• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.292-292
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• 2018

2016년 태풍 "차바"로 인한 부산과 울산지역의 침수 및 2003년 발생한 태풍 "매미"로 인한 마산창원지역의 침수사례는 우리나라 해안도시유역이 해수면 상승에 의한 피해에 노출되어 있음을 간접적으로 입증하는 대표적 사례라 할 수 있다. IPCC 4차 평가보고서에 따르면 전 지구적 차원에서 지난 100년 동안 해수면은 약 1.7 m 상승하였으며, 1961~2003년 사이 해수면 상승률은 연평균 3.1 mm에 이르고 있다. 특히 우리나라 남해안은 연평균 3.4 mm씩 상승하고 있어 전 세계 해수면 평균 상승속도를 상회하고 있다. 또한 1990년대 이전보다 이후 기간에 우리나라에 영향을 준 태풍의 수가 많으며 평균적으로 태풍의 강도 및 해일고가 증가하고 있다. 따라서 전 지구적 해수면 상승과 태풍해일고 증가에 따른 복합적인 해수면 상승으로 인한 해안유역의 침수피해가 증가할 것으로 예상되며 특히 미래 발생 가능한 수퍼태풍에 의한 급격한 해일고의 상승은 해안유역에 침수피해를 더욱 가중시킬 것이라 예상된다. 특히 해수면 상승으로 인한 침수피해 특성은 홍수유출에 의한 내륙 침수피해와는 다른 특성을 보이고 있어 이에 대한 대응기법 개발이 절실한 실정이다. 따라서 본 연구에서는 해수면 상승에 따른 해안도시지역 대한 침수피해 예방 및 저감을 위한 침수모의기법을 개발하고 효율적 대응방안을 선정하는 기법을 제안하였다. 부정류 특성을 지닌 해수면 상승 경계조건 및 건물 간 도로를 통해 흐름이 발생하는 특성을 고려하여 해안지역의 시공적 침수규모 및 유속 등을 예측할 수 있는 2차원 수치모형을 개발하였다. 2003년 발생한 태풍 "매미" 발생 기간 동안 관측된 실제 해일고를 적용하여 창원 등 해안도시유역에 범람모의를 수행하였으며 실제 침수흔적과 비교함으로써 모형을 검증하였다. 또한 해안 경계선을 따라 월파방지벽을 설치하는 경계조건을 도입하여 월파방지벽 높이에 따른 해안도시유역 침수규모를 산정하여 월파방지벽 높이에 따른 시공적 침수규모를 분석함으로써 월파방지벽의 효과를 확인하였다. 본 연구결과는 해안지역 지점별 침수규모 및 최대 침수심 발생시간을 제공함으로써 침수에 따른 중장기적 구조적 대응방안 수립은 물론 초단기적 예상 해수면 상승에 다른 대피경로 제공 등 비구조적 수재해 대응 기법을 제시하는 기초자료를 제공에 활용 할 수 있을 것으로 기대된다.

• Journal of Wetlands Research
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• v.18 no.1
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• pp.24-31
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• 2016

The increase of impervious area in cities caused the unbalanced water cycle system and the accumulated various contaminants, which make troubles as introducing into watershed. In Korea, most of rainfall in a year precipitate in a summer season. This indicate that non-point source pollution control should be more important in summer and careful rainfall reuse strategy is necessary. Accordingly, the aim of this study is to monitor the characteristics of rainfall contaminants harvested in roofs and to develop the rainfall treatment system which are designed to fit well in a typical domestic household including rain garden. The rain garden consists of peatmoss, gravel and san to specially treat the initial rainfall contaminants. For this purpose, lab scale experiments with synthetic rainfall had been conducted to optimize the removal efficiency of TN, TP and CODcr. After lab scale experiments, field scale rainfall treatment system installed as a pilot scale in a field. This system has been monitored during June to July in 2015 in four time rainfall events as investigating the function of time, rainfall, and pollutant concentrations. As results, high loading of pollutants were introduced to the rainfall treatment system and its removal efficiency is increased as increase of pollutant concentrations. Since it is common that the mega-size of rainfall treatment system is not attractive in urban area, small scale rainfall treatment system is promising to treat the non-point source contaminants from cities. In addition, this small scale rainfall treatment system could have a potential to water resue system in islands, which usually suffer the shortage of water.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.89-95
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• 2020

