• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.58-58
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• 2020

최근 급속한 지하공간의 개발로 인해 도로함몰 등 지반침하가 지속적으로 발생되어 이에 대한 안전문제가 끊임없이 제기됨에 따라, 원인규명 및 대책방안을 두고 다양한 조사 및 연구가 진행되고 있다. 특히 지하개발 시 필연적으로 발생하는 유출지하수 내 지하수와 함께 토사가 유출될 경우 지반함몰이나 붕괴로 이어져 대규모 재해가 발생할 수 있기 때문에 현장에서 계측되는 데이터를 통해 사전에 지반침하를 감지할 수 있는 경보 시스템이 마련될 필요가 있으며, 이에 대한 기술개발과 관리기준의 변화가 필요하다. 본 연구에서는 현재 지하공간 개발 시 적용되는 지하수 관리 매뉴얼 중 가장 중요한 부분인 계측관리 부분에 관해 문제점을 분석하고 이를 보완하기 위한 계측 관리 및 행정 절차의 문제점을 개선하고자 한다. 지중에서 발생하는 토립자의 이동, 공동발생 및 지반함몰의 거동은 근본적으로 지하수의 이동에 의해 필연적으로 발생되며, 그 규모는 유출지하수량의 발생규모와 상관성이 높게 분석되었다. 계측 관리의 문제를 보완하기 위하여 첫 번째로 지중 굴착 시 계측되는 유출지하수와 지하수위를 연계하여 분석하여 기준을 마련하였고, 추가로 지하수 내 탁도 값을 측정하여 이를 더하여 서로간 상관성 분석을 통해 기존 지하수위 계측자료의 관리기준을 보완하였으며, 최종적으로 현장에서의 계측된 데이터를 통해 지반침하를 사전에 예측할 수 있다. 계측된 데이터의 분석결과 위험도가 감지될 경우 공동발생의 방지 및 복구에 관한 방안이 제시되며, 문제 발생 지점의 범위를 국한하여 신속하고, 경제적으로 해결해 나갈 수 있다. 이를 위해 현행 지하수법의 개선과 행정적 절차가 보완되어야 할 필요가 있다. 이러한 지하공간 개발 시 지하수 관리의 개선으로 사전에 지반침하를 예측 할 수 있고, 이를 통해 재해를 미연에 방지할 뿐만 아니라 건설산업 현장의 스마트 관리체계를 구성하여 미래 지향적인 토목현장 및 국민에 대한 신뢰도를 재고 할 수 있을 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.78-78
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• 2022

농가인구의 감소 및 고령화, 고소득 작물 재배, 기후변화 등으로 인해 영농형태가 논농사에서 밭농사로 전환되고 지역별 증감의 차이가 있기는 하나 밭 면적이 증가하는 추세를 보인다. 한편, 밭작물은 논에 비해 기반시설이 부족하고 고소득의 밭작물을 생산하기 위한 시설재배가 늘어나면서 대부분 사계절 확보가 용이하고 수질이 양호한 지하수를 사용하고 있다. 지하수 수요 증가는 지하수위 저하와 지하수 고갈의 우려를 초래하고 있다. 본 연구에서는 농업용 지하수 이용 실태를 분석하고 지하수이용 및 관리 제도 현황을 검토하여 지속가능한 밭용수 공급을 위한 지하수 관리전략을 제안하였다. 진주시를 대상으로 경지유형에 따른 지하수 이용 특성 분석하여 지하수의 수요 특성을 살펴보았는데, 하천 주변 저지대에 큰규모의 밭이나 집단화된 시설재배 지역이 분포하고 있고 지하수 관정도 밀집하고 있었다. 하천에서 떨어진 산간지역에는 지하수 관정이 산발적으로 분포하고 있었다. 지하수 수요는 공간적 위치 외에도 고품질 농업용수에 대한 요구도 원인인 것으로 조사되었다. 밭기반 용수공급 관련 사업과 지하수 자원확보 관련 법제도 등을 고찰하여 밭의 위치, 규모, 용수공급의 수요 특성 등을 고려하여 밭용수 공급을 위한 세 가지 지하수 관리전략을 제안하였다. 우선, 농업용 지하수 이용량 실측 및 정보의 다각화를 통한 정보의 고도화가 필요하다. 둘째, 지하수 이용의 공간적 특성을 고려하여 지표수와 연계한 지하수 이용기반이 구축되어야 한다. 지표수 공급이 가능한 지역은 지표수를 우선 공급하거나 지하수와 혼합 또는 교차하여 공급하고 물공급 취약지역에서는 지하수 공급 기반시설을 구축하는 것이다. 세 번째 전략은 농업용 지하수 시설의 공공관리 강화 및 관리 효율화이다. 특히 지하수이용이 밀집한 지역에서는 지하수 인허가 기준을 강화하고 용도별 관리체계 구축이 필요하다. 밭용수 공급은 농가 소득과 밀접한 연관이 있기 때문에 물이용의 지속가능성과 함께 농가 소득증대를 고려하는 공편인적 관점에서의 관리가 필요할 것으로 생각된다.

