• 자원환경지질
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• 제32권2호
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• pp.177-187
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• 1999

Gravity, magnetic and VLF surveys were conducted to investigat the structural stability and hazards associated with the Ubong landfill in Pohang City, which has been built to dump industrial wastes. In 1994, the collapse of a bank happened in the 6th landfill site due to sudden heavy rain, and a large quantity of waste materials flowed out to the nearby landfill sites, factories and roads. We used $10{\times}10m$ resolution DEM data for gravity reductions. The maximum variation of the terrain effect in the survey area is about 0.5 mgal and the terrain effect is large in the vicinity of bank boundary. The Bouguer gravity anomaly map shows the effect due to the variatino of thickness and type of waste materials. The small negative gravity anomaly increases from the 9th site to the 6th site. The small negative gravity anomaly of the 9th site reflects the relatively shallow dumping depth of average 14.5 m in this site and increased density of waste materials by the repeated stabilization process of soil overlaying. The 6th site is located at the center of the former valley and rainfall and groundwater are expected to flow from south-east to north-west. Therefore, considering the previous accident of mixing waste and bank materials at the north-west boundary of the landfill, there may be some environmental problems of leakage of contaminated water and bank stability. The complex inversion technique using Simulated annealing and Marquardt-Levenberg methods was applied to calculate three-dimensional density distribution from gravity data. In the case of 6th site, it is apparent that the landfill had been dumped in four sectors. However, most part of the 9th site and showed that high magnetic industrial wastes were concentrated in the 6th site. The result of magnetic survey showing low magnetic anomalies along the boundaries of two sites is similar to that of gravity data. The VLF data also reveals four divided sectors in the 6th site, and overall anomaly trend indicates the directio of former valley.

• 대한공간정보학회지
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• 제20권3호
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• pp.3-10
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• 2012

화성의 계곡망 추출 및 체적 분석은 과거 화성에 존재했을 지표수의 흐름을 규명할 수 있는 중요한 정보를 제공하고 있다. 이를 위해 본 연구에서는 기존의 이미지 프로세싱 분석을 대체할 수 있는 포인트 클라우드 기반의 지형 필터링 알고리즘을 사용한 새로운 방법론을 제시하였다. 우선 추출하고자 하는 계곡을 지면으로부터 분류하기 위해 대상지역에서 취득한 포인트 클라우드 자료의 고도값을 역전한 뒤, Adaptive TIN 필터링을 적용하였다. 분류한 지면과 대상물의 포인트 클라우드로부터 각각 ground DEM과 object DEM을 생성하고, 격자 단위로 두 DEM 간의 고도차와 object DEM으로부터 취득한 계곡 면적을 곱함으로써 최종적으로 계곡의 체적을 추정하였다. 화성 Tuscaloosa 분화구에 인접한 두 계곡을 대상으로 추정된 체적의 총 합은 약 $1.41{\times}10^{11}m^3$으로 Tuscaloosa 분화구 내 퇴적물의 체적 및 기존의 이미지 프로세싱 기법인 BTH 결과와 각각 12% 및 16%의 차이를 나타내었다.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.439-443
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• 2006

Soil properties of Quercus variabilis forest on Youngha valley at Mt. Worak National Park were studied as a part of Korea National Long-Term Ecological Research. Soil sampling was carried out along the 50 cm soil depth with 10cm intervals at every quarter from May 2005 through July 2006. Fresh soil was used for $NH_4{^+}-N,\;NO_3{^-}-N$, and soil water content determination. Remaining soils were air dried in the shade, and then used for determination of soil pH, T-N, T-P and exchangeable cation. Average soil organic matter in top soil was $8.5{\pm}1.2%$ and decreased with soil depth. Bulk density of top soil was $0.82{\pm}0.07g/cm^3 $and increased with soil depth. Soil organic matter and bulk density showed a negative linear correlation ($R^2=0.8464$). Soil pH in top soil and subsoil was similar. T-N, $NH_4{^+}-N,\;NO_3{^-}-N$ and T-P in top soil were $1.9{\pm}0.5mg/g,\;7.3{\pm}1.0mg/kg,\;2.0{\pm}0.4mg/kg\;and\;0.2{\pm}0.05mg/g$, respectively. $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in top soil were $84.6{\pm}24.4,\;408.8{\pm}137.8\;and\;93.4{\pm}23.0mg/kg$, respectively. They decreased with soil depth. Amounts of organic matter, T-N, $NH_4{^+}-N,\;NO_3{^-}-N$, T-P, $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in 50 cm soil depth were 250.9, 3.45, 0.025, 0.003, 0.639, 0.181, 0.845 and 0.302 ton $ha^{-1}\;50cm-depth^{-1}$, respectively.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권1호
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• pp.1-14
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• 2021

