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71.
Numerical experiments were performed in order to investigate the effects of variations of the transport through the Korea/Tsushima Strait, an inlet of the Japan/East Sea, on the upper layer circulation in the JES based on a 10-month transport observation from May 1999 to March 2000 (Perkins et al., 2000). All external forcings to the model were annual mean fields, except the transport variation through the Korea Strait. In the experiments where the periodic variation of the transport repeated continuously sinusoidally by several periods, strong variability of sea surface height (SSH) was detected in the region extending from the Korea Strait to the Japanese coast due to the geostrophy of the buoyancy forcing at the Korea Strait. The region along the Korean coast is more sensitive to the long-term variations than the short-term (≤60-day period) ones. In two experiments forced by realistic and monthly mean transport, the difference of rms of sea surface height was largest at the Japanese coast and relatively large at the East Korean Warm Current separation region (128∼130°E, 39∼41°N) and to the east of Yamato Rise. The distribution of difference of eddy kinetic energy at 100 m depth between the two experiments was similar to that of the rms of SSH. In the distributions of mean SSH and mean kinetic energy at 100 m depth the realistic transport invokes eddy variability to interact with mean current resulting in the changes of the mean SSH and the mean kinetic energy at the East Korean Warm Current separation region, but it does not produce conspicuous changes in the mean fields of entire JES compared with the mean fields forced by the seasonal transport. 相似文献
72.
Several bathymetric data sets are compared and assessed with constraints of an ocean current model and velocity observations. The root-mean-square (rms) differences among the data sets reach 20 m in the shallow Tsushima/Korea Straits. The numerical experiments to simulate the Tsushima Warm Current are performed using four different topography data sets. The JTOPO1 data (MIRC, 2003) give the smallest rms difference to long-term horizontal velocity observations. Several least-squares combinations of the topography data sets are then sought to minimize the rms difference between the observed and modeled barotropic velocities. Most of the data sets reveal a large bias of 30–60 m at the Western Channel compared to independent sounding depths 相似文献
73.
韩国海岸港口工程概况 总被引:1,自引:0,他引:1
简要介绍了韩国海岸和海洋环境、港口发展、海岸和港口工程的有关机构和团体,并综述其近年来海岸动力方面研究的课题和成果。内容包括海洋动力因素、海岸波浪观测和设计波浪的确定、波浪的传播变形、不规则波理论、非线性波和波浪破碎、波浪与建筑物相互作用、泥沙运动、海岸演变和环境影响分析等方面。 相似文献
74.
《Marine Policy》2015
South Korea's seven governmental ministries and agency jointly announced a “Master Plan for Arctic Policy” on December 10, 2013. This represents the state's first comprehensive Arctic policy document. This paper aims to analyze the Korean government's Master Plan from both the legal and policy perspectives, as well as to make constructive comments for its improvement. Environmental changes, the need for scientific research, growing economic optimism about the Arctic region, and political leadership have led South Korea to head north. These four factors form the basis for the Master Plan. This document outlines Korea's vision (to be a reliable and responsible partner in this polar region), three policy goals, four strategies, and thirty-one projects connected to the Arctic region. The formation of the Master Plan has been an opportunity for South Korea to organize and compile all the various Arctic activities independently conducted by governmental ministries and agency. In order to improve South Korea's Arctic policy since the Master Plan, the author recommends that the nation prioritize its projects according to its needs and the feasibility of each project. Prudence is required in the drafting and implementation of Arctic policy to respect Arctic states' sovereignties and sovereign rights over the Arctic areas. Finally, strengthening cooperation with the Arctic states and at Arctic forums is indispensable. In particular, bilateral cooperation is essential for South Korea to perform economic activities such as the exploration for oil and gas. 相似文献
75.
Myoung?Hak?Oh Ju?Hyung?Lee Gil?Lim?Yoon Junboum?ParkEmail author 《Environmental Geology》2003,45(2):181-189
The grid-net electrical conductivity measurement system for detecting exact locations of landfill leachate intrusion in the subsurface was developed in this study. Laboratory and pilot-scale field model tests were performed to evaluate the direct application of a grid-net electrical conductivity measurement system for the detection of landfill leachate. A significant increase in electrical conductivity of soil was observed by adding landfill leachate. This can be explained as an increase in electrical conductivity of pore fluid due to an increase in leachate constituents as charge carriers. In pilot-scale field model tests, leachate intrusion locations were accurately identified at the initial stage of landfill leachate release by the grid-net electrical conductivity measurement system. The electrical conductivity of the subsurface before leachate injection lay within a small range of 24.8–43.0 S/cm. The electrical conductivity values in detected points were approximately ten times more than the conductivity values of the subsurface without landfill leachate intrusion. The results in this study indicate that the grid-net electrical conductivity measurement method has a possible application for detecting locations of landfill leachate intrusion into the subsurface at the initial stage, and thus has great potential in monitoring leachate leakage at waste landfills. 相似文献
76.
Use of an artificial neural network for analysis of the susceptibility to landslides at Boun,Korea 总被引:13,自引:0,他引:13
Saro?LeeEmail author Joo-Hyung?Ryu Moung-Jin?Lee Joong-Sun?Won 《Environmental Geology》2003,44(7):820-833
The purpose of this study was to develop landslide susceptibility analysis techniques using artificial neural networks and to apply the resulting techniques to the study area of Boun in Korea. Landslide locations were identified in the study area from interpretation of aerial photographs and field survey data. A spatial database of the topography, soil type, timber cover, geology, and land cover was constructed and the landslide-related factors were extracted from the spatial database. Using these factors, the susceptibility to landslides was analyzed by artificial neural network methods. The results of the landslide susceptibility maps were compared and verified using known landslide locations at another area, Yongin, in Korea. A Geographic Information System (GIS) was used to analyze efficiently the vast amount of data and an artificial neural network turned out to be an effective tool to analyze the landslide susceptibility. 相似文献
77.
