• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.517-517
• /
• 2017

본 연구는 저수지 주변 생태환경 서식적합도지수를 산정하여 댐 건설 전후의 생태환경을 정량적으로 평가하고자 하였다. 생태적 가치에 대한 평가 모델 고려 인자로는 고도, 경사 및 각과 같은 물리적 요인, 산림 지형, 식생 유형, 연령층, DBH 등급과 같은 초목 요인들, 그리고 생태 자연상태, 식생 보존 분류 및 야생 생물 출현 지점과 같은 서식지 요인을 이용하였다. 각 요소의 생태학적 기능을 고려한 평가기준을 정량화하여 개발된 모델은 한탄강 댐 저수지에 적용하였다. 그 결과 댐 건설 이전의 생태 가치가 100이라고 가정했을 때, 댐 건설 이후에 물리적 요소는 83.9, 초목요소는 92.4, 그리고 서식처 요소는 84.5로 저하되었다. 전반적인 생태 가치는 건설 후 86.9 %, 13.1 % 감소하였다. 또한, 평가 요소를 쌓은 방법을 통해 생태학적으로 건강한 지역을 선정하였다. 본 연구결과는 댐 저수지에 생태 복원 계획을 수립하는 데 유용할 것으로 판단된다.

• Tunnel and Underground Space
• /
• v.13 no.2
• /
• pp.138-152
• /
• 2003

Three-dimensional computer modeling using FLAC3D had been carried out fur evaluating the thermal-mechanical stability of a high-level radioactive waste repository excavated in several hundred deep location. For effective modeling, a FISH program was made and the geological conditions and rock properties achieved from the drilling sites in Kosung and Yusung areas were used. Sensitivity analysis fer the stresses and temperatures from the modeling designed utilizing fractional factorial design was carried out. From the sensitivity analysis, the important design parameters and their interactions could be determined. From this study, it was found that deposition hole spacing is the most important parameter on the thermal and mechanical stability. The second and third most important parameters were disposal tunnel and buffer thickness.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.16 no.1
• /
• pp.11-20
• /
• 2010

Oyster production is playing an important role in domestic aquaculture, but facing some problems such as exports decrease, a slowdown in domestic demand and marine environmental deterioration. In order to obtain the suitable and sustainable oyster production, suitable sites selection is an important step in oyster aquaculture. This study was conducted to identify the suitable sites for lunging culture of oyster using Geographic Information System(GIS)-based multi-criteria evaluation methods. Most of the parameters were extracted by Inverse Distance Weighted(IDW) methods in GIS and eight parameters were grouped into two basic sub-models for oyster aquaculture, namely oyster growth sub-model(Sea Temperature, Salinity, Hydrodynamics, Chlorophyll-a) and environment sub-model(Bottom DO, TOC, Sediment AVS, Benthic Diversity). Suitability scores were ranked on a scale from 1(leased suitable) and 8(most suitable), and about 80.1% of the total potential area had the highest scores 5 and 6. These areas were shown to have the optimum condition for oyster culture in GeojeHansan Bay. This method to identify suitable sites for oyster culture may be used to develop bivalve culture management system for supporting a decision making.

• The Journal of the Korea Contents Association
• /
• v.12 no.8
• /
• pp.388-398
• /
• 2012

In this study, Entropy method and PROMETHEE(Preference Ranking organization METHod for Enrichment Evaluations) which is one of the multi criteria decision making methods are applied to estimate the relative inundation risk ranking of the urban sewer systems. Then, the evaluation factors were selected considering two main items to estimate the inundation risk using Entropy and PROMETHEE. In the first item considering topographical and environmental factor, average elevation, average slope, width of area, population, density of conduit were selected as the detailed factors of first item which have influence of the overflow occurrence and damage scale in urban sewer system. And, the relative reliability of sewer network was considered as the second item which can quantify the inundation appearance. Then, the reliability is estimated considering the number of overflow nodes and overflow volume simultaneously. Therefore, the suggested inundation risk evaluation method can be used as the evaluation index for sewer networks and contribute to decision making for the sewer rehabilitation policy.

• Journal of the Korean Geotechnical Society
• /
• v.37 no.5
• /
• pp.19-31
• /
• 2021

Groundwater level (GWL) causes the stress state within soil and affects the bearing capacity and the settlement of foundation. In this study, the analyses of influencing factors on GWL fluctuation were performed. From the results, river stage and moving average of precipitation were main influence components for urban near large river and rural areas, respectively. In addition, the prediction performance of GWL using artificial neural network (ANN) was conducted with respect to the influence components. As a result, the effect of main component was significant on the prediction performance of GWL.

• Journal of the Korean Geotechnical Society
• /
• v.24 no.8
• /
• pp.81-88
• /
• 2008

In this study, to determine the priority of the effect factors and the preferences of commonly used reinforcing methods for the cut-slope, the reasonable analysis using AHP technique was performed. Analytic Hierarchy Process (AHP) technique is the most widely used method out of all existing decision making methods. On choosing the methods, the most important factor is analyzed to be the stability and durability. Stability, durability and environmental compatibility took up over 50% of the total contributing factors. Cut-slope reinforced method preference with increasing stability method confirmed that concrete retaining wall, reinforced-soil wall and cutting method showed the highest preference rate. Also, in practical field conditions, the cutting method out of four methods was chosen to be the most effective method. This reflected that the methods that are equally superior in all aspects of evaluation factors are more important than the methods with superiority in highly prioritized evaluation factors.

