• Environmental Engineering Research
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• 제23권1호
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• pp.84-91
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• 2018

The present study deals with the management of groundwater resources of an important agriculture track of north-western part of Saudi Arabia. Due to strategic importance of the area efforts have been made to estimate aquifer proneness to attenuate contamination. This includes determining hydrodynamic behavior of the groundwater system. The important parameters of any vulnerability model are geological formations in the region, depth to water levels, soil, rainfall, topography, vadose zone, the drainage network and hydraulic conductivity, land use, hydrochemical data, water discharge, etc. All these parameters have greater control and helps determining response of groundwater system to a possible contaminant threat. A widely used DRASTIC model helps integrate these data layers to estimate vulnerability indices using GIS environment. DRASTIC parameters were assigned appropriate ratings depending upon existing data range and a constant weight factor. Further, land-use pattern map of study area was integrated with vulnerability map to produce pollution risk map. A comparison of DRASTIC model was done with GOD and AVI vulnerability models. Model validation was done with $NO_3$, $SO_4$ and Cl concentrations. These maps help to assess the zones of potential risk of contamination to the groundwater resources.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.459-462
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• 2004

This study assesses groundwater vulnerability to contaminants in 12 administrative districts of the city of Changwon, using DRASTIC technique. DRASTIC was originally applied to situations in which the contamination sources are at the ground surface, and the contaminants flow into the groundwater with infiltration of rainfall. However, groundwater contamination in urban areas can also be related to excessive pumping resulting in a lowering of the water level. The correlation coefficient between minimum DRASTIC indices and the degree of poor water quality for 10 districts is low as 0.40. The correlation coefficients between minimum DRASTIC indices and the groundwater discharge rate, and between minimum DRASTIC indices and well density per unit area are 0.70 and 0.87, respectively. Thus, to evaluate the potential of groundwater contamination in urban areas, it is necessary to consider other factors such as groundwater withdrawal rate and well density per unit area with ratings and weights as well as the existing six DRASTIC factors.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.150-150
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• 2021

Soil erosion due to climate change is one of the global environmental issues. Especially, Korea is vulnerable to soil erosion as the frequency of extreme rainfall events and rainfall intensity are increasing. Soil erosion causes various problems such as reduced farmlands, deterioration of water quality in rivers, etc. To these severe problems, understanding the process of soil erosion is the first process. Then, it is necessary to quantify and analyze soil ersoion using an erosion model. Soil erosion models are divided into empirical, conceptual, and physics-based models according to the structures and characteristics of models. This study used GSSHA (Gridded Surface Subsurface Hydrologic Analysis), the physics-based erosion model, running on WMS (Watershed Modeling System) to analyze soil erosion vulnerability of the CheonCheon watershed. In addition, we compared the six sediment transport capacity formulas provided in the model and evaluated the equations fir on this study site. Therefore, this result can be as a primary tool for soil conservation management.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2004년도 학술발표논문집
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• pp.32-32
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• 2004

• 한국수자원학회논문집
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• 제49권8호
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• pp.685-692
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• 2016

본 연구는 유역의 물이용 취약성을 평가하는 지표 기반 접근법을 개발하고 이를 한강유역의 단위유역에 적용하였다. 평가 지표는 기후뿐만 아니라 사회 경제 환경적 측면을 고려하여 총 16개를 선정하였으며, 취약성 정의에 따라 노출, 민감도, 적응능력으로 구성하였다. 이는 다기준 의사결정기법(Multi-criteria Decision Making, MCDM) 중 TOPSIS (Technique for Order Performance by Similarity to Ideal Solution)를 적용하여 유역에 대한 취약성을 도출하였다. 지표 자료는 2010년을 기준으로 수집하였으며, 국가 통계 자료 및 SWAT (Soil and Water Assessment Tool) 모형의 모의 자료를 활용하였다. 또한, 각 지표에 대한 가중치는 전문가 설문조사를 통하여 산정된 주관적 가중치(Subjective weight)와 자료 기반 엔트로피(Entropy) 개념을 활용하여 산정된 객관적 가중치(Objective weight)로 구분하여 적용하였다. 수도를 포함하고 있는 한강 유역에 대하여 표준단위유역별 취약성을 평가하고 우선순위 비교 및 순위상관 분석을 실시하였다. 취약한 유역들은 대부분 용수사용량이 많고 상수도 누수율이 높게 나타났다. 가중치 적용 방법에 따른 취약성은 일부 지역에서 차이를 보였으나, 전반적으로 북한강유역의 취약성이 가장 높았다. 본 연구 결과를 통하여 보다 신뢰도 높은 물이용 취약성 평가를 위해서는 다양한 가중치 방법론을 활용하는 것이 중요함을 확인할 수 있었다.

