characterized by high degree of erosivity and erodibility due to both natural and man induced factors. This area is part of a young orogenic belt that is experiencing one of the world’s most rapid uplift rates, and is located in near vicinity of major thrust faults. Shear zones associated with still active faults, such as Murree Thrust and also the folding generated due to thrusting induce an inherited weakness and natural instability potential in the rocks of the Murree Hills. Ever increasing population pressure, deforestation, large\|scale construction works including a new township and a road network have further aggravated the problem. In order to study the landslides and other mass movement related problems in Murree, an area around the main town is selected for detailed analysis of the problem as it has been focus of major development and road construction work. This study is an attempt to prepare a preliminary hazard/landslide map along major road network, around Murree town to identify the unstable areas. Data collection during the fieldwork and its analysis were carried out on Geographic Information System (GIS) based on ILWIS format of the ITC, the Netherlands. Detailed study of a few selected landslides has also been conducted to understand the mechanism of failure and extent of damage.展开更多
High-speed landslide is a catastrophic geological disaster in the mountainous area of southwest China. To predict the movement process of landslide reactivation in Chenjiaba town, Beichuan county, Sichuan province, Ch...High-speed landslide is a catastrophic geological disaster in the mountainous area of southwest China. To predict the movement process of landslide reactivation in Chenjiaba town, Beichuan county, Sichuan province, China, we simulated the movement process of two landslide failures in Chenjiaba via rapid mass movement simulation and unmanned aerial vehicle images(UAV), and obtained the movement characteristic parameters of the landslides. According to a back analysis, the most remarkable fitting rheological parameters were friction coefficient(μ=0.18) and turbulence(). The parameter of landslide pressure was applied as the zoning index of landslide hazard to obtain the influence zone and hazard zoning map of the Chenjiaba landslide. Results show that the Duba River was blocked quickly with a landslide accumulation at the maximum height of 44.14 mwhen the Chenjiaba deposits lost stability. The hazard zoning map indicated that the landslide hazard degree is positively correlated with the slope.This landslide assessment is a quantitative hazard assessment method based on a landslide movement process and is suitable for high-speed landslide. Such method can provide a scientific basis for urban construction and planning in the landslide hazard area to avoid hazards effectively.展开更多
Balia Nala is the outlet of the Nainital lake, flowing towards southeast direction. Presence of Nainital habitation at its right bank has high socio-economic importance. This study presents the stability analysis of a...Balia Nala is the outlet of the Nainital lake, flowing towards southeast direction. Presence of Nainital habitation at its right bank has high socio-economic importance. This study presents the stability analysis of a ravine/valley along Balia Nala. Variegated slates(lower Krol and upper Blaini formations) are the main rock types, wherever the outcrop does exist and rest of the area is covered by slope wash and river borne materials. Three sets of joints are presented in the area, but 4 sets of joints also exist at some locations. Nainital lake fault intersected by Manora fault from southwest direction passes through eastern side of the study area, and some small faults, which are sub-branches of Nainital lake fault, are observed(with 10 m offset) and promote the landslide in the area. This study shows that different kinds of discontinuities(joints, faults and shear zones) and rapid down cutting by the stream due to neotectonic activity affect the stability of the slope. The fragile lithology and deep V-shaped valley further accelerate the mass movement in the study area. In addition, rock mass rating(RMR), factor of safety(FOS) and graphical analysis of the joints indicate the study area as landslide-prone zone. This study will be helpful in not only reducing the risk on life of people, but also in assisting the ongoing civil work in the study area.展开更多
