• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.346-346
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• 2017

In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

• 한국연초학회지
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• 제9권2호
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• pp.49-57
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• 1987

This study had been conducted to determine morphological characteristics of soil in the major districts cultivating flue-cured tobacco plant. Also native soil productivities were measured by means of bioassay planting tobacco plant without fertilizer at 87 selected soils through field experiment. Morphological characteristics of troll affecting the dry weight of tobacco leaves cultivated in the field were investigated Among soil morphological characteristics, topograpy, slope, topsoil depth, soil depth, and soil texture had influenced with high significant on the dry weight of tobacco leaves. For prediction of dry weight (productivity) of tobacco leaves without fertilizer , multiple regression analysis were introduced using soul morphological characteristics. A combination of topography, slope, topsoil depth, and soil texture was very reliable for prediction of productivity. The regression equation was y = -16.88 -14, 34$X_1$ +20.43$X_2$ +50.21$X_3$ -7.54$X_4$ +13.45$X_5$ R = $0.670^{**}$ Where $X_1$ : Topography $X_2$ : Slope $X_3$ : Topsoil Depth $X_4$ : Soil Depth $X_5$ : Soil Texture

• 한국지반신소재학회논문집
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• 제17권4호
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• pp.11-19
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• 2018

국내 외에서 사면 붕괴 조기 경보를 위한 모니터링 및 자동측정기에 대한 많은 연구가 있지만 대부분 사면 붕괴 측정기가 사면의 표층에 설치되어 있어 사면의 붕괴 등 재난이 발생되기 전에 감지 및 경보가 가능한 시스템에 대한 연구는 거의 없는 실정이다. 본 연구에서는 록볼트에 센서를 부착하여 사면 붕괴 모의 실험을 수행하였고, 사면 붕괴 초기에 발생하는 사면 거동 특성을 분석하였다. 또한, 숏크리트를 타설한 사면과 자연사면, GFRP와 나선형 철근 록볼트를 사용하여 사면 조건 및 재료 조건에 따른 실험을 수행하고 결과를 비교 검토하였다. 본 연구는 급경사지 및 산사태 위험 지역 등 사면 붕괴 발생 전 조기 감지 및 경보를 통하여 사전에 대피할 수 있는 예 경보시스템 개발 시 기초자료로 활용 될 수 있을 것으로 판단된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.643-650
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• 2004

In general, slope failures are occurred by the interaction among various factors(slope shape, hydraulic condition, and geologic condition, etc.). In the area where has a heavy rainfall, a great portion of slope failures are caused by seepage increasement with suitable failure condition. Many studies have been performed to find the cause of large-scale failures. In this study, three Cut-Slope failures caused by typhoon 'MAEMI' were investigated to find out factors causing large-scale slope failures. It was confirmed in this research that major reason of slope failures was the weak layer working along with other unstable factor. The large-scaled investigation concerning Cut-Slope will be needed to find out the Weak Layer.

• 자원환경지질
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• 제29권5호
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• pp.615-622
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• 1996

Slope stability analysis was conducted using remote sensing and Geoscientific Information System (GIS) as a part of natural hazard assessment around Chungju area. Landsat TM band 5 and 7 which contain more information about geological structure and geography are chosen and processed to analyse regional geological structure. Through image processing technique such as PCA, HFF, edge detection and enhancement, regional lineament can be mapped and identified. The lineament density map is constructed based on summed length of lineaments per unit area and the study area can be divided into 7 structural domains. Various factors of slope stability analysis such as geology, slope aspect, degree of slope, landcover, water shed as well as characterized structural domain are constructed as a database of GIS. Rating and weighting of each factor for slope stability analysis is decided by considering environmental geological characteristics of study area. Spatial analysis of regional slope stability is examined through overlaying technique of the GIS. The result of areal distribution of slope stability shows that the most unstable area is all over Jaeogae-ni, Hyangsan-ni and Mt. Daedun.

• 한국조경학회지
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• 제33권6호
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• pp.127-139
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• 2006

Mt. Yokmang landscape design awarded first in [North container terminal site furtherance construction in Busan new port], design competition sponsoring in the Korea Container Terminal Authority in 2005. Design guideline was to propose the symbol of new port and to establish landscape plan in consideration of view and geological location. Because landscape plan required establishment of restoration plan for cutting slope, Mt. Yokmang became the major object. The purpose of planning are as follows. The first purpose is to minimize existent natural environment damage, and the second, to connect with ambit and create new image. The third is to provide place of rest and interchange for local resident. Reflecting stratum structure and landscape characteristics, cutting slope consisted of [utilization slope], [presentation slope], [landscape slope], and [ecological slope]. Vegetation design applied ecological restoration method through restoration of stratum, and eve environment-friendly afforestation, planned program that can connect area with existing ecosystem. In process that decides form of the cutting slope, analyze view structure and visual exposure in various access routes, sensitivity etc. was accomplished. Also, symbolic tower(Ocean Polaris) that presents in architecture and landscaping features, night landscape planning could gain synergy effect by keeping consistence with landscape and ecological planning. Passing through final design and construction process, I expect that the Mt. Yokmang will be a new landmark in Busan new port.

