• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1076-1080
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• 2007

최근 국내에서는 하천변 생태계를 대상으로 생태구조 및 서식처 평가 등 많은 연구가 진행되었음에도 불구하고 생태적 변화를 예측하고 예측된 결과에 따라 생태복원 대책을 수립할 수 있는 연구는 현재까지 미흡하다고 볼 수 있으며, 이는 생태복원 연구에 있어 주요과제라고 할 수 있다. 이에 반해 유럽과 미국에서는 수문학적 서식처 조건에 따른 식생 반응 예측 등 수문생태 모형에 대한 연구가 꾸준히 이루어져 왔으며, 최근에는 습지, 홍수터 등을 대상으로 생태보전 복원분야에 널리 응용되고 있다. 본 연구에서는 국외의 수문생태모형 적용사례를 분석하여 국내 적용가능성 및 문제점에 대한 타당성을 제시하고자 하였다. 그 대상으로는 유역 내에 홍수량 분담을 위한 천변저류지를 적용하였으며, 의미상으로 홍수터(범람원), 습지 역시 해당 범위에 포함할 수 있다. 천변저류지는 홍수기와 비홍수기에 따라 활용 측면을 구분할 수 있으며, 이런 맥락에서 천변저류지의 수위변화는 식생 변화의 중요한 요소(factor)가 될 수 있다. 그 외 범람시기, 범람일수, 건조기간 등을 포함한 수문요소 역시 수문생태 모델의 예측 변수인 식생 성장에 영향을 미치게 된다. 이러한 수문/생태시스템의 상호관계를 활용하고 모형의 형태를 국내 식생에 대한 생리학적 특성에 맞게 변화시킬 수 있다면 국내 천변저류지에도 충분히 적용 가능할 것으로 판단된다. 또한 잠재적으로 식생 성장에 영향을 줄 수 있는 다양한 환경조건 예를 들면 영양물질, 토양구조, 토사 퇴적 등을 적용대상지 환경에 맞게 포함하거나 고려할 수 있다면 모형의 재현성을 더욱 높일 수 있을 것이다.의 기대효과를 가져올 수 있으리라 생각되며 분석된 인자들은 수달 서식지를 위한 하천정비의 기초자료에 유용할 것으로 보인다.따른 유량측정망을 구축하는 것이다.의 의사결정 지원 도구가 될 것이다. 따라서, 본 연구에서는 도시유역의 물순환 해석을 위한 일련의 과정, 즉 자료의 조사 및 취득에서부터 물순환 해석 모형을 이용한 정량적 현황파악, 물순환 개선 기법 및 평가를 수행함에 있어 주요 착안점 및 실무에서의 기술적 가이드를 제공하고자 하였으며, 보다 세밀한 도시유역의 물순환 해석을 위하여 우리나라와 일본에서 적용이 활발한 물리적 기반의 분포형 모형(WEP, SHER, SWMM)의 적용사례를 통하여 국내 도시하천의 물순환 해석에 활용함에 있어서의 실질적인 적용절차 등을 제시하고자 하였다. 한다.호강유역의 급격한 수질개선을 알 수 있다.世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와 동년대에 동일한 목적으로 찬술되었음을 알 수 있다. $\ulcorner$경상도실록지리지$\lrcorner$(慶尙道實錄地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.545-554
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• 2017

Birnessite is one of the dominant Mn (oxyhydr)oxide phases commonly found in soil and deep ocean environments. It typically occurs as nano-sized and poorly crystalline aggregates in the natural environment. It is well known that birnessite participates in a wide variety of bio/geochemical reactions as a reactive mineral phase with structural defects, cation vacancies, and mixed valences of structural Mn. These various bio/geochemical reactions control not only the fate and transport of inorganic and organic substances in the environment, but also the formation of diverse Mn (oxyhydr)oxides through birnessite transformation. This review assessed and discussed about the phase transformation of birnessite under a wide range of environmental conditions and about the potential geochemical factors controlling the corresponding reactions in the literature. Birnessite transformation to other types of Mn (oxyhydr)oxides were affected by dissolved Mn(II), dissolved oxygen, solution pH, and co-existing cation (i.e., $Mg^{2+}$). However, there still have been many issues to be unraveled on the complex bio/geochemical processes involved in the phase transformation of birnessite. Future work on the detail mechanisms of birnessite transformation should be further investigated.

• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.421-426
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• 2009

The purpose of this study was to identify soil physical characteristics as guideline for high yield potential in ginseng cultivated field which produced 6 years root. Harvest yields of ginseng to be divided by parent rock was in order of phyllite and red shale 3.1 kg/$3.3\;m^2$ > granite and gneiss schist 3.0 kg > basalt 2.6 kg > porphyry 2.2 kg in upland and forest soil. Also, with classified by topography, it was in order of foot slope and alluvial fan 3.2 kg/$3.3\;m^2$ > valley 3.0 kg > low hill 2.9 kg > hill, lave flow and dilluvial terrace 2.8 kg in survey tilth. Class determination of soil texture, it was in order of sandy loam 3.1 kg/$3.3\;m^2$ > loam and silt loam 3.0 kg > clay loam 2.9 kg > silt clay loam 2.8 kg in survey tilth. Slope condition of farming land, in case of sloping (2~7%), it was 3.1 kg/$3.3\;m^2$ but deep sloping (15~30%) caused decreasing harvest yield. In drainage classes (excessively, well and moderately well), there was no significantly different in harvest yields. Relationship between harvest yield and soil series, Production sites as yielding 3.0 kg/$3.3\;m^2$ were seven sites, also it was contained 14 soil series. Production sites as yielding 2.5~3.0 kg/$3.3\;m^2$ were eleven sites, it was contained 16 soil series. Production sites as yielding 2.0~2.5 kg/$3.3\;m^2$ were 10 sites, it was contained 4 soil series.

• Resources Recycling
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• v.26 no.2
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• pp.80-88
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• 2017

Globally, there has been a lot of research related to recycling coal ash from power plant stations. This research is happening because there is a considerable shortage of sites for reclamation of increased coal ash every year. In addition, a variety of environmental pollutants have appeared because of mining activity. Abandoned coal mine, pits, and mine tailing piles caused pollutants to come to the surface resulting in serious damage for humans and the environment. Therefore in this study, we investigated whether or not coal ashes have the ability to prevent several environmental problems by mining in Korea and a manageable form recycling coal ashes. In overseas countries, there is a sufficient field of applicable cases where coal ash is used for neutralizing AMD (Acid Mine Drainage), covering of the waste materials, grouting, and soil amendments. However in Korea, since the coal ash is classified as a 'waste', there is an insufficient field applicable cases so far. Therefore it is necessary to establish a specific standard and management system for the utilization of coal ash based on the relevant precedent cases applied abroad in order to prevent environmental pollution caused by mining activity in Korea.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.131-135
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• 1999

The objective of this research was to improve moisture retention capacity of pine bark. To achieve this, barks were ground with Wiley mill of hammer mill and were blended with recycled rockwool. Then, changes of soil physical properties were determined. The percentage of particles larger than 5.6 mm was 86.5% in raw materials. The percentage of particles larger than 1 mm decreased and those of particles smaller than 1 mm increased by grinding with Wiley mill or hammer mill. Grinding with Wiley mill showed better effect than those of hammer mill in decreasing particle size distribution. Grinding resulted in decreased total porosity (TP) and air space (AS) and increased container capacity (CC) and residual water content (RW), indication improved moisture retention capacity. The material ground with Wiley mill, than blended with 50% recycled rockwool had 81.1%, 67.7%, 13.5% and 235 ml in TP, CC, AS and RW, respectively. These results indicated that moisture retention capacity was improved by blending with recycled rockwood, but aeration of root media was much better than those of peat+vermiculite(1:1, v/v), which is commonly used in commercial production.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.507-522
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• 2021

