The European part of Russia exhibits highly developed sulphate and carbonate karst. It mostly occurs within river valleys with relatively thin covering deposits. These conditions may induce karst collapses, which appe...The European part of Russia exhibits highly developed sulphate and carbonate karst. It mostly occurs within river valleys with relatively thin covering deposits. These conditions may induce karst collapses, which appear to be the main danger for civil and industrial buildings. Evolution of karst rocks includes several epochs of karst development, which causes complicated distribution of karst caves in karst rocks and, as the result, irregular distribution of karst caves on the surface. Karst hazards prediction is mostly reliable within the geotechnical system “Karst-Construction”, using probability methods. This approach allows creating 3 types of antikarst protection (alternative design of construction arrangement on a plan, structural protection of a construction and plugging of karst caves beneath construction foundation) and selecting the optimum or the most effective version or their rational combination.展开更多
The boom in industrial and infrastructure construction in Saudi Arabia requires in-depth knowledge of the underground conditions to build a sustainable project. This paper gave a practical example of the challenges fa...The boom in industrial and infrastructure construction in Saudi Arabia requires in-depth knowledge of the underground conditions to build a sustainable project. This paper gave a practical example of the challenges facing an existing facility built on a karstic limestone formation in 1970’s. Multiple geophysical techniques such as Microgravity, Electrical Resistivity Imaging, Vertical Seismic Velocity Profiling, Cross Hole Seismic Tomography, Ground Penetration Radar, Multi-Channel Analysis of Surface Waves, as well as boreholes and down-hole video imagery, were deployed through the journey of assessing the karst associated hazards of potential sinkholes or general subsidence. This paper described the karst processes, site geology, geophysical and geotechnical exploration program, and characterizes the subsurface karst conditions at the eastern province of Kingdom of Saudi Arabia. Results and findings of preliminary, geotechnical and geophysical investigations have been utilized to identify the major factors influencing the karst formation. Analyses and integration of obtained results to estimate the type and magnitude of risk affected the major components of industrial facility at the project site using well-known statistical approach were presented in this paper. Consequently number of remedial measures implemented to combating the experienced and expected karst hazards at the studied industrial facility placed in karstified landform are given. A model for using integrated geophysical and geotechnical techniques to assess karst-related risks to a facility was further explored herein.展开更多
In order to study the karstological processes within the karst ecological system,the geohazards and degradation of karst landscapes on the karst areas of the Bakony mountains(Hungary),we investigated the abiotic eleme...In order to study the karstological processes within the karst ecological system,the geohazards and degradation of karst landscapes on the karst areas of the Bakony mountains(Hungary),we investigated the abiotic elements of the environment,soil and cover deposits,erosion soil decay;the changes in the quantity and quality of karst waters:contamination at swallow holes,contamination of karst springs;and the biogenic factors:surface vegetation coverage by the corine land cover method,plant-ecological examinations,qualification of surface waters with the help of biological water labeling.We recognized that the increasing human activities during the past few centuries have had significant impact on the investigated landscapes of karst areas because of their spatial sensitivity.In the scope of our research we concluded that the landscape changes due to natural and human effects can vary strongly on the different karst areas.These differences can arise from the climatic and geomorphologic situation,the coverlayer's qualities,etc.,but primarily from the different utilization of the investigated karst areas(e.g.the intensity,characteristics and territorial extension of utilization).On the spot investigation we detected traces of new and fast geomorphological processes(gully formation,landslides,collapses,new sinkhole development) and landforms(sinkholes,gullies,swallow holes),which are clear evidences of the effect of climatic changes.展开更多
The study of the palaoseismic events in the karst terrains of the Bulgarian Black Sea coast is a very important up-to-date problem. The investigated region is one of the highest-energy regions in Bulgaria with establi...The study of the palaoseismic events in the karst terrains of the Bulgarian Black Sea coast is a very important up-to-date problem. The investigated region is one of the highest-energy regions in Bulgaria with established and recorded catastrophic historic and contemporary earthquakes. The terrain is subjected to the influence not only of its own earthquake foci but also of those in Romania and Russia. The palaeoearthquakes that caused considerable disturbances in the karst terrains along the Northern Bulgarian Black Sea coast have left significant traces. They caused disturbances in the environment and the relief (rearrangement of the surface and ground water karst basins, partially or entirely collapsed caves, deformed caves, oil, gas and salt intrusions and gravitationally formed caves). The ecological consequences in historic and contemporary aspects were catastrophic. The palaeoseismic dislocations were formed as a result of global, regional and local geodynamic events related with the destruction of the Moezian platform and the regional extension of the Black Sea basin. The time of their display and their spatial interrelations were established as a result of complex investigations accompanied by original documents.展开更多
