A strategy for quantifying turbid-water occurrence possibility based on geologic characteristics and soil erosion in hydrologic basins     

Geun-sang Lee  Khil-ha Lee  Gyo-cheol Jeong 《Environmental Earth Sciences》2009,59(4):821-835

Turbid-water problem of reservoirs due to soil erosion causes a major issue in dam operation. This study presents a methodology to quantitatively analyze the occurrence possibility of turbid-water in four hydrologic basins (Sayeon, Degok, Gwangdong, and Imha Dam basins in S. Korea), quantifying the weighting value of turbid-water occurrence in reservoirs. To do this, the study conducted indoor tests, including laser-assisted particle size analysis, X-ray powder diffraction method analysis, and scanning electron microscope, to give the geologic characteristics such as the distribution of soil particle size, settlement time, landslide, and existing sediment yield. The study used RUSLE models to calculate sediment yield on the basis of soil maps, DEMs, and landcover maps as auxiliary data. This study classified factors for evaluating the possibility of turbid-water occurrence into geology, sediment yield, landslide and soil components, and these evaluation items’ weighting and score are presented using the analytic hierarchy process technique. The suggested method is promising in that it can analyze the risk factor of turbid-water occurrence in basins and that can provide a guideline to estimate the turbid-water occurrence of reservoir in dam construction.  相似文献   

DEM matching for bias compensation of rigorous pushbroom sensor models   总被引：1，自引：0，他引：1  

Taejung Kim  Jaehoon Jeong 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(5):692-699

DEM matching is a technique to match two surfaces or two DEMs, at different reference frames. It was originally proposed to replace the need of ground control points for absolute orientation of perspective images. This paper examines DEM matching for precise mapping of pushbroom images without ground control points. We proved that DEM matching based on 3D similarity transformation can be used when model errors are only on the platform’s position and attitude biases. We also proposed how to estimate bias errors and how to update rigorous pushbroom sensor models from DEM matching results. We used a SPOT-5 stereo pair at ground sampling distance of 2.5 m and a reference DEM dataset at grid spacing of 30 m and showed that rigorous pushbroom models with accuracy better than twice of the ground sampling distance both in image and object space have been achieved through DEM matching. We showed further that DEM matching based on 3D similarity transformation may not work for pushbroom images with drift or drift rate errors. We discussed the effects of DEM outliers on DEM matching and automated removal of outliers. The major contribution of this paper is that we validate DEM matching, theoretically and experimentally, for estimating position and attitude biases and for establishing rigorous sensor models for pushbroom images.  相似文献   

Characteristics of landslides induced by a debris flow at different geology with emphasis on clay mineralogy in South Korea     

Gyo-Cheol Jeong  Kyeong-Su Kim  Chang-Oh Choo  Jong-Tae Kim  Man-Il Kim 《Natural Hazards》2011,59(1):347-365

Landslides induced by debris flow have been discussed in relation to the geotechnical properties of soil developed on bedrock, together with an emphasis on the importance of mineralogy comprising precursor soils. Three areas composed of different types of geology were compared to relate landslide with soil compositions: Precambrian gneiss (Jangheung area), Jurassic granite (Sangju area), and Tertiary sedimentary rocks composed of shale and mudstone (Pohang area) in Korea. X-ray diffraction for mineral identification and quantitative analysis, Scanning Electron Microscope for observation of microtexture, and laser size analysis for very fine particles ranging from micrometer were performed, with conventional measurements of particle size, porosity, density, permeability, and consistency for the soils. Soils at landslide sites containing a large amount of finer particles have higher uniformity and gradation coefficients, but lower consistency than those at non-landslide sites. Landslide areas are characterized by higher porosity and lower density. Soil from the gneiss area shows a high plasticity index while that of mudstone has high water content. Main clay minerals contained in soils of the sites where landslides took place are illite, chlorite, kaolinite, and montmorillonite. Mineralogical information on the constituents and microtexture of soils aids in better understanding the causes and patterns of landslide, together with mechanical properties of soils.  相似文献   

Influence on lateral rigidity of offshore piles using proposed p–y curves     

Sangseom Jeong  Youngho Kim  Jaeyoung Kim 《Ocean Engineering》2011,38(2-3):397-408