Landslide term is used for all mass movements on slopes, including falling, overturns and flow debris. Using the potential landslide hazard zonation, areas with high potential of landslide hazard can be detected and s...Landslide term is used for all mass movements on slopes, including falling, overturns and flow debris. Using the potential landslide hazard zonation, areas with high potential of landslide hazard can be detected and so prevent the landslide occurrence with providing appropriate solutions. In this study, the landslide hazard zonation along the water transmission lines of the Amir-Almomenin (AS) water supply complex has been done. Studied area is located at the western part of the Northern Khorasan (Bojnord). Study procedure includes the general geology survey, recognition of the most important effective parameters on the landslide phenomena (such as slope, lithology, faults and streams) and has been evaluated as basic maps. Then, each layer was validated based on the importance of the effective factors using the maps weighting method in ArcGis software. Finally, the studied area was zoned based on the landslide potential using the overlapping of the various layers. Final zonation map shows that the North, Northwestern and Median parts of the studied area have the highest landslide potential. These areas are included of Marl and red Marl and to some extend loss deposits with slopes between 14 to more of 50 degrees. Seemingly, faults (due to low occurrence) and streams (due to drought) have lower effect on the landslide potential. However, the degree of the slope and type of lithology are the most important parameters on the landslide potential, respectively.展开更多
Satluj Valley is known to have a history of landslides and related mass movement activities since the geological times. Geological and geomorphological settings combined with anthropogenic activities constitute a prop...Satluj Valley is known to have a history of landslides and related mass movement activities since the geological times. Geological and geomorphological settings combined with anthropogenic activities constitute a propensity towards slope failure. During the last two decades,the area witnessed substantial increase in athropogenic pressure,mainly due to the exploitation of hydropower potential,changing landuse pattern and population growth. In addition,a shift of the climatic patterns in the form of larger area falling under the influence of rains was observed. These natural as well as anthropogenic changes in the area have resulted in increased spatial coverage of landslide in the area. This paper documents these changes during 1990～2006.展开更多
The ro ad n etw o rk in th e H im alayan terrain , connecting re m o te areas e ith e r in th e valleys o r on th e hillslopes, plays a pivotal role in socio-econom ic d e v elo p m en t ofIn d ia. The planning, d ev ...The ro ad n etw o rk in th e H im alayan terrain , connecting re m o te areas e ith e r in th e valleys o r on th e hillslopes, plays a pivotal role in socio-econom ic d e v elo p m en t ofIn d ia. The planning, d ev elo p m en t an d evenm ain ten an ce o f ro ad an d rail netw o rk s in such precarious terrain s are alw ays a challenging task becauseo f com plexities p osed by topography, geological stru ctu res, varied lithology an d neotectonics. Increasingp o p u latio n an d c o n stru ctio n o f roads have led to destab ilisatio n o f slopes, th u s leading to m ass w astingand m ovem ent, fu rth e r aggravation d u e to recen t events o f cloud bu rsts and u n p re c e d e n te d flash floods.V ulnerability analysis o f slopes is an im p o rta n t co m p o n e n t for th e ＂Landslide H azard A ssessm ent＂ and＂Slope Mass C h aracterisation＂ guide p lan n ers to p red ict an d choose suitable w ays for c o n stru ctio n ofroads and o th e r en g in eerin g stru ctu res. The pro b lem o f landslides along th e n ational highw ay-58 （NH-58） from Rishikesh to D evprayag is a co m m o n scene. The slopes along th e NH-58 b e tw e e n Jonk andRishikesh w ere investigated, w h ich experienced v ery heavy traffic especially from M arch to A ugust dueto pilgrim age to K edarnath shrine. On th e basis o f slope m ass rating （SMR） investigation, th e area falls instable class, an d landslide susceptibility score （LSS） values also indicate th a t th e slopes u n d e r investigationfall in low to m o d erate v ulnerability to landslide. More atte n tio n s should be paid to th e slopes toachieve g reater safe an d econom ic b enefits along th e highw ay.展开更多
Mass movement in Sri Lanka is mainly triggered by heavy rainfall. International literature is rich of works defining rainfall intensity-duration models to identify the rainfall threshold for various types of Mass move...Mass movement in Sri Lanka is mainly triggered by heavy rainfall. International literature is rich of works defining rainfall intensity-duration models to identify the rainfall threshold for various types of Mass movement. However, studies have not focused to establish a relationship between intensity and duration of rainfall in Sri Lanka. Therefore, this study focused to establish rainfall intensity-duration models to identify the rainfall threshold for mass movements in Badulla district in Sri Lanka, where