Even though the precipitation is abundant in the Karst region of Guizhou Province, remote villages in this area frequently suffer severe droughts. This paper studied the causes of droughts in this region through field...Even though the precipitation is abundant in the Karst region of Guizhou Province, remote villages in this area frequently suffer severe droughts. This paper studied the causes of droughts in this region through field investigation and references collection. Based on the cause analysis, some suggestions were provided for hazard prevention and control from an engineering perspective. Besides occasional extreme weathers, the drought in this area is primarily caused by its unique geological structures of Karst plateau and underdeveloped agricultural techniques. Meanwhile, the vicious cycle between drought and poverty, which causes the deficiency of water conservancy facilities and hazard prevention awareness, is an important reason for the frequent occurrence of agricultural and socioeconomic drought. Considering the social and economic conditions of remote villages, the long-term control of drought can only be realized if current measures are capable of bring immediate effects and benefits. Therefore, the construction of well-planned and designed water conservancy system based on each village's natural and social conditions are the priority for current hazard prevention. Generally, the exploitation of subterranean river should be considered as the first choice to stabilize the water supply for remote villages. Meanwhile, the construction and improvement of micro water conservancy facilities, such as small water tank, small pond and so on, can effectively support the water providence during droughts as well.展开更多
The Kinta Valley is an area of karst in the north-western part of Peninsular Malaysia. Over 30 years of uncontrolled land use and development has led to significant changes in topography and geomorphology, such as the...The Kinta Valley is an area of karst in the north-western part of Peninsular Malaysia. Over 30 years of uncontrolled land use and development has led to significant changes in topography and geomorphology, such as the appearance of sinkholes. In this paper, geospatial techniques were utilized to the task of evaluating sinkholes susceptibility map using a spatial multi criteria evaluation approach (SMCE). Sinkhole location and a spatial database were applied to calculate eight inherent causative factors for limestone instability namely: lithology, structure (lineament), soil cover, slope, land use mining, urban area features, ponds and rivers. The preparation of the sinkhole geohazard map involved summing the weighted values for each hazard element, which permits the construction of geohazard model;the results of the analysis were validated using the previous actual sinkholes locations in the study area. The spatial distribution of sinkholes occurrence, urban development, faults distribution and ex-mining ponds are factors that are directly responsible for all sinkholes subsidence hazards. Further, the resulting geo-hazard map shows that 93% of recent sinkholes occur in areas where the model flags as “high” and “very high” potential hazard, located in the urbanized part of the valley, while less-developed areas to the west and southwest suffered less sinkhole development. The results can be used for hazard prevention and land-use planning.展开更多
文摘The European part of Russia exhibits highly developed sulphate and carbonate karst. It mostly occurs within river valleys with relatively thin covering deposits. These conditions may induce karst collapses, which appear to be the main danger for civil and industrial buildings. Evolution of karst rocks includes several epochs of karst development, which causes complicated distribution of karst caves in karst rocks and, as the result, irregular distribution of karst caves on the surface. Karst hazards prediction is mostly reliable within the geotechnical system “Karst-Construction”, using probability methods. This approach allows creating 3 types of antikarst protection (alternative design of construction arrangement on a plan, structural protection of a construction and plugging of karst caves beneath construction foundation) and selecting the optimum or the most effective version or their rational combination.
文摘The boom in industrial and infrastructure construction in Saudi Arabia requires in-depth knowledge of the underground conditions to build a sustainable project. This paper gave a practical example of the challenges facing an existing facility built on a karstic limestone formation in 1970’s. Multiple geophysical techniques such as Microgravity, Electrical Resistivity Imaging, Vertical Seismic Velocity Profiling, Cross Hole Seismic Tomography, Ground Penetration Radar, Multi-Channel Analysis of Surface Waves, as well as boreholes and down-hole video imagery, were deployed through the journey of assessing the karst associated hazards of potential sinkholes or general subsidence. This paper described the karst processes, site geology, geophysical and geotechnical exploration program, and characterizes the subsurface karst conditions at the eastern province of Kingdom of Saudi Arabia. Results and findings of preliminary, geotechnical and geophysical investigations have been utilized to identify the major factors influencing the karst formation. Analyses and integration of obtained results to estimate the type and magnitude of risk affected the major components of industrial facility at the project site using well-known statistical approach were presented in this paper. Consequently number of remedial measures implemented to combating the experienced and expected karst hazards at the studied industrial facility placed in karstified landform are given. A model for using integrated geophysical and geotechnical techniques to assess karst-related risks to a facility was further explored herein.