Livestock facilities in Korea are on their way of enlargement resulting in increment of livestock manure. When the livestock manure treated inappropriate way during application to the agricultural area, environmental damage can be occurred such as bad smell, water and air pollution. Therefore it is important to make a good management plan for livestock manure treatment. In order to effectively apply organic fertilizer made by livestock manure in terms of quantity and quality, the current status of nutrient in agricultural land should be calculated quantitatively by scientific way. The OECD suggest member countries to calculate the nutrient balance as an agricultural environment indicator which represents the difference between nutrient inputs and outputs of the amount of nutrients in various ways. In this paper, we calculated the nutrient balances according to three cities which have different characteristics such as urban or rural areas. To reduce the nutrient balance, we considered how to reduce the amount of chemical fertilizer by using organic fertilizer made by livestock manure. And public treatment facilities for livestock manure can be a good solution except civil complaints for location selection. Among the options, manure fertilizer application to the agricultural area for cultivation of forage crops was mainly considered to reduce the nutrient balance by decreasing input of chemical fertilizers and increasing output of crop production. Using the field monitoring data, it can be calculated that the daily nitrogen reductions by 116.5 kg/ha and the daily phosphorus increments by 2.7 kg/ha.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.139-147
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• 2021

Livestock manure is used as an organic fertilizer to replace chemical fertilizers after sufficient fermentation in an aerobic bioreactor. On the other hand, liquid manure disposal problems occur repeatedly because soil spraying is restricted during the summer when the crops are growing. To use liquid fertilizer (LF) as an additional nutrient source for crops, it is necessary to reduce the amount of suspended solids (SS) in the liquid fertilizer and secure stability problems against pathogenic microorganisms. This study examined the effects of the simultaneous SS removal and E.coli sterilization in the LF using the microbubble (MB) generator (FeMgO catalyst insertion). The remaining SS were further removed using the integrated microbubble and microfilter system. During the floating process in the MB device, the SS were removed by 57.9%, and the coliform group was not detected (16,200→0 MPN/100 mL). By optimizing the HRT of the integrated system, the removal efficiency of the SS was improved by 92.9% under the 0.1h of HRT condition. After checking the properties of the treated LF, 64.5%, 70.1%, 54.9%, and 51.5% of the TCOD, SCOD, PO4-P, and TN, respectively, were removed. The treated effluent from such an integrated system has a lower SS content than that of the existing LF and does not contain coliforms; therefore, it can be used directly as an additional fertilizer.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.472-487
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• 2020

With the emergence of abnormal climate due to the rapid industrialization, the importance of water quality management and management costs are increasing every year. In Korea, for the management of total phosphorus and total nitrogen, the major materials causing the water quality pollution, coagulants are injected in sewage treatment plants to process organic compounds. However, if the coagulant is injected in an excessive amount to PAC (Poly Aluminium Chloride), a secondary pollution problem might occur. As such, a study on the applicability of natural material-based coagulant is being conducted in Korea. Thus, this study aimed to evaluate the applicability of a mixed coagulant developed by analyzing water quality pollutants T-P, T-N as well as their turbidity, in order to derive the optimum mixing ratio between PAC and torrefied wood flour for the primary settling pond effluent. Under the condition where the content of PAC (10%) and torrefied wood flour is 1%, T-P showed the maximum removal efficiency of 92%, and T-N showed approximately 22%. This indicates that removal of T-N which includes numerous positively charged organic compounds that are equivalent to mixed coagulant is not well accomplished. Turbidity showed the removal efficiency of approximately 91%. As such, 1% of torrefied wood flour was determined to be the optimum addition. As a result of analyzing the removal efficiency for organic compounds by reducing PAC concentration to 7%, T-P showed a high maximum removal efficiency of 91%, T-N showed 32%, and turbidity showed the maximum of 90%. In addition, a coagulation process is performed by using the mixed coagulant based on 1% content of torrefied wood flour produced in this study by performing a coagulation performance comparative experiment with PAC (10%). As a result, PAC concentration was reduced to 30-50%, a similar performance with other coagulants in market was secured, PAC injection amount was reduced that an economic effect can be achieved, and it is considered to perform a stable water treatment that reduces the secondary pollution problem.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.38-44
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• 2015