forty four (44) rainfall events that resulted in same number of landslides during the last three decades were considered. Results indicate the rainfall threshold relationship fits to the log linear model of the exponential function, I = α·D-β. The constructed I-D curve revealed that short duration (54 mm/h) in rainfall events can potentially trigger the landslide. However, long-duration (>8 h) and low-intensity (<25 mm/h) in rainfall events may also trigger mass movements in Badulla. As per the results, most mass movements occur during northeast monsoons and inter-monsoons. In general, higher mean rainfall intensities trigger the debris flows, while long-duration rainfall events can trigger both landslides and debris flow. When compared to Sri Lankan mass movements triggering threshold intensities are fairly higher than the global threshold values. It confirms that within Badulla, mass movements are triggered by very high intense and/or long duration rainfalls events only. Further, time series analysis of the rainfall events shows an upward trend of extreme rainfall events, which increased landslide occurring frequency in last six (6) years.展开更多
基金the support of the National Natural Science Foundation of China(U2240221,41977229)the Sichuan Youth Science and Technology Innovation Research Team Project(2020JDTD0006)the Sichuan Provincial International Science and Technology Collaboration&Innovation Project(2020YFH0092)。
文摘Numerous Quaternary deposits are existed in the mountainous areas of Southwest China,especially in the transition zone between the QinghaiTibet Plateau and the Sichuan Basin,where strong tectonic movements and frequent climatic changes increase the potential landslides.The possible deformation and failure process of potential landslides and their impacts on the surrounding environment are important research topics.Field investigation and monitoring indicate that the Qingliu landslide in Xiameng town,Li County,Sichuan Province,China has been continuously deforming since August 2020.The deformation zone has a maximum deformation depth of approximately 18.9m,a total area of 54,628 m2,and a volume of 34.0×104 m3,which seriously threatens infrastructure projects and dwellings.As a result,understanding the Qingliu landslide evolution process,assessing the hazard risk,and planning disaster prevention measures are of great significance for reducing disaster loss.In this study,the mass movement process and hazard risk of the Qingliu landslide are evaluated,and the effects of different prevention measures are compared and discussed.By using the depth-integrated method,the mass movement of the Qingliu landslide is analyzed.The numerical simulation results indicate that the maximum velocity of the Qingliu landslide is approximately 37.5 m/s,and the duration of the landslide is approximately 90s.The simulated landslide can eventually form a deposited mass with a maximum deposit thickness of 19.4 m and an area of approximately 60,168.3 m2,thereby blocking the river and burying dwellings.Furthermore,a risk assessment of the Qingliu landslide under different forms of protection measures is also produced and discussed by considering the hazard level and economic vulnerability level of the affected area.Setting three layers of anti-slide piles on the deformation zone to reduce the hazard risk of the Qingliu landslide is a better choice.Our results may be useful for planning prevention measures and improving disaster emergency response systems.
文摘The summer resort of Murree and adjoining areas is characterized by high degree of erosivity and erodibility due to both natural and man induced factors. This area is part of a young orogenic belt that is experiencing one of the world’s most rapid uplift rates, and is located in near vicinity of major thrust faults. Shear zones associated with still active faults, such as Murree Thrust and also the folding generated due to thrusting induce an inherited weakness and natural instability potential in the rocks of the Murree Hills. Ever increasing population pressure, deforestation, large\|scale construction works including a new township and a road network have further aggravated the problem. In order to study the landslides and other mass movement related problems in Murree, an area around the main town is selected for detailed analysis of the problem as it has been focus of major development and road construction work. This study is an attempt to prepare a preliminary hazard/landslide map along major road network, around Murree town to identify the unstable areas. Data collection during the fieldwork and its analysis were carried out on Geographic Information System (GIS) based on ILWIS format of the ITC, the Netherlands. Detailed study of a few selected landslides has also been conducted to understand the mechanism of failure and extent of damage.