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.127-145
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• 1998

Unlike water or air quality standards that have been established by legislation using potential human health impact as the primary criterion, soil quality depends on the soils primary function and its relevant environmental factors, which is much more site- and soil specific. A properly characterized soil quality assessment system should serve as an indicator of the soil capacity to produce safe and nutritious food, to enhance human and animal health, and to overcome degrative processes. For our proposed example, a high quality soil with regard to maintaining an adequate soil productivity as a food production resources must accommodate soil and water properties, food chain, sustainability and utilization, environment, and profitability, that (i) facilitate water transfer and absorption, (ii) sustain plant growth, (iii) resist physical degradation of soil, (iv) produce a safe food resources, (v) cost-effective agricultural management. Possible soil quality indicators are identified at several levels within the framework for each of these functions. Each indicator is assigned a priority or weight that reflects its relative importance using a multi-objective approach based on principles of systems to be considered. To do this, individual scoring system is differentiated by the several levels from low to very high category or point scoring ranging from 0 to 10, And then weights are multiplied and products are summed to provide an overall soil quality rating based on several physical and chemical indicators. Tlne framework and procedure in developing the soil quality assessment are determined by using information collected from an alternative and conventional farm practices in the regions. The use of an expanded framework for assessing effects of other processes, management practices, or policy issues on soil quality is also considered. To develop one possible form for a soil quality index, we should permit coupling the soil characteristics with assessment system based on soil properties and incoming and resident chemicals. The purpose of this paper is to discuss approaches to defining and assessing soil quality and to suggest the factors to be considered.

• Journal of Soil and Groundwater Environment
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• v.13 no.2
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• pp.44-53
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• 2008

The efficiences of mineral acid (HCl), neutral salts ($CaCl_2$), and chelating agent (citric acid and $Na_2$-EDTA) were tested for extracting heavy metals from open burning and open detonation (OBOD) site soil. The extraction efficiencies of Cd, Cu, Pb and Zn from soil for various extractants were in the order of HCl > citric acid > $Na_2$-EDTA > $CaCl_2$, HCl (1.0 M) extracted effectively 82%, 86%, 80%, and 46% of initial total concentrations of Cd, Cu, Pb, and Zn, respectively. Significant negative correlations were observed between pH of extractant and amount of extracted heavy metals. Initially, examined heavy metals were predominantly bound to carbonate and Fe, Mn-oxide fraction. Though the significant amount of carbonate and Fe, Mn-oxide bounded metals were removed but a significant amount remained metals shifted to exchangeable (more mobile) fraction by HCl and citric acid extraction. The increased mobility of remaining metals could be problematic for water resources, thus careful management is needed to control the movement of heavy metals.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.2
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• pp.63-73
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• 2020

Drought is considered as a devastating hazard that causes serious agricultural, ecological and socio-economic impacts worldwide. Fundamentally, the drought can be defined as temporarily different levels of inadequate precipitation, soil moisture, and water supply relative to the long-term average conditions. From no unified definition of droughts, droughts have been divided into different severity level, i.e., moderate drought, severe drought, extreme drought and exceptional drought. The drought severity classification defined the ranges for each indicator for each dryness level. Because the ranges of the various indicators often don't coincide, the final drought category tends to be based on what the majority of the indicators show and on local observations. Evaporative Stress Index (ESI), a satellite-based drought index using the ratio of potential and actual evaporation, is being used as a index of the droughts occurring rapidly in a short period of time from studies showing a more sensitive and fast response to drought compared to Standardized Precipitation Index (SPI), and Palmer Drought Severity Index (PDSI). However, ESI is difficult to provide an objective drought assessment because it does not have clear drought severity classification criteria. In this study, U.S. Drought Monitor (USDM), the standard for drought determination used in the United States, was applied to ESI, and the Percentile method was used to classify drought categories by severity. Regarding the actual 2017 drought event in South Korea, we compare the spatial distribution of drought area and understand the USDM-based ESI by comparing the results of Standardized Groundwater level Index (SGI) and drought impact information. These results demonstrated that the USDM-based ESI could be an effective tool to provide objective drought conditions to inform management decisions for drought policy.