In Korea, most rainfall events occur during summer which then leads to an increasing concern regarding high influx of non-point source pollutants since the pollutant loadings from these non-point sources are very significant. In particular, the first flush of roof-harvested rainfall is said to contain the most highest concentration of nutrients and heavy metals. Accordingly, it is important to develope the possible water quality management options in treating the contaminants and considering reclaimed water reuse. The rain garden could be one of suitable alternatives in addressing this issue. In this study, the development of an effective adsorption media and its application to a lab-scale rain garden was tested to evaluate the removal rate of various nutrient and organic matter (TN, TP, CODcr), and heavy metals (Cu, Cd, Pb). Results showed that carbonized peatmoss produced at higher temperature have better adsorption capacity as compared to the one produced at a lower temperature. When the carbonized peatmoss was applied as rain garden media, the highest removal of TN, TP, and CODcr was observed compared to no carbonized peatmoss applied rain garden. Therefore, this study showed that the carbonized peatmoss would be effectively applied to the rain garden for removing nutrients and heavy metals from roof-harvested rainwater.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.60-60
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• 2023

태풍 힌남노에 경주에 위치한 총저수량 184만m³, 유역면적 22km²인 왕신저수지는 303m의 제체가 2시간여 동안 전면 월류하는 초유의 사태를 겪었다. 그때 다행히 저수지 수위는 10분 단위로 기록됐다. 이 자료를 이용하여 제체 월류현상을 평가하기 위해 저수지 운영의 기본자료인 유입량, 저수량, 방류량 등을 10분 단위로 생산코자 했다. 방법은 인근에 위치하고 운영자료가 있는 총저수량 260만m³, 유역면적 3.7km²인 감포댐에 대해 유입량 모의방법을 검증하고, 왕신저수지에 그대로 적용하여 유입량을 모의하고, 물수지에 의해 방류량을 계산하는 것으로 했다. 모의결과는 저수량 오차로 신뢰도를 확인했다. 여기서 저수지 유입량은 ONE 모형을 이용하여 10분 단위로 생산했다. 2022년 9월 5일부터 6일까지 10분 단위로 모의한 결과는 다음과 같다. 첫째, 감포댐 유역은 강우량은 10분 최대 32.3mm, 총강우량 196.0mm였고, 유입량은 10분 최대 80.1m³/s, 총유입량 59만m³로 모의됐고, 신뢰도는 RMSE 2.120mm, NSE 0.947, R²는 0.949로 매우 높게 나타났다. 그리고 저수량 모의 신뢰도도 RMSE 0.153m, NSE 0.993, R²는 0.997로 높았다. 둘째, 왕신저수지 유역은 강우량은 유역내에 위치한 환경부 관리의 화산리 관측소에서 10분 최대 21.0mm, 총강우량은 10시간 동안 422.0mm였고, 유입량은 10분 최대 716.5m³/s, 총유입량 904만m³로 모의됐고, 유출률은 95.7%로 강우량 거의가 유입되는 것으로 나타났다. 셋째, 왕신 저수지의 방류량은 10분 최대 610.8m³/s, 총방류량 848만m³로 계산됐고, 총유입량의 93.8%에 상당한 것으로 나타났다. 그리고 저수지 물수지에 의해 10분 단위 모의 저수위의 신뢰도는 RMSE 0.117m, NSE 0.994, R²는 0.999로 매우 높게 나타났다. 넷째, 왕신저수지의 제체고 EL.59.20m를 월류한 시간은 9월6일 5시50분부터 8시까지 2시간10분 동안였으며, 관측 저수위는 EL59.24m~EL.60.28m, 모의 저수위는 EL.59.31m~EL.60.29m로 나타났다. 월류되는 동안 총유입량은 544만m³, 총방류량은 527만m³로 나타나, 유입량의 96.8%가 월류되는 것으로 계산돼 저수지의 저류효과는 거의 없는 것으로 나타났다. 이때 유입량은 전기간의 60.2%, 방류량은 62.1%에 상당했다. 다섯째, 힌남노에 따른 왕신저수지의 홍수조절효과는 첨두유입량을 105.7m³/s 저감시켰고, 홍수량을 56만m³을 저류시킨 것으로 분석됐다.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.667-673
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• 2011