Specific survey objectives often cannot be met using only one geophysical method, as each method's results are influenced by the specific physical properties of subsurface materials. In particular, areas susceptible to geological hazards require investigation using more than one method in order to reduce risks to life and property. Instead of analyzing the results from each method separately, this work develops a four-quadrant criterion for classifying areas of levees as safe or weak. The assessment is based on statistically determined thresholds of seismic velocity (P-wave velocity from seismic refraction and S-wave velocity from multichannel analysis of surface waves) and electrical resistivity. Thresholds are determined by subtracting the standard deviation from the mean during performance testing of this correlation technique applied to model data of four horizontal and inclined fracture zones. Compared with results from the crossplot of resistivity and P-wave velocity, crossplot analysis using resistivity and S-wave velocity data provides more reliable information on the soil type, ground stiffness, and lithological characteristics of the levee system. A loose and sandy zone (represented by low S-wave velocity and high resistivity) falling within the second quadrant is interpreted to be a weak zone. This interpretation is well supported by the N values from standard penetrating test for the central core.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.273-282
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• 2023

Hypochaeris radicata, native to Europe and Eurasia, is a perennial plant of the Asteraceae family. In Korea, H. radicata was reported in 1992, mainly in Jeju Island, and gradually spreading to the inland. It overwinters in the form of a rosette and blooms yellow flowers from May to June. H. radicata propagates by seeds and rhizomes. The germination temperature of the seed is 15/20℃ (day/night), and the rhizome forms a new plant at a depth of 2-3cm in the soil. The roots of H. radicata secrete allelochemicals that inhibit the development of other plants. Some use it as a salad or forage substitute but to a limited extent. However, extensive research on ampicillin contained in H. radicata has been conducted, and its anticancer and anti-inflammatory effects have been recognized. There are only a few methods to manage H. radicata both culturally and physically. In orchards, soil treatments such as oxyfluorfen and diclobenil, or nonselective foliar treatments such as glufosinate-ammonium and glyphosate are used. Notably, there are no known biological control agents.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.2
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• pp.88-100
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• 1998

Since fractures may serve as major conduits of groundwater flow in crystalline rocks, characterization of conductive fractures is especially important for interpretation of flow system. In this study, characterization of fractures to investigate hydraulically conductive fractures in gneisses at an abandoned mine area was performed. The orientation, width, length, movement sense, infilling materials, spacing, aperture, roughness of both joints and faults and intersection and connectivity to other joints were measured on outcrops. In addition, characteristics of subsurface fractures were examined by core logging in five boreholes, of which the orientations were acquired by acoustic televiewer logging from three boreholes. The dominant fracture sets were grouped from outcrops; GSet 1: N50-82$^{\circ}$E/55-90$^{\circ}$SE, GSet 2: N2-8$^{\circ}$E/56-86$^{\circ}$SE, GSet 3: N46-72$^{\circ}$W/60-85$^{\circ}$NE, GSet 4:Nl2-38$^{\circ}$W/15-40$^{\circ}$SW and from subsurface; HSet 1: N50-90$^{\circ}$E/55-90$^{\circ}$SE, HSet 2: N10-30$^{\circ}$E/50-70$^{\circ}$SE, HSet 3: N20-60$^{\circ}$W/50-80$^{\circ}$NE, HSet 4: N10-50$^{\circ}$E/$\leq$40$^{\circ}$NW. Among them, GSet 1, GSet 3 and HSet 1, HSet 3 are the most intensely developed fracture sets in the study area. The mean fracture spacings of HSet 1 are 30-47cm and code 1 fractures, such as faults and open fractures, comprise 21.0-42.9 percent of the whole fractures in each borehole. HSet 3 shows the mean fracture spacings of 55-57cm and the ratio of code 1 fractures is 15.4-26.9 percent. In spite of the mean fracture spacing of 239cm, code 1 fractures of HSet 4 have the highest ratio of 54.5 percent. From the fact that faults or open fractures have high hydraulic conductivity, it can be inferred that the three fracture sets of N55-85$^{\circ}$E/50-80$^{\circ}$SE, N20-60$^{\circ}$W/50-75$^{\circ}$NE and N10-30$^{\circ}$E/$\leq$30$^{\circ}$NW from a fracture system of relatively high conductivity. It is indirectly verified with geophysical loggings and constant injection tests performed in the boreholes.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.224-232
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• 2000