• Journal of Environmental Impact Assessment
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• v.16 no.2
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• pp.143-156
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• 2007

This study has researched the management status and the pollution level of water, soil, stream sediments of 11 abandoned coal mines out of a total of 12 within Obong-Dam area except Bukyung mine, which was submerged when constructing Obong-Dam, and selected areas which are in needs to have pollution control facilities in the first place. From the results of examination on the runoff at the waste rock pile and mineheads, the runoff from Sueun mine (pH, Fe, Al), Samwon mine (pH, Al), Wangdo mine (pH, Al), Mose mine (pH, Fe, Al) and Daeryeong mine (pH) exceeded the permissible discharge standards of the water quality, but the water at merging point with Obong-Dam after joined with Doma branch satisfied both Water Quality Standards and Drinking Water Quality Standards. In regard to groundwater contamination, it is found that areas where exceeded the Drinking Water Quality Standards are Wangdo mine (pH), Jangjae mine (pH, Zn), Daeryeong mine (pH) whereas all areas satisfied Soil Contamination Warning Standards of Soil Environmental Conservation Law. When comparing a research result on underwater sediments of branches of abandoned mines to the EPA Guidelines for classification of great lakes harbor sediments, Dongguk Gaerim (Fe), Jungwon mine (Fe), Daebo mine (Mn), Samwon mine (Mn) and Daeryeong mine (Mn) showed mid-level of contamination, whereas Sueun (Fe, Mn), Daebo mine (Fe), Woosung mine (Fe, Mn), Wangdo mine (Fe, Mn), Mose mine (Fe) and Daeryeong mine (Fe) showed high-level of contamination. In addition, contamination levels of underwater sediments in Wangsan and Doma branch where abandoned mine's branches merge together, Wangsan branch showed no contamination at all whereas Doma branch shows mid-level of contamination which reflect the Doma branch is affected by waste rock pile and minehead runoff of the abandoned mines in the Doma branch area. It is concluded that Mose mine and Sueun mine required treatment of acid mine drainage. and Wangdo, Jungwon, and Samwon mines were in need of mine tailing and erosion control work. The Samwon mine additionally required a control system for closed minehead runoff. Although the Samwon mine reached a high concentration of Al, Mn $Ca^{2+}$, $SO{_4}^{2-}$ in the runoff, the levels decreased after it was combined with a tributary. It has been concluded that after further monitoring of the cause of pollution, a preventive measure system may be needed to be built.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.282-282
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• 2020