A fundamental study of pile–soil systems subjected to lateral loads in offshore deposit was conducted using experimental tests and numerical analysis. The emphasis was on the soil–pile rigidity of a laterally loaded pile in marine clay. Rigid- and flexible-pile analyses were conducted for comparison. A framework for determining the lateral load transfer curve (p–y curves) is proposed based on both field and laboratory model tests. A numerical analysis that takes into account the proposed p–y curves was performed for the pile flexibility parameters such as pile diameter, pile length, pile-bending stiffness, and the modulus of subgrade reaction. Based on the analysis, it is shown that the differences in bending moment and lateral displacement are more significant for flexible piles rather than rigid piles. It was found that the p–y curves influence the behavior of flexible piles more than rigid piles, thus the magnitude and distribution of the p–y curves are significantly important in flexible pile design.  相似文献   

Interactions between the pathogenic bacterium <Emphasis Type="Italic">Vibrio parahaemolyticus</Emphasis> and red-tide dinoflagellates     

Kyeong Ah Seong  Hae Jin Jeong 《Ocean Science Journal》2011,46(2):105-115

Vibrio parahaemolyticus is a common pathogenic bacterium in marine and estuarine waters. To investigate interactions between V. parahaemolyticus and co-occurring redtide dinoflagellates, we monitored the daily abundance of 5 common red tide dinoflagellates in laboratory culture; Amphidinium carterae, Cochlodinium ploykrikoides, Gymnodinium impudicum, Prorocentrum micans, and P. minimum. Additionally, we measured the ingestion rate of each dinoflagellate on V. parahaemolyticus as a function of prey concentration. Each of the dinoflagellates responded differently to the abundance of V. parahaemolyticus. The abundances of A. carterae and P. micans were not lowered by V. parahaemolyticus, whereas that of C. polykrikodes was lowered considerably. The harmful effect depended on bacterial concentration and incubation time. Most C. polykrikoides cells died after 1 hour incubation when the V. parahaemolyticus concentration was 1.4×10⁷ cells ml⁻¹, while cells died within 2 days of incubation when the bacterial concentration was 1.5×10⁶ cells ml⁻¹. With increasing V. parahaemolyticus concentration, ingestion rates of P. micans, P. minimum, and A. carterae on the prey increased, whereas that on C. polykrikoides decreased. The maximum or highest ingestion rates of P. micans, P. minimum, and A. carterae on V. parahaemolyticus were 55, 5, and 2 cells alga⁻¹ h⁻¹, respectively. The results of the present study suggest that V. parahaemolyticus can be both the killer and prey for some red tide dinoflagellates.  相似文献   

Determinants of CO2 emission for post-Soviet Union independent countries     

Jeong Hwan Bae  Dmitriy D. Li  Meenakshi Rishi 《Climate Policy》2013,13(5):591-615

This article analyses the determinants of CO₂ emission for 15 post-Soviet Union independent (PSI) countries given their recent transition to market-based economies and their relatively high levels of corruption. The direct and indirect effects of economic growth on CO₂ emission for the PSI countries are derived using a multiple-equation generalized method of moment (GMM) approach to account for simultaneity among corruption, growth and CO₂ emission. A linear relationship between gross domestic product (GDP) and CO₂ emission was observed from the analysis. Furthermore, GDP influences CO₂ emission directly, but also indirectly through its impact on corruption. Similarly, corruption affects CO₂ emission directly, as well as indirectly through its impact on GDP. Political democracy and economic freedom increase CO₂ emission indirectly through their impact on economic growth. Improved energy efficiency and the EU climate policy reduce CO₂ emission, while inflows of foreign direct investment tend to increase CO₂ emission.

Policy relevance

First, PSI countries need to invest more in efficient energy technologies to mitigate CO₂ emission levels significantly. Second, PSI policies aimed at reducing deforestation (thereby increasing population density) may help mitigate carbon emission. Third, PSI countries would be well served to recognize the detrimental effects of foreign direct investment before embarking on a misguided policy path that attracts such inflows at any cost.  相似文献   

Evolution and Sedimentation Mechanisms of Estuarine Beach in the Nakdong River Estuary,Korea: Natural and Human Impact     

Jeong  Joo Bong  Jung  Hoi-Soo  Lee  Jun-Ho  Park  Kyung Kyu  Kim  Seok Yun  Woo  Han Jun 《Ocean Science Journal》2022,57(3):451-466

Ocean Science Journal - Dadae Beach located in the Nakdong River estuary has been continuously evolving as the result of natural and anthropogenetic activities. Due to the geographic...  相似文献   

Rainfall intensity-duration thresholds for landslide prediction in South Korea by considering the effects of antecedent rainfall   总被引：1，自引：0，他引：1  