基金This presentation gives an account on the results of the study (OTKA Grant:K 79135)
文摘In order to study the karstological processes within the karst ecological system,the geohazards and degradation of karst landscapes on the karst areas of the Bakony mountains(Hungary),we investigated the abiotic elements of the environment,soil and cover deposits,erosion soil decay;the changes in the quantity and quality of karst waters:contamination at swallow holes,contamination of karst springs;and the biogenic factors:surface vegetation coverage by the corine land cover method,plant-ecological examinations,qualification of surface waters with the help of biological water labeling.We recognized that the increasing human activities during the past few centuries have had significant impact on the investigated landscapes of karst areas because of their spatial sensitivity.In the scope of our research we concluded that the landscape changes due to natural and human effects can vary strongly on the different karst areas.These differences can arise from the climatic and geomorphologic situation,the coverlayer's qualities,etc.,but primarily from the different utilization of the investigated karst areas(e.g.the intensity,characteristics and territorial extension of utilization).On the spot investigation we detected traces of new and fast geomorphological processes(gully formation,landslides,collapses,new sinkhole development) and landforms(sinkholes,gullies,swallow holes),which are clear evidences of the effect of climatic changes.
文摘The study of the palaoseismic events in the karst terrains of the Bulgarian Black Sea coast is a very important up-to-date problem. The investigated region is one of the highest-energy regions in Bulgaria with established and recorded catastrophic historic and contemporary earthquakes. The terrain is subjected to the influence not only of its own earthquake foci but also of those in Romania and Russia. The palaeoearthquakes that caused considerable disturbances in the karst terrains along the Northern Bulgarian Black Sea coast have left significant traces. They caused disturbances in the environment and the relief (rearrangement of the surface and ground water karst basins, partially or entirely collapsed caves, deformed caves, oil, gas and salt intrusions and gravitationally formed caves). The ecological consequences in historic and contemporary aspects were catastrophic. The palaeoseismic dislocations were formed as a result of global, regional and local geodynamic events related with the destruction of the Moezian platform and the regional extension of the Black Sea basin. The time of their display and their spatial interrelations were established as a result of complex investigations accompanied by original documents.
基金supported by the National Natural Science Foundation of China (Grant No.41572285)
文摘Even though the precipitation is abundant in the Karst region of Guizhou Province, remote villages in this area frequently suffer severe droughts. This paper studied the causes of droughts in this region through field investigation and references collection. Based on the cause analysis, some suggestions were provided for hazard prevention and control from an engineering perspective. Besides occasional extreme weathers, the drought in this area is primarily caused by its unique geological structures of Karst plateau and underdeveloped agricultural techniques. Meanwhile, the vicious cycle between drought and poverty, which causes the deficiency of water conservancy facilities and hazard prevention awareness, is an important reason for the frequent occurrence of agricultural and socioeconomic drought. Considering the social and economic conditions of remote villages, the long-term control of drought can only be realized if current measures are capable of bring immediate effects and benefits. Therefore, the construction of well-planned and designed water conservancy system based on each village's natural and social conditions are the priority for current hazard prevention. Generally, the exploitation of subterranean river should be considered as the first choice to stabilize the water supply for remote villages. Meanwhile, the construction and improvement of micro water conservancy facilities, such as small water tank, small pond and so on, can effectively support the water providence during droughts as well.
文摘The Kinta Valley is an area of karst in the north-western part of Peninsular Malaysia. Over 30 years of uncontrolled land use and development has led to significant changes in topography and geomorphology, such as the appearance of sinkholes. In this paper, geospatial techniques were utilized to the task of evaluating sinkholes susceptibility map using a spatial multi criteria evaluation approach (SMCE). Sinkhole location and a spatial database were applied to calculate eight inherent causative factors for limestone instability namely: lithology, structure (lineament), soil cover, slope, land use mining, urban area features, ponds and rivers. The preparation of the sinkhole geohazard map involved summing the weighted values for each hazard element, which permits the construction of geohazard model;the results of the analysis were validated using the previous actual sinkholes locations in the study area. The spatial distribution of sinkholes occurrence, urban development, faults distribution and ex-mining ponds are factors that are directly responsible for all sinkholes subsidence hazards. Further, the resulting geo-hazard map shows that 93% of recent sinkholes occur in areas where the model flags as “high” and “very high” potential hazard, located in the urbanized part of the valley, while less-developed areas to the west and southwest suffered less sinkhole development. The results can be used for hazard prevention and land-use planning.
