• 한국응용곤충학회지
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• 제25권3호
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• pp.175-182
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• 1986

경제작물(經濟作物) 주산지(主産團地)의 식물기생선충 종류(種類), 분포상태(分布狀態) 및 기생선충 밀도(密度)에 따른 피해정도(被害程度)를 파악(把握)코자 채 및 깔데기법(法)으로 마늘, 감자 등 18개(個) 작물(作物) 3,226포장(圃場)을 조사(調査)하여 1. 16속(屬)(genus)의 기생선충을 분류(分類)하였음. 2. 마늘의 구근선충은 포장검출율(圃場檢出率)이 81% 이며 이중 마늘 1구당(球當) 30마리 이상의 선충이 검출(檢出)된 포장(圃場)은 96%로 이러한 포장에서는 피해(被害)가 예상(豫想)됨. 3. 고추, 오이, 토마토, 땅콩에는 뿌리혹선충이 주요(主要) 기생선충이며, 포장검출율(圃場檢出率)이 높을 뿐더러 선충밀도가 토양(土壤) 100gr당(當) 100마리 이상되는 포장(圃場)이 각각 35%, 17%, 28%, 31%로 이러한 지역(地域)은 피해(被害)가 예상(豫想)됨. 4. 고추에 있어서는 Meloidogyne hapla, M. incognita가, 참깨에서는 Helicotylenchus dihystera, 사과에는 Pratylenchus vulnus, P. penetrans, 포도에서는 Meloidogyne hapla, 뽕나무에서는 Paratytylenchus projectus, P. aciculus, P. morius, Meloidogyne arenaria, Helicotylenchus dihystera 가 각각 주요(主要) 선충이었다. 5. 고추의 경작년수(耕作年數)가 많을수록 뿌리혹선충의 밀도(密度)가 높았으며 5년(年) 연작시(連作時) 토양(土壤) 200gr당(當) 3,500마리나 되었다.

• 한국환경복원기술학회지
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• 제19권3호
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• pp.103-119
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• 2016

This study aims to assess habitat feature on the large-scale spawning ground of the Boreal Digging Frog Kaloula borealis in Daemyung retarding basin of Daegu, and to analyze the relationships between species abundance and meteorological factors for each habitat. Fifty-seven(57) pitfalls were installed to collect species abundance of 4 survey regions, and high-resolution satellite image, soil sampling equipment, digital topographic map, and GPS were used to develop habitat features such as terrain, soil, vegetation, human disturbance. The analysis shows that the frog is most abundant in sloped region with densely herbaceous cover in southern part of the retarding basin. In the breeding season, lowland regions, where Phragmites communis and P. japonica dominant wetlands and temporary ponds distributed, are heavily concentrated by the species for spawning and foraging. Located in between legally protected Dalsung wetands and lowland regions of the retarding basin, riverine natural levee is ecologically important area as core habitat for Kaloula borealis, and high number of individuals were detected both breeding and non-breeding seasons. Temperate- and pressure-related meteorological elements are selected as statistically significant variables in species abundance of non-breeding season in lowland and highland regions. However, in sloped regions, only a few variables are statistically significant during non-breeding season. Moreover, breeding activities in sloped regions are statistically significant with minimum temperature, grass minimum temperature, dew point temperature, and vapor pressure. Significant meteorological factors with habitat features are effectively applied to establish species conservation strategy of the retarding basin and to construct for avoiding massive road-kills on neighboring roads of the study sites, particularly post-breeding movements from spawning to burrowing areas.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권5호
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• pp.51-61
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• 2009

본 연구에서는 부산지역 지하수수질측정망 80개소를 대상으로 방사성물질의 특성을 연구하였다. 우라늄의 전체 평균 농도는 $4.33\;{\mu}g/L$이였고, 최대 평균농도는 $171.55\;{\mu}g/L$이였다. 미국 먹는물기준인 $30\;{\mu}g/L$을 초과한 곳은 1곳, WHO 권고기준인 $15\;{\mu}g/L$을 초과한 곳은 4곳으로 나타났다. 라돈의 전체 평균농도는 169 pCi/L이였고, 최대 평균농도는 1,850 pCi/L이였다. 미국 먹는물기준인 4,000 pCi/L WHO 권고기준인 2,700 pCi/L을 초과한 곳은 단 한곳도 없었다. 전알파의 전체 평균농도는 0.3pCi/L이였고 최대 평균농도는 6.9 pCi/L로 다른 방사성물질에 비하여 미미한 수준으로 나타났다. 지하수중에서 방사성물질의 평균 농도는 낮은 편이지만 미량이나마 검출되는 바 국민건강상 위해를 예방하기 위하여 먹는물 수질기준 둥 관리대책 마련의 필요성이 요구된다. 또한 우라늄이 고농도로 검출되는 일부 지점에 대해서는 정밀한 검토를 거쳐 폐공 조치 등 적절한 조치가 필요할 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.51-62
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• 2012