The study has been carried out with an objective to prepare Siberian roe deer habitat potential maps in South Korea based on three geographic information system-based models including frequency ratio (FR) as a bivariate statistical approach as well as convolutional neural network (CNN) and long short-term memory (LSTM) as machine learning algorithms. According to field observations, 741 locations were reported as roe deer's habitat preferences. The dataset were divided with a proportion of 70:30 for constructing models and validation purposes. Through FR model, a total of 10 influential factors were opted for the modelling process, namely altitude, valley depth, slope height, topographic position index (TPI), topographic wetness index (TWI), normalized difference water index, drainage density, road density, radar intensity, and morphological feature. The results of variable importance analysis determined that TPI, TWI, altitude and valley depth have higher impact on predicting. Furthermore, the area under the receiver operating characteristic (ROC) curve was applied to assess the prediction accuracies of three models. The results showed that all the models almost have similar performances, but LSTM model had relatively higher prediction ability in comparison to FR and CNN models with the accuracy of 76% and 73% during the training and validation process. The obtained map of LSTM model was categorized into five classes of potentiality including very low, low, moderate, high and very high with proportions of 19.70%, 19.81%, 19.31%, 19.86%, and 21.31%, respectively. The resultant potential maps may be valuable to monitor and preserve the Siberian roe deer habitats.

• Mycobiology
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• 제37권1호
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• pp.10-16
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• 2009

The purpose of this study is to understand spatio-temporal changes of active fungal biomass and water in Tricholoma matsutake soil colonies during the mushroom fruiting season. The active fungal biomass was estimated by analyzing ergosterol content at four different points within four replicated locations in a single circular T. matsutake colony at Ssanggok valley in the Sogri Mt. National Park in Korea during 2003 to 2005. The four points were the ahead of the colony, the front edge of the colony and 20 cm and 40 cm back from the front edge of the colony. Ergosterol content was 0.0 to 0.7 ${\mu}g$ per gram dried soil at the ahead, 2.5 to 4.8 ${\mu}g$ at the front edge, 0.5 to 1.8 ${\mu}g$ at the 20 cm back and 0.3 to 0.8 ${\mu}g$ at the 40 cm back. The ergosterol content was very high at the front edge where the T. matsutake hyphae were most active. However, ergosterol content did not significantly change during the fruiting season, September to October. Soil water contents were lower at the front edge and 20 cm back from the front edge of the colony than at the ahead and 40 cm back during the fruiting season. Soil water content ranged from 12 to 19% at the ahead, 10 to 11% at the edge, 9 to 11% at the 20 cm back and 11 to 15% at the 40 cm back. Our results suggest that the active front edge of the T. matsutake soil colony could be managed in terms of water relation and T. matsutake ectomycorrhizal root development.

• Geomechanics and Engineering
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• 제34권5호
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• pp.577-595
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• 2023