• 한국재난관리표준학회지
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• 제4권1호
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• pp.67-74
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• 2011

본 연구는 집중호우로 발생한 급경사지 붕괴의 발생원인을 조사 분석하였다. 급경사지 붕괴의 발생원인을 도출하기 위하여 2009년 7월에 발생한 급경사지 붕괴현장에 대한 정밀조사를 시행하였다. 급경사지 붕괴의 직접적인 원인은 우기철 선행강우 이후의 집중호우로 판단되며, 산지배수로, 도수로 등 각종 배수로의 기능상실 및 불량, 비탈면의 풍화토 및 풍화암에 대한 풍화특성을 고려않는 사변설계, 도로에 매설된 우수관의 단면부족, 비탈면내 수목뿌리의 지반 교란, 급경사지의 지형 및 지반상태를 고려하지 않은 보강공법 적용 등이 급경사지 붕괴의 주요 원인으로 분석되었다.

• 지질공학
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• 제31권2호
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• pp.165-178
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• 2021

자연사면을 대상으로 강우에 따른 침투해석 및 사면안정해석을 통하여 사면토층의 흙-함수특성곡선(SWCC) 맞춤계수에 따른 안정성의 영향을 평가하였다. 연구 대상사면의 토질시료를 채취하여 토층의 물리적, 역학적 및 불포화 특성을 실험하였다. 현장조건의 흙-함수특성곡선(SWCC)의 맞춤계수 α 및 n을 변화시켜 침투해석을 통한 포화심도를 산정하였으며, 이를 고려하여 한계평형해석기법을 이용한 사면안정해석을 수행하였다. 강우에 의한 침투해석 결과에 따르면 맞춤계수 α가 감소함에 따라 토층 내 포화심도가 급격하게 증가하며, 전체 토층에 대한 포화시간도 짧아지는 것으로 나타났다. 그리고 포화심도를 고려한 사면안정해석결과에 의하면 맞춤계수 α가 감소함에 따라 사면안전율은 급격하게 감소하지만, 맞춤계수 n을 증가시키더라도 사면안전율의 변화는 매우 작은 것으로 나타났다. 따라서 강우침투로 인한 포화심도와 이를 고려한 사면안정성은 흙-함수특성곡선(SWCC)의 맞춤계수 α에 크게 영향을 받으며, 맞춤계수 n의 영향은 상대적으로 매우 작음을 알 수 있다.

• 한국방재학회 논문집
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• 제10권3호
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• pp.147-154
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• 2010

본 연구에서는 강우에 기인하는 산사태에 의한 토사발생특성을 분석하였다. 이를 위해 1차원 불포화 지하수해석을 수행하여 강우에 따른 토양수분의 거동을 추정하였으며, 무한사면해석법을 이용하여 토양수분상태에 따른 유역단위 사면안정해석을 수행하였다. 이 때, 산사태의 발생 및 파괴깊이에 영향을 주는 토양심 및 여러 식생인자들을 고려하였다. 강우사상의 특성에 따른 토사발생특성 분석 결과, 산사태에 의한 토사의 발생에는 강우강도와 강우의 시간적 군집상태가 결정적인 영향을 미친다는 것을 알 수 있었다. 극치강우에 의한 유역 내 토사발생특성 분석결과, 태풍 '루사' 시의 잔여강우량이 다른 극치사상들에 비하여 매우 크게 나타났으며, 이러한 잔여강우량이 발생된 토사의 운송에 기여하였을 것으로 파악되었다. 아울러, 소수의 극치강우에 의하여 발생한 토사량이 유역 내 전체 토사발생량의 많은 부분을 차지함을 알 수 있었다.

• 한국방재학회 논문집
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• 제9권1호
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• pp.135-144
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• 2009

본 연구에서는 대표단위도가 작성되어 있는 중규모 하천유역을 대상으로 첨두유량을 발생시키는 임계지속기간을 결정하고 임계지속기간과 관련된 수문요소들에 대한 평가를 수행하였다. 임계지속기간과 유역특성인자, 유역응답시간 특성인자 그리고 단위도 특성인자들과의 상관분석을 실시하였다. 분석결과, 재현기간을 제외한 나머지 수문요소(확률강우강도식, 유출량 산정방법, 유효우량 산정방법, 강우시간분포)이 임계지속기간에 영향을 미치는 것으로 판단되었다. 상관분석을 통하여 유역면적, 유로연장, 유로경사, 유역경사가 임계지속기간과 상관성이 높은 것으로 나타났다. 상관성이 높은 유역특성인자와 임계지속기간과의 다중회귀 분석을 실시하고 7가지 형태의 회귀식을 제시하였으며, 유도된 회귀식의 결정계수가 모두 $0.96{\sim}0.97$으로 나타나 매우 높은 상관관계를 갖는 것으로 나타났다.