Inorganic nutrient concentrations in relation to springtime physical parameters of the Yellow Sea were investigated during April 1996. Three major water masses, i.e., the Yellow Sea Warm Current Water (YSWC), Coastal Current Water (CCW) and Changjiang River Diluted Water (CRDW), prevailed in the study area. Water masses were vertically wel1 mixed throughout the study area, and nutrients were supplied adequately from bottom to surface layer. As result of ample nutrients supplied by vertical mixing together with progressed daylight condition, springtime phytoplankton blooms were observed, which was responsible for the depletion of inorganic nutrients in surface water column. Low nutrients concentration in bottom water of the central Yellow Sea (Stn. D9; nitrate: <2 ${\mu}$M, phosphate: <0.3 ${\mu}$) was associated with the entrance of YSWC which is characterized by high temperature and salinity. Influenced by runoff and vertical tidal mixing, CCW with high nutrient concentrations probably associated with China and Korea coastal waters with high nutrients concentration. For the local scale of inorganic nutrient distribution, nutrient transfers from coast to central areas were limited due to restriction imposed by tidal fronts (Stn. D6) and thus affected the horizontal nutrient profiles. Relatively high phytoplankton biomass was observed in the tidal front (Chl-${\alpha}$=12.38 ${\mu}$gL$^{-1}$) during the study period. Overall, the springtime nutrient distribution patterns in the Yellow Sea appeared to be affected by: (1) Large-scale influx of YSWC with low nutrient concentrations and CCW with high nutrient concentrations influenced by Korea and China coastal waters; (2) vertical mixing of water mass and phytoplankton distribution; and (3) local-scale tidal front as well as phytoplankton blooms alongthe tidal front.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.425-434
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• 2008

Arsenic contamination in soil and groundwater has recently been one of the most serious environmental concerns. This arsenic contamination can be originated from natural or anthropogenic sources. It has been well known that arsenic behavior in geo-environmental is controlled by various oxides or hydroxides, such as those of iron, manganese, and aluminum, and clay minerals. Among those, particularly, iron (oxy)hydroxides are the most effective scavengers for arsenic. For this reason, this study characterized arsenic adsorption of magnetite which is a kind of iron oxide in nature. The physicochemcial features of the magnetite were investigated to evaluate adsorption of arsenite [As(III)] and arsenate [As(V)] onto magnetite. In addition to experiments on adsorption equilibria, kinetic experiments were also conducted. The point of zero charge (PZC) and specific surface area of the laboratory-synthesized magnetite used as an arsenic adsorbent were measured 6.56 and $16.6\;g/m^2$, which values seem to be relatively smaller than those of the other iron (oxy)hydroxides. From the results of equilibria experiments, arsenite was much more adsorbed onto magnetite than arsenate, indicating the affinity of arsenite on magnetite is larger than arsenate. Arsenite and arsenate showed adsorption maxima at pHs 7 and 2, respectively. In particular, adsorption of arsenate decreased with increase in pH as a result of electrical repulsion caused by anionic arsenate and negatively-charged surface of magnetite. These results indicate that the surface charge of magnetite and the chemical speciation of arsenic should be considered as the most crucial factors in controlling arsenic. The results of kinetic experiments show that arsenate was adsorbed more quickly than arsenite and adsorption of arsenic was investigated to be mostly completed within the duration of 4 hours, regardless of chemical speciation of arsenic. When the results of kinetic experiments were fitted to a variety of kinetic models proposed so far, power function and elovich model were evaluated to be the most suitable ones which can simulate adsorption kinetics of two kinds of arsenic species onto magnetite.