Origin of Mesozoic gold mineralization in South Korea 总被引:6,自引:0,他引:6
Abstract The Mesozoic gold–silver deposits in South Korea are closely associated with the Mesozoic granitoids. The Jurassic gold–silver deposits can be distinguished from the Cretaceous ones in terms of occurrence, alteration style, gold fineness, associated mineral assemblage, fluid inclusion and stable isotopic compositions. The Jurassic deposits were formed in mesozonal environments related to deep-seated granitoids, whereas the Cretaceous ones were formed in epizonal environments related to shallow-level granitoids. The Jurassic auriferous deposits (about 165–145 Ma) show fluid characteristics typical of an orogenic-type gold deposit, and were probably generated in a compressional regime caused by an orthogonal convergence of the Izanagi oceanic plate into the Asiatic margin. However, strike-slip faults and caldera-related fractures, together with subvolcanic to volcanic activity, may have played an important role in the formation of Cretaceous gold–silver lode deposits (about 110–45 Ma) under a continental arc setting. 相似文献
78.
Hydrochemistry of urban groundwater in Seoul, South Korea: effects of land-use and pollutant recharge 总被引:1,自引:0,他引:1
Byoung-Young Choi Seong-Taek Yun Soon-Young Yu Pyeong-Koo Lee Seong-Sook Park Gi-Tak Chae Bernhard Mayer 《Environmental Geology》2005,48(8):979-990
The ionic and isotopic compositions (δD, δ18O, and 3H) of urban groundwaters have been monitored in Seoul to examine the water quality in relation to land-use. High tritium contents
(6.1–12.0 TU) and the absence of spatial/seasonal change of O–H isotope data indicate that groundwaters are well mixed within
aquifers with recently recharged waters of high contamination susceptibility. Statistical analyses show a spatial variation
of major ions in relation to land-use type. The major ion concentrations tend to increase with anthropogenic contamination,
due to the local pollutants recharge. The TDS concentration appears to be a useful contamination indicator, as it generally
increases by the order of forested green zone (average 151 mg/l), agricultural area, residential area, traffic area, and industrialized
area (average 585 mg/l). With the increased anthropogenic contamination, the groundwater chemistry changes from a Ca–HCO3 type toward a Ca–Cl(+NO3) type. The source and behavior of major ions are discussed and the hydrochemical backgrounds are proposed as the basis of
a groundwater management plan. 相似文献
79.
Sang Joon Pak Seon-Gyu Choi Chang-Whan Oh Chul-Ho Heo Sang-Hoon Choi Sung-Won Kim 《Resource Geology》2006,56(2):117-132
Abstract. The Yuryang gold deposit, comprising a Te‐bearing Au‐Ag vein mineralization, is located in the Cheonan area of the Republic of Korea. The deposit is hosted in Precambrian gneiss and closely related to pegmatite. The mineralized veins display massive quartz textures, with weak alteration adjacent to the veins. The ore mineralization is simple, with a low Ag/Au ratio of 1.5:1, due to the paucity of Ag‐phases. Ore mineralization took place in two different mineral assemblages with paragenetic time; early Fe‐sulfide mineralization and late Fe‐sulfide and Au‐Te mineralization. The early Fe‐sulfide mineralization (pyrite + sphalerite) occurred typically along the vein margins, and the subsequent Au‐Te mineralization is characterized by fracture fillings of galena, sphalerite, pyrrhotite, Te‐bearing minerals (petzite, altaite, hessite and Bi‐Te mineral) and electrum. Fluid inclusions characteristically contain CO2 and can be classified into four types (Ia, Ib, IIa and IIb) according to the phase behavior. The pressure corrected temperatures (≥500d?C) indicate that the deposit was formed at a distinctively high temperature from fluids with moderate to low salinity (<12 wt% equiv. NaCl) and CH4 (1?22 mole %). The sphalerite geo‐barometry yield an estimated pressure about 3.5 ?2.1 kbar. The dominant ore‐deposition mechanisms were CO2 effervescence and concomitant H2S volatilization, which triggered sulfidation and gold mineralization. The measured and calculated isotopic compositions of fluids (δ18OH2O = 10.3 to 12.4 %o; δDH2O = ‐52 to ‐77 %o) may indicate that the gold deposition originated from S‐type magmatic waters. The physicochemical conditions observed in the Yuryang gold deposit indicate that the Jurassic gold deposits in the Cheonan area, including the Yuryang gold deposit are compatible with deposition of the intrusion‐related Au‐Te veins from deeply sourced fluids generated by the late Jurassic Daebo magmatism. 相似文献
80.
Development of a framework of automated water quality parameter optimization and its application 总被引:1,自引:0,他引:1
This paper presents a methodology and framework for the development of an automated least-squares optimization tool for calibrating
water quality parameters in QUAL2E. The method has been applied to estimate the optimal water quality parameters in simulation
of stream water quality for the Anyang stream in Korea. The Monte Carlo analysis is used to assess the relative importance
of model parameters for water quality constituents. It is found that μmax and ρ are the most influential parameters for Chlorophyll-a modeling and K
1 and K
3 are critical parameters for variation of DO and BOD in the Anyang stream. A computer program for automated parameter calibration
has been developed using a nonlinear GRG optimization algorithm. The application framework provides an intuitive and easy-to-use
interface and allows visual evaluation of results. According to the simulation results, the automated approach is computationally
efficient for evaluation of model parameters and converges on a best fit more rapidly and reliably than a trial and error
method. The methodology proposed herein can be extended to other models to obtain the best possible parameter values. 相似文献