A dynamic triaxial discrete element numerical model of lightweight soil was established using the discrete element method to study the microscopic mechanism of expanded polystyrene (EPS) particles in the soil under cyclic loading. The microscopic parameters of the discrete element model of the lightweight soil were calibrated depending on the dynamic triaxial test hysteresis curves. Based on the calibration results, the effects of the EPS particles volume ratio and amplitude on the contact force, displacement field, and velocity field of the lightweight soil under different accumulated strains were studied. The results showed that the hysteresis curves of lightweight soil exhibit nonlinearity, hysteresis, and strain accumulation. The strain accumulated in remolded soil is mainly tensile strain, and that in lightweight soil is mainly compressive strain. As the volume ratio of EPS particles increased, the contact force first increased and then decreased, and the displacement and velocity of the particles increased accordingly. With an increase in amplitude, the dynamic stress of the particle system increased, and the accumulation rate of the dynamic strain of the samples also increased. At 5% compressive strain, the contact force of the particles changed significantly and the number of particles deflected in the direction of velocity also increased considerably. These results indicated that the cemented structure of the lightweight soil began to fail at a compressive strain of 5%. Thus, a compressive strain of 5% is more reasonable than the dynamic strength failure standard of lightweight soil.

• 한국산림과학회지
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• 제77권4호
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• pp.401-413
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• 1988

내장산국립공원 내장사지구의 이용객심리행태 및 환경에 대한 이용객영향을 조사하기 위해서 3개의 주요피크닉지역에서 설문조사와 순간밀도조사를, 주요통과지점에서 출입객 수 조사를 하였으며 환경영향은 실측조사를 하였다. 총탐방객 수는 1984년부터 100만명/연 수준으로 안정을 보이고 있었다. 환경영향은 등산로와 케이블카 종점부근, 전망대와 금선계곡간 사면에서 매우 심하였다. 봄철 피크시에는 약 5,000명, 가을 단풍철 피크시에는 약 53,000 명이 동시에 체류하는 것으로 추정되었다. 총입장객 중 약20% 가금선 및 원적계곡을 이용하였고, 나머지 80%는 잔디광장, 케이블카만 이용하고 퇴장하는 것으로 나타났다. 이용특성은 원거리형 국립공원형이었으며, 가을철 단풍구경이 주이용동기이었다. 이용면적증가에 따른 이용객의 만족도는 유의하게 차이를 나타내지 않았으며, 직각회전방법에 의한 인자분석결과, 이용객의 만족도에 크게 영향을 미치는 제1인자는 주변경관에 관한 인자로 자연파괴, 혼잡도, 소음, 주변청결상태 순으로 부하되어 있었다. 다음으로 영향을 미치는 제2인자는 시설관리인자로서 화장실 수, 쓰레기통 수, 식수량, 안전성 순으로 부하되어 있었다.

• 한국환경농학회지
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• 제30권2호
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• pp.209-215
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• 2011

물방개과의 전국분포를 파악하고자 2005년부터 2007년까지 3년간 전국 138개 시 군에 있는 곡간지 논과 평야지 논 총 290지점에서 조사하였다. 우리나라 전국의 논에서 확인된 물방개과는 총 15속 26종이었다. 전국 논에서 채집된 물방개과의 26종 중 곡간지 논에서는 24종이 확인되었고, 평야지 논에서는 19종이 확인되었다. 논에 서식하는 물방개과 중에서 전국적으로 그 출현빈도가 매우 낮은 희귀종으로는 동쪽깨알물방개, Laccophilus lewisioides, 노랑무늬물방개, 외줄물방개, 점톨물방개, 맵시등줄물방개, 검정머리땅콩물방개, 큰알락물방개, 알락물방개, 잿빛물방개 및 물방개로 총 11종으로 확인되었다. 채집된 물방개류 종별 평균 크기는 2.0 mm ~ 35.0 mm로 나타났다. 들녘 논에 비교적 넓게 분포하는 종은 꼬마물방개, 애기물방개 2종 이었고, 큰땅콩물방개, 땅콩물방개, 모래무지물방개 등은 들녘 논에서 거의 발견되지 않는 희귀종이었다. 희귀종을 제외한 대부분의 물방개류는 전국의 곡간지 논에서 발견되었다. 특이적으로 모래무지물방개는 거의 경상남도에서 발견되었으며, 가는줄물방개는 경상남도를 제외한 지역에서만 발견되어 이 두 종간에 상호 경쟁관계가 있는 것으로 생각된다. 이와 같이 거의 모든 물방개류의 전국적 분포범위는 곡간지 논의 교란형태 즉 물의 공급방식, 비오톱과의 연계성 및 각 종의 몸 크기의 차이에 따른 먹이에 대한 경쟁관계 등이 복합적으로 작용하여 평야지에서의 물방개과 수서생물의 분포를 제한하는 것으로 판단된다. 논 서식 생물에 대한 전국적인 분포조사는 국가생물다양성 보전의 측면에서 중요하며, 서식지의 물리적 환경 및 영농관리형태와의 연계성에 대한 정밀한 분석을 통하여 이들 종의 생물다양성을 증진시키는 요인을 찾아내는 것이 필요하다.