• Journal of Korean Society of Forest Science
• /
• v.103 no.2
• /
• pp.258-263
• /
• 2014

The purpose of this study is to provide basic data for forest roads management by using AHP methodology to group the grade of disaster risk. In addition to this, a field study was performed at 114 targeted points on forest roads where there are high risks of disaster occurrence. The results of the field survey and the analysis of AHP were compared to provide the degree of disaster risks. It shows that the drainage facilities occupied the highest weighted value. Meanwhile, based on AHP analysis data, evaluation chart was created by providing evaluation criteria and evaluation score to each evaluation items. As a result of applying the evaluation chart to the field survey data, the highest score was 78.8 and the lowest score was 42.7 with the mean score of 61.8. Finally, through the experts' consultation based on calculated scores, this study proposed four different groups of disaster risk on forest roads.

• Journal of Wetlands Research
• /
• v.16 no.4
• /
• pp.403-411
• /
• 2014

This study Development of Evaluation Items and Indicators for Hydrological Safety on Agricultural Reservoir improvement and grasped the relative importance through stratification of the evaluation points through AHP technique exercised by group of experts. Below conclusion was acquired based on the study done. Firstly, the hierarchy of the evaluation items was divided into two layers: there were six upper evaluation items and eleven lower evaluation items. Secondly, using the analytic hierarchy process, the importance values of the six upper evaluation items were determined via the paired comparison questionnaire survey and consistency check, which were in the order of maintenance condition (condition evaluation grade), freeboard of levee body (non-overtopping), discharge capacity of spillway, potential flood damage, flood calculation factor and freeboard of downstream bank. The maintenance condition(condition evaluation grade) was significantly influenced the results of the hydrological safety on agricultural reservoir evaluation results. Finally, the study indicated that in the short term, improving the safety check condition evaluation grade will be useful to improve the hydrological safety of the agricultural reservoir because it can be performed immediately.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.460-464
• /
• 2008

본 연구에서는 하천환경의 현재 상태를 진단할 수 있는 하천환경평가기법을 제시하고, 수원천을 평가하였다. 이를 위해 윤세의(2007)가 제시한 도시하천평가기법의 53개 평가항목 중 설문조사의 결과를 이용하여 중요도가 높은 하천환경 관련 항목을 선별하고, 이를 하천환경평가기법의 평가항목으로 사용하였다. 평가항목은 총 27개이고, 평가결과는 총괄지수, 특성지수, 부문지수, 항목지수와 평가등급으로 나타내었다. 수원천의 조사구간은 광교저수지 하류부에서 세류대교까지 약 6.0 km이었고, 총 39개의 구간에 대하여 하천환경평가기법과 도시하천평가기법의 평가지수를 비교하였다. 하천환경평가를 적용한 결과 수원천의 총괄지수는 $2.57{\sim}3.86$으로 나타났고, 하천특성 지수는 $2.20{\sim}2.95$, 생태환경 특성지수는 $1.91{\sim}4.02$로 나타났다. 또한 두 가지 평가기법에 대한 총괄지수와 특성지수의 평균등급은 동일하게 계산되었고, 부문지수 평균등급은 수로, 하상 등의 부문에서 등급변동이 나타났지만 2개 등급 이상의 차이를 보이지 않았다. 이러한 평가결과를 통해 도시하천 평가기법으로부터 파생된 하천환경평가기법의 적용가능성은 확인하였다. 앞으로 많은 대상하천을 선정, 평가를 실시하고, 하천의 연속성과 평가인자들 간의 연계성 등을 반영하는 부분에 대한 연구가 더 필요하다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.36 no.6
• /
• pp.507-514
• /
• 2018

TSI (TPI-Slope Index) which is the combination of TPI (Topographic Position Index) and slope was newly proposed for landslide and applied to a landslide susceptibility model. To do this, we first compared the TPIs with various scale factors and found that TPI350 was the best fit for the study area. TPI350 was combined with slope to create TSI. TSI was evaluated using logistic regression. The evaluation showed that TSI can be used as a landslide factor. Then a logistic regression model was developed to assess the landslide susceptibility by adding other topographic factors, geological factors, and forestial factors. For this, landslide-related factors that can be extracted from DEM (Digital Elevation Model), soil map, and forest type map were collected. We checked these factors and excluded those that were highly correlated with other factors or not significant. After these processes, 8 factors of TSI, elevation, slope length, slope aspect, effective soil depth, tree age, tree density, and tree type were selected to be entered into the regression analysis as independent variables. Three models through three variable selection methods of forward selection, backward elimination, and enter method were built and evaluated. Selected variables in the three models were slightly different, but in common, effective soil depth, tree density, and TSI was most significant.