基金the support of Institute of Exploration Technology, Chinese Academy of Geological Sciences in helping us conduct the field surveysupported by the Sichuan Youth Science and Technology Foundation (2017JQ0051)+1 种基金the National Natural Science Foundation of China (41371185 and 41401195)the Social Science Research Foundation of Ministry of Education (Engineering and Technology Training Research) (15JDGC019)
文摘High-speed landslide is a catastrophic geological disaster in the mountainous area of southwest China. To predict the movement process of landslide reactivation in Chenjiaba town, Beichuan county, Sichuan province, China, we simulated the movement process of two landslide failures in Chenjiaba via rapid mass movement simulation and unmanned aerial vehicle images(UAV), and obtained the movement characteristic parameters of the landslides. According to a back analysis, the most remarkable fitting rheological parameters were friction coefficient(μ=0.18) and turbulence(). The parameter of landslide pressure was applied as the zoning index of landslide hazard to obtain the influence zone and hazard zoning map of the Chenjiaba landslide. Results show that the Duba River was blocked quickly with a landslide accumulation at the maximum height of 44.14 mwhen the Chenjiaba deposits lost stability. The hazard zoning map indicated that the landslide hazard degree is positively correlated with the slope.This landslide assessment is a quantitative hazard assessment method based on a landslide movement process and is suitable for high-speed landslide. Such method can provide a scientific basis for urban construction and planning in the landslide hazard area to avoid hazards effectively.
文摘Balia Nala is the outlet of the Nainital lake, flowing towards southeast direction. Presence of Nainital habitation at its right bank has high socio-economic importance. This study presents the stability analysis of a ravine/valley along Balia Nala. Variegated slates(lower Krol and upper Blaini formations) are the main rock types, wherever the outcrop does exist and rest of the area is covered by slope wash and river borne materials. Three sets of joints are presented in the area, but 4 sets of joints also exist at some locations. Nainital lake fault intersected by Manora fault from southwest direction passes through eastern side of the study area, and some small faults, which are sub-branches of Nainital lake fault, are observed(with 10 m offset) and promote the landslide in the area. This study shows that different kinds of discontinuities(joints, faults and shear zones) and rapid down cutting by the stream due to neotectonic activity affect the stability of the slope. The fragile lithology and deep V-shaped valley further accelerate the mass movement in the study area. In addition, rock mass rating(RMR), factor of safety(FOS) and graphical analysis of the joints indicate the study area as landslide-prone zone. This study will be helpful in not only reducing the risk on life of people, but also in assisting the ongoing civil work in the study area.
文摘Landslide term is used for all mass movements on slopes, including falling, overturns and flow debris. Using the potential landslide hazard zonation, areas with high potential of landslide hazard can be detected and so prevent the landslide occurrence with providing appropriate solutions. In this study, the landslide hazard zonation along the water transmission lines of the Amir-Almomenin (AS) water supply complex has been done. Studied area is located at the western part of the Northern Khorasan (Bojnord). Study procedure includes the general geology survey, recognition of the most important effective parameters on the landslide phenomena (such as slope, lithology, faults and streams) and has been evaluated as basic maps. Then, each layer was validated based on the importance of the effective factors using the maps weighting method in ArcGis software. Finally, the studied area was zoned based on the landslide potential using the overlapping of the various layers. Final zonation map shows that the North, Northwestern and Median parts of the studied area have the highest landslide potential. These areas are included of Marl and red Marl and to some extend loss deposits with slopes between 14 to more of 50 degrees. Seemingly, faults (due to low occurrence) and streams (due to drought) have lower effect on the landslide potential. However, the degree of the slope and type of lithology are the most important parameters on the landslide potential, respectively.