• 한국전통조경학회지
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• 제30권1호
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• pp.113-124
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• 2012

별서정원은 동양적 자연관과 유교적 정치상황이 맞물려 조선시대 사대부 사이에 성행하였던 우리나라의 독특한 조경양식이라 할 수 있다. 특히 경상도에는 경관이 수려한 낙동강과 그 지천의 주변에 주자학의 가르침을 따르며 살다간 선비들의 흔적을 엿볼 수 있는 별서정원과 별서를 경영하고 즐겼던 사대부들의 행장, 그들의 시문과 정자기 등이 전해진다. 경상북도 풍기에 위치한 금선정 일원은 퇴계 이황의 대표적 제자이자 목민관이었던 금계 황준량(1517-1563)의 별서지다. 금양정사는 황준량의 수양처였으며 금선정은 일찍 세상을 떠난 황준량을 위해 스승과 제자가 지은 정자이다. 금선정이 위치한 금선계곡은 풍광이 아름다우며 금선계곡을 따라 펼쳐진 소나무숲은 금선정 일원의 풍광을 더욱 아름답게 한다. 금선정은 빼어난 자연풍경뿐 아니라 황준량과 관련된 문헌과 이야기가 전해진다. 본 연구는 금선정의 명승적 가치를 규명하고자 금선정의 주변현황, 지형 식생 수계 조사를 통하여 자연환경과 황준량과 이황의 '금계집', 류운룡의 '금계집', 홍경렴의 '금계정사중수기' 등 인문환경을 분석하였다. 분석 결과 경관적으로 금선계곡(금계계곡) 일원은 금선정의 정자와 전면의 맑은 계류와 소나무 숲이 아름다운 조화를 이룬 뛰어난 경관미를 지니고 있으며 '금계집'과 같은 문집의 시문에서 '아름답다'와 '명승'이라는 용어를 사용한 점과 계곡 주변에 모임의 장소였던 역사문화경관을 살펴볼 때 명승자원으로써 가치가 충분하다. 최근 들어 별서명승의 문화재지정 사례가 증가되고 별서정원의 명승적 가치를 인정받고 있다. 따라서 본 연구를 통해 금선정 일원이 별서명승으로 지정할 수 있는 준거를 마련하고자 하였다.

• 한국물환경학회지
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• 제26권5호
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• pp.761-767
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• 2010

This study introduces a model of territorial analysis on Chungcheongnam-do Nonsan-chun valley area, which gives an example of a method of selecting the management area for non-point pollution source from land use to help eliminate its source. High discharge load per unit area signify high level of land ratio with high level of basic unit of development load (including factory sites, school sites, roadways), which mean that there are a significant level of urbanization. It is these areas with the examination of the water quality of the nearby river that should be considered as the management area for non-point pollution source. Thus, the management area for non-point pollution source should be sought in areas with high discharge load per unit area and high density of water pollution area. When level of drainage is high the pollution density level is relatively lower, and when the level of drainage is low the density level is relatively higher. The level of pollution from non-point pollution source is much lower with more water flowing through. The possible non-point pollution source areas that were selected with these standards were then examined with the distance from the river, the slope angle, land usage, elevation, BOD discharge density load, T-N discharge density load, T-P discharge density load, and were given a level one through five. Out of the possible areas Nonsan-si Yeonmu-eup Anshim-li was the densest area, and it was given level one. The level one area should be examined further with the field analysis to be selected as the actual management area for non-point pollution source.