• Geomechanics and Engineering
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• v.34 no.2
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• pp.155-171
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• 2023

Aiming at the grouting treatment of water inflow in karst conduits, a visualized experiment system for conduit-type grouting blocking was developed. Through the improved water supply system and grouting system, and the optimized multisource information monitoring system, the real-time observation of diffusion and deposition of slurry, and the data acquisition of pressure and velocity during the whole process of grouting were realized, which breaks through the problem that the monitoring element is easy to fail due to slurry adhesion in conventional test system. Based on the grouting experiments in static and flowing water, the diffusion and deposition behavior of the quick-setting slurry under different working conditions were analyzed. The temporal and spatial variation behavior of the pressure and velocity were studied, and the blocking mechanism of the grouting were further revealed. The results showed that: (1) Under the flowing water condition, the counter-flow diffusion distance of slurry was negatively correlated with the flow water velocity and the volume ratio of cement and sodium silicate (C-S ratio), and positively correlated with the grouting volume. The slurry deposition thickness was negatively correlated with the flowing water velocity, and positively correlated with the grouting volume and C-S ratio. (2) The pressure increased slowly before blocking of the flowing water and rapidly after blocking in karst conduits. (3) With the continuous progress of grouting, the flowing water velocity decreased slowly first, then significantly, and finally tended to be stable. According to the research results, some engineering recommendations were put forward for the grouting treatment of the conduit-type water inflow disaster, which has been successfully applied in the treatment project of the China Resources Cement (Pingnan) Limestone Mine. This study provided some guidance and reference for the parameter optimization of grouting for the treatment projects of water inflow in karst conduits.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.75-89
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• 2017

Sinkholes are key karst landforms that primarily evolve through the dissolution of limestone, and it posing a significant threat to roads, buildings, and other man-made structures. This study aims to analyze the area susceptible to sinkhole development using GIS and to identify potential danger area from sinkholes. Eight sinkhole related factors (slope angle, distance to caves, distance to faults, bedrock lithology, soil depth, drainage class, distance to mines, and distance to traffic routes) were constructed as spatial databases with sinkhole inventory. Based on the spatial database, sinkhole susceptibility maps were produced using nearest neighbor distance and frequency ratio models. The maps were verified with prediction rate curve and area under curve. The result indicates that the nearest neighbor distance and frequency ratio models predicted 95.3% and 94.4% of possible sinkhole locations respectively. Furthermore, to identify potential sinkhole danger area, the susceptibility map was compared with population distribution and land use map. It has been found that very highly susceptible areas are along Osipcheon and southeast southwest part of Hajang-myeon and south part of Gagok-myeon of Samcheok-si. Among those areas, it has been identified that potential sinkhole danger areas are Gyo-dong, Seongnae-dong, Jeongna-dong, Namyang-dong and Dogye-eup. These results can be useful in the aspects of land use planning and hazard prevention and management.

• Mycobiology
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• v.49 no.4
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• pp.396-405
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• 2021

Cinnamomum migao plants often face different degrees of drought in karst habitats, which can lead to plants' death, especially in the seedling stage. Widespread of arbuscular mycorrhizal (AM) fungi in karst soils have the potential to address this drought, which is a threat to C. migao seedlings. We inoculated C. migao seedlings with spores from Glomus lamellosum and Glomus etunicatum, two AM fungi widely distributed in karst soils, to observe seedling growth response after simulated drought. Our results showed that 40 g of G. lamellosum and G. etunicatum significantly promoted the growth of C. migao seedlings, 120 days after inoculation. Following a 15-day drought treatment, root colonization of the seedlings with G. lamellosum or G. etunicatum had lower the accumulation of malondialdehyde (MDA) and increased the accumulation of enzymes and osmotic substances in the seedlings. The relative water content in different organs (roots, stems, and leaves) of the drought-stressed seedlings was higher in plants with G. lamellosum or G. etunicatum than in plants without AM fungi colonization. Our results showed that inoculation with AM fungi was an effective means to improve the drought resistance of C. migao seedlings.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.210-224
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• 1996