Effects of climate change on groundwater system requires understanding the groundwater system in temporal and spatial scales through the long-term monitoring. In this study, the spatio-temporal variations of groundwater were analyzed through the continuous observation of water level, electrical conductivity (EC) and water temperature with automatic data-loggers and sampling in a Gwangneung catchment, Korea, for the four years from 2008 to 2011. Groundwater monitoring were performed at the nest-type wells, MW1 and MW2, located in upsteam and downstream of the catchment, respectively. During the survey period, both the total amount of annual precipitation and the frequency of concentrated rainfall have increased resulting in the elevation of runoff. Water level of MW1 showed no significant fluctuations even during the rainy season, indicating the confined groundwater system. In contrast, that of MW2 showed clear seasonal changes, indicating the unconfined system. The lag-time of temperature at both wells ranged from one to three months depending on the screened depths. Results of chemical analyses indicated that major water compositions were maintained constantly, except for the EC decreases due to the dilution effect. Values of the stable-isotope ratios for oxygen and deuterium were higher at MW2 than MW1, implying the confined system at the upstream area could be locally developed.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권5호
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• pp.39-48
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• 2021

Analysis of the change in water content and distribution was conducted according to the supply of recirculation water to a landfill. An excavation sample analysis showed that the recirculation water injection zone had water content 8.8% point higher than that of the non-injection zone, after 8 months of operation. And due to the influence of recirculation water supply by vertical wells in injection zones, the water content increases along with depth more clearly than non-injection zone. According to an electrical specific-resistivity survey after 13 months of operation, the water content got higher towards the bottom of the landfill. The water transmission coefficient is 8.72×10^-4 cm/sec for injection zones and 3.36×10^-5 cm/sec for the intermediate cover layer; analysis shows that the intermediate cover layer may affect the penetration velocity of water supplied by the horizontal injection tube. For the scientific design and operation of re-injection facilities, it was deemed necessary to follow-up research on the residence time and behavior of re-injection water considering the ratio of recirculation water supply in horizontal and vertical tubes, and pitcher coefficient of intermediate and waste layers.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권1호
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• pp.65-75
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• 2021

We investigated hydrochemical and stable isotope characteristics of groundwater in a large agricultural plain, the Honam plain, to evaluate the adequacy of agricultural water supply. For preliminary assessment for the area, we collected 23 groundwater samples from domestic wells and conducted hydrochemical and water stable isotope analysis. Groundwater in the study area is mainly Ca-HCO3 type resulting from water-rock interactions. Stable oxygen and hydrogen isotopic compositions indicated that recharge water is derived from precipitation while some sampling sites had evaporation signatures. Irrigation water quality using sodium absorption ratio and salinity hazard showed most of the groundwater samples were found to be suitable for irrigation. The groundwater in the southwestern part of the study area was affected by both seawater intrusion and agricultural activities, indicating a higher possibility of groundwater contamination near the coastal areas. Elevated concentrations of nitrate and phosphate ions in the groundwater are considered to be influenced by anthropogenic activities such as fertilizer application. It is expected that this study would be able to provide preliminary information on groundwater quality for agricultural water supply in the Mangyeong-Dongjin watershed.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2802-2811
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• 2023

In a first-of-its-kind study, terrestrial radionuclide concentrations were measured in 35 topsoil samples from the outskirts of Dhaka using HPGe gamma-ray spectrometry to assess the radiological consequences of such a vast number of brick kilns on the plant workers, general as well as dwelling environment. The range of activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K is found at 19 ± 3.04 to 38 ± 4.94, 39 ± 5.85 to 57 ± 7.41, and (430 ± 51.60 to 570 ± 68.40) Bq/kg, respectively. ²³²Th and ⁴⁰K concentrations were higher than the global averages. Bottom ash deposition in lowlands, fly ash buildup in soils, and the fallout of micro-particles are all probable causes of the elevated radioactivity levels. ¹³⁷Cs was found in the sample, which indicates the migration of ¹³⁷Cs from nuclear accidents or nuclear fallout, or the contamination of feed coal. Although the effective dose received by the general public was below the recommended dose limit but, most estimates of hazard parameters surpass their respective population weighted global averages, indicating that brick kiln workers and nearby residents are not safe due to prolonged exposures to terrestrial radiation. In addition, the soil around sampling sites is found to be unsuitable for agricultural purposes.