Moonhyun Hong  Junghwan Kim  Sangseom Jeong 《Landslides》2018,15(3):523-534

This study was conducted to determine the rainfall intensity-duration thresholds (ID curves) for landslide prediction by considering the effects of antecedent rainfall. Data for the time and location of landslides that occurred in South Korea from 1999 to 2016 were collected. Overall, 231 landslide histories from 1999 to 2013 were used to determine the rainfall thresholds, and 12 landslide histories from 2014 to 2016 were used to verify the proposed rainfall thresholds. Probabilistic ID curves were proposed to reflect the influence of other factors except rainfall, and ID curves for various inter-event time definitions (IETDs) were suggested to analyze the variation in the ID curves with the effects of antecedent rainfall. The results suggest that the IETD indicates the duration for which the antecedent rainfall affects the ground condition. It was also found that the ID curve for 12 h of the IETD was the most reliable of the verification procedures using the receiver operating characteristic (ROC) plot and threat score (TS).  相似文献   

Effects of CO2-induced ocean acidification on the growth of the larval olive flounder Paralichthys olivaceus     

Kim  Kyung-Su  Shim  Jeong Hee  Kim  Suam 《Ocean Science Journal》2015,50(2):381-388

It widely thought that ocean acidification processes that caused by atmospheric CO₂ increase and accordingly lower seawater pH conditions might cause serious harm to marine food webs in certain ecosystems in the near future. Little is known about how marine fishes respond to reduced pH conditions. We investigated the effects of CO₂ conditions on the growth of olive flounder (Paralichthys olivaceus) larvae. Newly hatched larvae were reared at three different levels of pCO₂ (574, 988 and 1297 µatm) in temperature-controlled (21 ± 0.5°C) water tanks for four weeks until metamorphosis. The experiment was repeated three times in May, June, and July 2011, and body lengths and weights were measured at the completion of each experiment. The results indicated that the body length and weight of flounder larvae significantly increased with increasing CO₂ concentrations (P < 0.05). A higher daily growth rate during the early larval stage (hatching to 14 days) was found among the larvae reared in low pCO₂ conditions, while a significantly lower growth rate was found among larvae in higher pCO₂ water conditions. On the other hand, in the late larval stage (18 days after hatching to metamorphosis), the daily growth rate of larvae was much higher in high CO₂ water. Bone density of larvae, however, decreased with increasing CO₂ concentration in the water

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First report on the occurrence of the comb pen shell,Atrina pectinata (Linnaeus, 1767) (Bivalvia: Pinnidae) in Ulleungdo Island in the East Sea: Ecology and molecular identification of the species using COI gene sequence     

Hyun-Sung Yang  Hyun-Sil Kang  Heung-Sik Park  Choong Hwan Noh  Eui-Young Jeong  Kwang-Sik Choi 《Ocean Science Journal》2015,50(4):649-655

Pen shell is one of the largest marine bivalves inhabiting shallow subtidal soft bottoms in the west Pacific and Indian Oceans. In Korea, the comb pen shell Atrina pectinata fisheries has been established on the south and west coasts. Recently, a pen shell population has been discovered from a subtidal sand flat (25–30 m depth) in Ulleungdo Island located in the East Sea of Korea, suggesting a potential shellfish resource in this area. In the present study, we first surveyed the population density and size of the unique pen shell using SCUBA, and identified the pen shell to species level using mitochondrial cytochrome oxidase I gene (COI) sequence. An underwater survey carried out from July to September 2013 revealed that populations of pen shell patched on subtidal sand flat at a depth of 20–25 m. Grain size analysis indicated that sand particles accounted for 99% of the 600 × 700 m sand flat. The underwater survey also indicated that density of the pen shell ranged between 6–19 ind/m², with a mean of 11 ind/m². Shell height (i.e. longest axis of the shell) of the pen shell on the sand flat varied between 17.2 cm to 28.8 cm, with a mean of 25.1 cm, and the age was estimated to range between 1.5–7.5 yrs, with a mean of 5 yr. COI DNA sequence obtained from the pen shell in this study showed 98.9–99.2% similarity to Atrina pectinata (Linnaeus 1767) reported from Japan. In the cluster analysis, the COI DNA sequence of the pen shells from Ulleungdo Island was grouped with A. pectinata reported from Japan and China, indicating that the pen shell discovered in this study was A. pectinata, commonly distributed on the west and south coasts of Korea.  相似文献