본 연구는 여수시 농어촌지역에 대하여 지하수 함양특성, 개발가능량 산정 및 오염부하량 등의 조사를 통해서 체계적인 지하수자원의 보전관리(안)을 수립하기 위해 수행되었다. 연구지역은 여수시 화양면, 소라면 2개 면을 포함하는 농어촌 용수구역(여소지구)으로, 여소지구의 총면적은 130.68 ㎢이며, 이 중 임야면적은 81.57 ㎢, 경지면적은 32.98 ㎢ 이고, 경지면적은 논 15.37 ㎢, 밭 17.42 ㎢, 시설재배 0.19 ㎢로 구성되어 있다. 여소지구의 30년 강수평균은 1,454.08 mm/년이며, 지하수 함양량은 국가지하수관리 기본계획(국토교통부, 2019) 및 전라남도 지하수관리계획(전라남도, 2009) 보고서를 참고하여 평균값인 11.28%로 산정한 결과, 21,279 천㎥/년으로 분석되었다. 또한, 지하수연보(국토교통부, 2018)의 세부용도별 이용량을 활용하여 지하수 이용량을 산정한 결과, 2,638.35 천㎥/년이었으며, 강수량, 함양률 및 면적 값을 고려하여 지하수 개발가능량을 산정한 결과, 16,387.57 천㎥/년, 개발가능량 대비 이용량은 16.11%로 확인되었다. 여소지구의 질산성질소 항목은 총 181개소(경지면적 0.2 ㎢당 1점)에 대해 분석한 결과, 전체 평균값은 6.67 mg/L이었으며, 농업용수 수질기준(20 mg/L)을 초과한 관정은 8개소(6%)로 확인되었다. DRASTIC을 이용한 오염취약성 지수는 평균값이 119.57점으로 나타나 오염취약성이 낮은 것으로 분석되었다. 신고·허가된 축사 시설을 기준으로 점오염원 조사결과, 단위면적당 시설수(오염원밀도)는 3.12 개소/㎢로 조사되었으며, 인구, 가축 및 토지이용 등 인자별을 고려하여 오염부하량을 산출한 결과, 단위면적당 오염부하량은 75.30 kg/day/㎢로 확인되었다. 행정구역별로 7가지 지표를 반영하여 관심, 주의, 경계 및 심각 4단계로 기준을 설정하여 지하수관리 필요지역을 선정하였다. 수량 측면은 개발가능량 대비 이용량, 단위면적당 이용량 및 관정밀 3가지 지표를 적용하였고, 수질 측면은 질산성질소 평균, 오염취약성 지수, 오염원밀도 및 단위면적당 오염부하량 4가지 지표를 적용하여 선정하였다. 지하수관리 필요지역을 분석한 결과, 전체 18개 리 중에서 14개 리에서 수량관리 12개리에서 수질관리 필요지역이 나타났다. 수량관리 필요지역은 지하수 취수량 조정 및 관리 확충 등의 대책방안이 마련되어야 하며, 수질관리 필요지역은 주변 오염원관리 및 수질검사 강화 등의 대책방안이 필요할 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.815-820
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• 2015

For the establishment of effective water resources management platform for Jeju-Island, the characteristics, including surface runoff, evapotranspiration, groundwater recharge and discharge are to be properly quantified. Among these hydrologic components, interception due to vegetation is very important factor but it is hard to be quantified. After Von Hoyningen-Huene (1981) found the relationship between LAI (Leaf Area Index) and interception storage, LAI has been used for key factor to estimate interception and transpiration. In this study the equation suggested by Kozak et al. (2007) is implemented in SWAT-K (Soil and Water Assessment Tool - Korea) model and is tested at the Cheonmicheon watershed in Jeju-Island. The evaporation due to interception was estimated as 85~104mm, 8~11% of whole evaporation. Therefore it is necessary to consider the evaporation due to interception as a controlling factor to water budget of this watershed.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.89-103
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• 2009

The Philippines is abundant with rich natural resources such as water. Because of rapid urbanization in the country, most of the water bodies are polluted as a result of domestic, agricultural and industrial activities. The Environmental Management Bureau (EMB) is the main government arm responsible for monitoring and inspection of affected water bodies. Only water bodies with at least four sampling events during dry and wet seasons were included in the assessment of water bodies that passed the DAO 90-34 water quality criteria. Water bodies were monitored for dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS), and total dissolved solids (TDS), heavy metals, fecal coliform contamination and nitrates. High pollutant concentrations from domestic, agricultural, industrial and nonpoint sources were observed from monitoring events due to inadequate sewage services and treatment facilities in the country. The objective of this paper was to present and evaluate the quality of the water bodies in the Philippines.

• Water for future
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• v.24 no.1
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• pp.119-128
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• 1991

This study was focused on establishing the concepts of the instream flow to prevent the problems for the conceptual ambiguity and the difference in the instream flow estimation methods. The average drought flow is defined as the flow required to guarantee the minimum function of the river such as prevention of drying. The environmental control flow is defined as the flow required to control optimal river environment, the flow required for navigation, prevention of sea water-intrusion, protection of river management facilities, conservation of water Quality, fishing, prevention of river mouth closure, control of groundwater level, protection of animals and plants, and landscape. The average drought flow was obtained by flow duration analysis for the natural flows in the Han River at Indo-Bridge gaging station. When considering the 9 factors related to environment conservation, the conservation of water quality was proved to be most important. The pollutants for the river flows were estimated and the water qualities were forecasted. After comparing the water qualities in the future and water quality standards, there quired optimal dilution flow was estimated. The average drought flow and environmental control flow are all non-consumptive flows. Therefore larger flow between them, i.e., Max. (average drought flow, environmental control flow) can be the instream flow. The river management flow can be added to the flows for water utilization in the downstream. The results from this study are expected to be very helpful in the systematic river management on the other main rivers in Korea.