文摘Satluj Valley is known to have a history of landslides and related mass movement activities since the geological times. Geological and geomorphological settings combined with anthropogenic activities constitute a propensity towards slope failure. During the last two decades,the area witnessed substantial increase in athropogenic pressure,mainly due to the exploitation of hydropower potential,changing landuse pattern and population growth. In addition,a shift of the climatic patterns in the form of larger area falling under the influence of rains was observed. These natural as well as anthropogenic changes in the area have resulted in increased spatial coverage of landslide in the area. This paper documents these changes during 1990～2006.
基金the Chairman of Department of GeologyDepartment of Civil Engineering, Aligarh Muslim University, Aligarh, India for providing necessary facilities to carry out this work
文摘The ro ad n etw o rk in th e H im alayan terrain , connecting re m o te areas e ith e r in th e valleys o r on th e hillslopes, plays a pivotal role in socio-econom ic d e v elo p m en t ofIn d ia. The planning, d ev elo p m en t an d evenm ain ten an ce o f ro ad an d rail netw o rk s in such precarious terrain s are alw ays a challenging task becauseo f com plexities p osed by topography, geological stru ctu res, varied lithology an d neotectonics. Increasingp o p u latio n an d c o n stru ctio n o f roads have led to destab ilisatio n o f slopes, th u s leading to m ass w astingand m ovem ent, fu rth e r aggravation d u e to recen t events o f cloud bu rsts and u n p re c e d e n te d flash floods.V ulnerability analysis o f slopes is an im p o rta n t co m p o n e n t for th e ＂Landslide H azard A ssessm ent＂ and＂Slope Mass C h aracterisation＂ guide p lan n ers to p red ict an d choose suitable w ays for c o n stru ctio n ofroads and o th e r en g in eerin g stru ctu res. The pro b lem o f landslides along th e n ational highw ay-58 （NH-58） from Rishikesh to D evprayag is a co m m o n scene. The slopes along th e NH-58 b e tw e e n Jonk andRishikesh w ere investigated, w h ich experienced v ery heavy traffic especially from M arch to A ugust dueto pilgrim age to K edarnath shrine. On th e basis o f slope m ass rating （SMR） investigation, th e area falls instable class, an d landslide susceptibility score （LSS） values also indicate th a t th e slopes u n d e r investigationfall in low to m o d erate v ulnerability to landslide. More atte n tio n s should be paid to th e slopes toachieve g reater safe an d econom ic b enefits along th e highw ay.
文摘Mass movement in Sri Lanka is mainly triggered by heavy rainfall. International literature is rich of works defining rainfall intensity-duration models to identify the rainfall threshold for various types of Mass movement. However, studies have not focused to establish a relationship between intensity and duration of rainfall in Sri Lanka. Therefore, this study focused to establish rainfall intensity-duration models to identify the rainfall threshold for mass movements in Badulla district in Sri Lanka, where forty four (44) rainfall events that resulted in same number of landslides during the last three decades were considered. Results indicate the rainfall threshold relationship fits to the log linear model of the exponential function, I = α·D-β. The constructed I-D curve revealed that short duration (54 mm/h) in rainfall events can potentially trigger the landslide. However, long-duration (>8 h) and low-intensity (<25 mm/h) in rainfall events may also trigger mass movements in Badulla. As per the results, most mass movements occur during northeast monsoons and inter-monsoons. In general, higher mean rainfall intensities trigger the debris flows, while long-duration rainfall events can trigger both landslides and debris flow. When compared to Sri Lankan mass movements triggering threshold intensities are fairly higher than the global threshold values. It confirms that within Badulla, mass movements are triggered by very high intense and/or long duration rainfalls events only. Further, time series analysis of the rainfall events shows an upward trend of extreme rainfall events, which increased landslide occurring frequency in last six (6) years.