The SLODSVAT consists of interrelated submodels that simulate : the transfer of radiation, water vapour, sensible heat, carbon dioxide and momentum in two canopy layers determined by environmental conditions and ecophysiological properties of the vegetation ; uptake and storage of water in the "root-stem-leaf" system of plants ; interception of rainfall by the canopy layers and infiltration and storage of rain water in the four soil layers. A comparison of the results of modeling experiments and field micro-climatic observations in a spruce forest(Picea abies [L].Karst) in the Soiling hills(Germany) shows, that the SLODSVAT can describe and simulate the short-term(diurnal) as well as the long-term(seasonal) variability of water vapour and sensible heat fluxes adequately to natural processes under different environmental conditions. It proves that it is possible to estimate and predict the transpiration and evapotranspiration rates for spruce forest ecosystems on the patch and landscape scales for one vegetation period, if certain meteorological, botanical and hydrological information for the structure of the atmospheric boundary layer, the canopy and the soil are available.

• Journal of the Speleological Society of Korea
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• v.55
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• pp.33-44
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• 1998

• Journal of the Speleological Society of Korea
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• no.71
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• pp.19-30
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• 2006

• Journal of the Speleological Society of Korea
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• no.73
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• pp.21-28
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• 2006

• Proceedings of the Speleological Society Conference
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• 1995.09a
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• pp.45-52
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• 1995

카르스트라는 용어는 고대 인도-유럽어로 그 기원은 거슬러 올라간다. 암석을 뜻하는 칼라(Karra)로 부터 그 근원을 찾을 수 있고, 그것의 파생어는 유럽과 중동의 많은 언어에서도 발견된다. 북부의 유고슬라비아에서 그 단어는 칼스(kars)를 거처 카라(Kra)로 발전했다. 또한 유고슬라비아와 이태리의 국경지대인 트라에스트(Trieste)지방에서 그 지역에 대한 지역적인 명칭으로 이것이 '불모의 땅'이라는 뜻이기도 하다. 이 지역은 종종 이 지역의 자연적인 특징이 최초로 광범위하고 과학적인 연구로 받아들여진 지역으로 '고전적인 카르스트'로 언급된다. 로마시대에 지역적인 명칭은 '칼스서 혹은 칼소'(Carsus ＆ Carso)였고, 그것이 오스트리아-헝가리(Austro-Hungarian)제국의 일부분이 되고 나서, '카르스트'(karst)라는 독일말로 정착되어진다. 뷔엔나(Vienna)의 지리학 또는 지질학술대회에서 국제적인 과학적 용어로서 그 단어가 정식으로 사용되었고, 그 용어의 기술적인 사용은 19세기 중반경에 확립되었다.(중략)

• Advances in Traditional Medicine
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• v.10 no.2
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• pp.86-89
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• 2010

Two common Indian spices Carum copticum Karst (ajowan) and Cinnamomum tamala T.Nees. (bay leaves) has been investigated first time to report the activity on the central nervous system. Preliminary study of the hot water extract showed depressant activity on the hole board test as evidenced from the ambulation and head dipping scores. The extracts further quicken the onset and increased the duration of pentobarbital induced sleeping time.

• Animal cells and systems
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• v.16 no.1
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• pp.57-68
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• 2012

Two new harpacticoid species belonging to the genera $Microarthridion$ Lang, 1944 (Tachidiidae) and $Nitocra$ Boeck, 1864 (Ameiridae) are recorded from underground caves in the karst area of Ninh Binh Province, North Vietnam. $Microarthridion$ $thanhi$ n. sp. is distinguished from congeneric species by the number of setae on the antennary exopod, the structure of leg 5 in both sexes, and the finger-like process modified from an outer distal pinnate seta of the third endopodal segment of leg 2 in the male. $Nitocra$ $vietnamensis$ n. sp. has the character combination of six setae on the ellipsoidal exopod of leg 5 in both sexes, the first endopodal segment of leg 1 shorter than the whole exopod, the seta/spine armature of an inner seta of P2-P4 enp-1 and four elements on P2 enp-3, and the reduction of the proximal endite to a seta on the maxillary syncoxa.