• 대한토목학회논문집
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• 제26권2C호
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• pp.89-98
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• 2006

본 연구에서는 해성점토의 전단강도를 증진시킬 목적으로 철과 알루미늄 전극을 직접 삽입한 후 전극을 분해하여 지반 고결화 효과를 유발하였다. 이를 위해 남해안에서 채취한 실제 해성점토에 대해 실내 토조를 이용한 파일럿 실험을 실시하였고, 각각 철과 알루미늄을 삽입한 후 일정 고전류(2.5A)를 적용시켰다. 고결화에 의한 영향을 파악하고자 실험 종료 후에는 콘관입시험기를 이용하여 비배수 전단강도를 측정하였으며, 위치별 함수비와 pH 및 전기전도도를 측정하여 철과 알루미늄의 전극분해에 의한 고결화 효과를 간접적으로 판단하였다. 철 전극 전기분해 실험 결과, 양(+)극부 근처에서의 함수비는 초기에 비해 35% 감소하였고, 음극부 근처에서는 13% 증가하였으나, 양극부에서 용출된 철 이온과 흙 입자의 고결화 작용에 의해 전체적으로 측정된 전단강도는 초기에 비해 상당히 증가하였다. 또한 알루미늄 전극을 이용하였을 경우, 철에 비해 비교적 균일한 전단강도 증진효과가 나타났으며, 그 개량정도 역시 더 크게 나타났다.

• 한국농림기상학회지
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• 제12권3호
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• pp.197-206
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• 2010

토지 이용이 다변화된 산지 유역에서 몬순 강우에 의한 환경 영향을 평가하는데 필수적인 기초 자료를 확보하기 위해 수질의 계절간 비교와 강우사상 집중샘플링의 방법을 활용하여 지표수 수질의 시공간적 변이 특성을 조사하였다. 유역 내 토지 이용을 반영하는 지표수 9개 지점을 대상으로 건 우기 수질의 계절적 차이를 비교하고, 2회의 강우사상에 대해 산림과 농경지 하천 2개 지점에서 집중 샘플링을 실시하였다. 대부분의 지점에서 건기보다 우기에 전기전도도와 $Cl^-$ 농도는 더 낮았으나, 총 금속 농도는 우기에 훨씬 더 높았다. 이는 우기에 늘어난 유량에 의해 용존 이온은 희석되고, 토양 침식량은 증가됐기 때문인 것으로 보인다. 한편 18mm의 적은 강우 시에 산림 하천의 수질에서는 거의 변화가 보이지 않은 데 반해, 농경지 하천에서는 부유토사와 용존 물질 농도가 모두 가파른 변화를 보였으며, 452mm의 많은 강우에 대해서는 농경지 하천은 물론 산림 하천에서도 큰 수질 변화를 관찰할 수 있었다. 농경지 하천의 Pb 농도는 부유토사 농도와 높은 양의 상관관계를 보였다. 제한된 샘플링 횟수와 조사지점으로 인해 결과 해석에 신중을 기해야 하겠지만, 전체 결과는 가파른 산지 유역에 농경지가 무분별하게 확장되면 강우의 변동폭과 극단화가 심해질 경우 토양 침식과 그에 따른 환경 영향의 취약도가 증가할 것임을 시사한다.

• 한국환경보건학회지
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• 제36권5호
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• pp.360-372
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• 2010

Concentrations of ambient air particles such as total suspended particulates (TSP), particulate matter $(PM)_{10}$, and $PM_{2.5}$, were monitored simultaneously from May to June, 2007, at four locations at Alashan and Beijing in China, and Seoul and Gosan in South Korea. These monitoring sites are in the pathway of Asian dust (AD) storms traveling from China to the Korean peninsula. An AD event was observed in the Korean peninsula on May 25-26. During the sampling period, the average concentrations of TSP and PM10 were each higher than $150\;{\mu}g/m^3$ in Alashan and Beijing, but not in Seoul and Gosan. The concentration of TSP in Alashan (where the dust storm originated) on the day of the AD event reached $1824.7\;{\mu}g/m^3$, this being the highest concentration of air particles observed during the sampling period. The level was decreased to 15% of this ($274.7\;{\mu}g/m^3$) in Seoul and to 8.7% ($159.0\;{\mu}g/m^3$) in Gosan when the AD was observed two days later in Korea. Gosan, a representative background site in East Asia, displayed the lowest concentration of particles, with this maximal TSP concentration of $159\;{\mu}g/m^3$. Inorganic element contents in the air particles were also measured, and the concentrations in the four different regions compared. Concentrations of anthropogenically-enriched heavy metals in $PM_{10}$ and $PM_{2.5}$, such as lead, arsenic, cadmium, and mercury, were higher in the metropolitan cities of Beijing and Seoul compared to non-industrialized regions of Alashan and Gosan. However, the concentrations of inorganic soil elements including iron, magnesium, aluminum sodium, and manganese, were higher in Alashan compared to those in other sampling sites.