There is relatively high vulnerability of soil erosion in slope highland agriculture due to a reclamation of mountain as well as low surface covering in early summer season with high rainfall intensity time. The aim of this study was to evaluate various surface covering methods for reducing soil loss in highland radish cultivation in highland. The experiment was conducted in 17% sloped lysimeter ($2.5m{\times}13.4m$) with 8 treatments including covering with cut rye, sod culture of rye, Ligularia fischeri var. spiciformis Nakai, Arachniodes aristata Tindale, Aster koraiensis Nakai, Festuca myuros L. and mulching with black polyethylene film, and runoff water, eroded soil and radish growth were investigated. Surface covering with sod culture and plant residue, especially cut rye treatment, had lower runoff water than non-covering, whereas black polyethylene film mulching had the reverse. The amount of eroded soil was also lowest in cut rye treatment, $0.3Mg\;ha^{-1}$, and increased in the order of rye sod culture, Ligularia fischeri var. spiciformis Nakai, Aster koraiensis Nakai, Festuca myuros L., Arachniodes aristata Tindale, black polyethylene film, and non-covering, $68.2Mg\;ha^{-1}$. The results showed that surface covering with sod culture or plant residue could be effective for reducing runoff water and soil erosion in the radish field, significantly in cut rye treatment. On the other hand, in sod culture of rye, Aster koraiensis Nakai and Ligularia fischeri var. spiciformis Nakai, radish yields were lower than in the non-covering. Unlike this, covering with cut rye, sod culture of Festuca myuros L. had similar radish yield to the non-covering radish yield. In conclusion, covering with cut rye and sod culture of Festuca myuros L. were beneficial for reduction of soil loss without decreasing in radish yield in highland sloped fields.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.137-145
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• 2008

In this study, to reduce the flood damage caused by flood discharge exceeding project flood, the primary technology was applied to determining the optimal location and size for underground sluiceway. The Jungrang Stream was selected for this study because the stream was overflowed and the embankment section of the stream was destroyed owing to localized torrential rainfall in 1998 and 2001. Considering 200-year frequency storm, the inlets of the underground discharge channel were located at Seoul City limits, the confluence of Danghyun Stream, Wolgye 1-gyo, and the confluence of Mukdong Stream. The outlets were located at the estuary of Jungrang Stream and rightbank of Banpo Bridge in Han River. The transverse discharge according to the variation of overflow depth at the inlet of underground discharge channel was estimated and the effect of inundation reduction was analyzed. To examine the appropriate scale of the underground discharge channel, the 8 operation methods for the management of outlet discharge were compared considering four rules (only storage, the constant discharge rate, the constant discharge volume, and the mixture of the constant discharge rate and discharge volume). As a result, the effect of inundation reduction was most significantly improved when the inlet was located at the confluence of Danghyun Stream. The appropriate size of underground sluiceway for 200-year frequency storm was studied, and as a result, the appropriate diameters of the underground discharge channel were 12 m in case of only storage(Rule D), 9m in 50% of discharge(Rule E), 8 m in constant discharge volume(Rule F), and 7 m in mixture method(Rule G). This investigation process can be applied to design the underground discharge channel when the inundation damage is significant in coastal area due to embankment overflow. The underground discharge channel in Jungrang Stream can also be used as an underground road to link Seoul City to Uijeongbu City during dry season.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.970-976
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• 2011

Strip tiller equipment was developed to reduce soil erosion in the slope land for highland agricultural area. The equipment consisted of 4 rows strip tillage device and fertilizer applicator. The field was tilled in 10 cm width and in 10 cm depth by the equipment, of which tilled surface was 16.7% of full-width tillage. The working time and fuel consumption of the equipment were $3.8hours\;ha^{-1}$ and $24.4L\;ha^{-1}$ respectively, which were 59% and 74% less than those of the conventional tillage. Fertilizer efficiency of the equipment in cultivation of Chinese cabbage was 1.7, 1.6 and 1.5 times higher in nitrate, phosphorous and potassium respectively, than conventional tillage. When the equipment was used after covering of rye residue, the quantity of runoff was 49~67% lower than the conventional tillage. And the quantity of soil loss were 1.3 and $0.2Mg\;ha^{-1}$ at right after and 30 days after planting of Chinese cabbage respectively, while 11.5 and $4.1Mg\;ha^{-1}$ in conventional tillage. In conclusion, the strip tillage equipment developed in this study can be applicable to slope land, so that soil loss of 90% can be reduced.