• Coupled systems mechanics
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• 제9권4호
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• pp.359-379
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• 2020

Due to susceptibility of bridges in the past earthquakes, vulnerability assessment and strengthening of bridges has gained a particular significance. The objective of the present study is to employ an analytical method for the development of fragility curves, as well as to investigate the effect of strengthening on the RC box-girder bridges. Since fragility curves are used for pre-and post-earthquake planning, this paper has attempted to adopt the most reliable modeling assumptions in order to increase the reliability. Furthermore, to acknowledge the interaction of soil, abutment and pile, the effect of different strengthening methods, such as using steel jacketing and FRP layers, the effect of increase in the bridge pier diameter, and the effect of vertical component of earthquake on the vulnerability of bridges in this study, a three-span RC box-girder bridge was modeled in 9 different cases. Nonlinear dynamic analyses were carried out on the studied bridges subjected to 100 ground motion records via OpenSEES platform. Therefore, the fragility curves were plotted and compared in the four damage states. The results revealed that once the interaction of soil and abutment and the vertical component of the earthquake are accounted for in the calculations, the median fragility is reduced, implying that the bridge becomes more vulnerable. It was also confirmed that steel jackets and FRP layers are suitable methods for pier strengthening which reduces the vulnerability of the bridge.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권spc호
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• pp.92-98
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• 2022

Although various methods have been proposed to assess groundwater vulnerability, most of the models merely consider the mobility of contaminants (i.e., intrinsic vulnerability), and the attenuation capacity of vadose zone is often neglected. This study proposed an evaluation model for the attenuation capacity of vadose zone to supplement the limitations of the existing index method models for assessing groundwater vulnerability. The evaluation equation for quantifying the attenuation capacity was developed from the combined linear regression and weighted scaling methods based on the lab-scale experiments using various vadose zone soils having different physical and biogeochemical properties. The proposed semi-quantifying model is expected to effectively assess the attenuation capacity of vadose zone by identifying the main influencing factors as input parameters together with proper weights derived from the coefficients of the regression results. The subsequent scoring and grading system has great versatility while securing the objectivity by effectively incorporating the experimental results.

• 한국토양비료학회지
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• 제45권5호
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• pp.711-716
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• 2012

기후변화는 100년 후에 남한의 강수량이 17% 증가할 것으로 예측되었다. 우리나라와 같이 여름철 집중호우가 발생하는 경우는 농경지 토양유실이 많아질 것으로 예상된다. 또한 폭풍을 동반한 국지성 호우는 농경지에 많은 피해를 주고 있기 때문에 이에 대한 영향을 최소화하기 위한 적응계획 수립이 시급한 실정이다. 이에 본 연구는 232개 시군구를 대상으로 농경지 토양유실의 취약성 평가를 실시하였다. 취약성 평가의 기간은 현재는 2000년, 미래는 A1B 시나리오를 기준으로 2020년, 2050년, 20100년에 대한 자료를 취합하였다. 취약성을 평가하기 위해 기후노출, 민감도, 적응능력의 대용변수를 선정하였다. 취합된 자료는 표준화 과정을 거쳐 델파이 조사에서 도출된 가중치를 고려하여 취약성을 산정하였다. 취약성은 현재는 남부지방인 제주도와 경상남도가 취약한 것으로 판단되었으나 미래 취약성은 강원도가 증가 추세를 보였다. 본 연구를 통하여 지자체 단위에서 농경지 토양침식에 대한 기후변화 적응계획을 수립하는데 도움이 되고자 한다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.126-128
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• 2003

As a systematic approach to waste disposal site screening for groundwater pollution protection, the DRASTIC system developed by the US Environmental Protection Agency (USEPA) was introduced at Younggwang County in Korea. Hydrogeologic spatial databases for the system include info rmation on depth to water, net recharge, aquifer media, soil media, topographic slope, hydraulic conductivity and lineament. Using the databases, the DRASTIC system and a GIS, the regional groundwater pollution vulnerability of the study area was assessed. The fracture density extracted from lineament maps was added to the DRASTIC system to take into account the preferential migration of contaminants through fractures. From the results of the study, a degree of groundwater pollution vulnerability through the study area was easily interpreted, and waste disposal sites could be screened for groundwater protection.

• 한국산림과학회지
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• 제109권4호
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• pp.446-453
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• 2020

이 연구는 AHP(Analytic Hierarchy Process) 분석기법을 활용하여 사방댐 대상지 선정과 관련된 인자의 중요도를 정량적으로 산정하고, 이를 시범 적용함으로써 사방댐 대상지 선정과 관련된 기초자료를 제시하고자 하였다. AHP 분석을 위해 평가항목 및 평가인자를 구분한 결과 평가항목은 3개(위험성, 취약성 및 시공성), 평가인자는 총 12개(위험성 10개, 취약성 및 시공성 각 1개), 평가기준은 평가인자별 2~6개로 선정되었다. 선정된 평가항목, 평가인자 및 평가기준별 중요도를 활용하여 평가기준별 상대적 중요도를 산출한 결과, 취약성 항목인 의료시설, 노유자시설, 교육시설 및 민가 등이 타 항목보다 높게 나타났다. 사방댐 타당성평가 적격 판정지역의 중요도를 강원도 내 사방댐 미설치유역 24,431개소에 적용한 결과, 사방댐 배치가 가능한 산림유역은 전체 산림유역의 35.2%에 해당하는 8,601개소로 나타났다.