• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.344-344
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• 2016

최근 도시화에 따른 투수면적의 감소인한 우수 유출량의 증가로 비점오염 및 도시 침수피해에 대한 문제가 증가하고 이에 따른 유역관리에 대한 관심이 높아지고 있다. 불투수면적의 특성으로 인한 도시 비점오염의 축적량 증가와 함께 적은 강우에도 유출이 발생되고 이로 인한 세척효과에 의해 고농도의 비점오염원을 하천으로 유출시키게 된다. 이러한 우수 유출 및 비점오염원 관리방안으로 저영향개발(LID;Low Impact Development) 기법에 의한 우수유출량의 저감과 수질개선효과를 연구할 필요가 있다. 따라서 본 연구에서는 전주시 송천동 지역을 대상으로 관측자료를 이용하여 SWMM모형을 구축하였고, 그 결과를 바탕으로 LID기법 중 하나인 Bioretention과 저류조용량(900, 1050, 1200, $1350m^3$)을 고려한 수질개선 효과를 분석하였다. 송천동 지역에 대한 저류조 및 Bioretention 적용에 따른 수질 개선효과를 비교한 결과 SS는 무시설의 경우 평균 100.08mg/L에서 1) 저류조의 경우 83.40mg/L(17% 감소), 2) 식생저류지의 경우 86.27mg/L(14% 감소), 3) 저류조와 식생저류지 연계 적용의 경우 79.43mg/L(21% 감소)로 평가되었다. BOD는 무시설의 경우 평균 15.24mg/L에서 1) 저류조의 경우 13.37mg/L(12% 감소), 2) 식생 저류지의 경우 12.29mg/L(19% 감소), 3) 저류조와 식생저류지 연계 적용의 경우 11.81mg/L(22% 감소)로 나타났다. T - P는 무시설의 경우 평균 1.09mg/L에서 1) 저류조의 경우 0.96mg/L(12% 감소), 2) 식생저류지의 경우 0.84mg/L(22% 감소), 3) 저류조와 식생저류지 연계 적용의 경우 0.78mg/L(28% 감소)로 수질이 개선되었다. 저류조와 식생저류지 적용에 따른 SS의 경우, 식생저류지를 적용했을 경우보다 저류조를 적용했을 경우 수질농도가 더 많이 저감되는 것으로 산정되었다. BOD와 T - P의 경우 저류조를 적용했을 경우보다 식생저류지를 적용했을 경우 수질농도가 저감 되는 것으로 나타났다. 또한 저류조와 식생저류지를 연계 적용했을 경우 각각 적용했을 경우보다 수질농도가 더 많이 저감되는 것으로 평가되며, 향후 유역 내 LID기법과 저류조 위치에 따른 효과에 대한 연구가 필요하다.

• Journal of Korea Water Resources Association
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• v.35 no.4 s.129
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• pp.359-366
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• 2002

The damages from the natural disasters, especially from the floods, have been increasing. Therefore, it is imperative to establish a BMP to diminish the damages from the floods and to enhance the welfare of the nation. Developed countries have been generating and utilizing flood risk maps to raise the alertness of the residents, and thereby achieving efficient flood management. The major objectives of this research were to develop a prototype management system for flood risk map to forecast the boundaries oi the inundation and to plot them through the integration of geographic and hydrologic database. For more efficient system development, the user requirement analysis was made. The GIS database design was done based on the results from the research work of river information standardization. A GIS database for the study area was built by using topographic information to support the hydrologic modeling. The developed prototype include several modules; river information edition module, map plotting module, and hydrologic modeling support module. Each module enabled the user to edit graphic and attribute data, to analyze and to represent the modeling results visually. Subjects such as utilization of the system and suggestions for future development were discussed.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.2
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• pp.60-68
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• 2008

Three land-use limitations including water hazard, soil erosion and fallow potential were evaluated to define an unfair area. Landscape indices in the unfair areas, defined by evaluations before and after landscape enhancement, were computed by Fragstats v3.3 and compared in order to propose a landscape enhancement plan. The results are as follows: First, as a result of the land evaluation, 388.56ha was analyzed for the 1st class(S1), 623.25ha for the 2nd class(S2), 138.08ha(S3s: 82.47ha, S3e: 51.88ha) for the 3rd class(S3), 230.44ha(N1w: 194.91ha, N1e: 23.09ha, N1es: 13.94ha) for the 4th class(N1), and 67.91ha(N2w: 60. 89ha, N2es: 7.02ha) for the 5th class(N2). The classes under the 3rd class(including the 3rd class) were determined as an unfair area, and proposed landscape enhancement for them. Second, it was proposed that unfair areas with potential water hazards(N1 w, N2w) be restored as a wetland and buffer zone. At this point, the farmers owning these fields could be compensated using the direct payment for landscape conservation(DPLC). Areas witha relatively lower slope(S3e) or a steep slope(N1e) containing soil erodibility potential were proposed to be restored as a sod-culture-applied field and substitute vegetation or potentially natural vegetation, respectively. The unfair areas having fallow potential(S3s, N1es, N2es) were proposed to apply special use crops for the S3s fields, native plants for the N1es fields, and intended fallow for the N2es fields. Third, after landscape enhancement, theforest had higher values in the indices of NP, PLAND, LSI, IJI, and TCA, while paddy and upland had lower values in most indices except NP and LSI. The forest patches increased and were more plentiful with their restoration and had much greater possibility to join with nearby patches. With continued restoration, forest patches will have a large core area and small number of patches due to the conglomeration of patches, which positively influences the species of diversity in the forest patches.

• Journal of the Korean Geographical Society
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• v.41 no.1 s.112
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• pp.106-120
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• 2006

Natural or man-made disaster has been expected to be one of the potential themes that can integrate human geography and physical geography. Typhoons like Rusa and Maemi caused great loss to insurance companies as well as public sectors. We have implemented a natural disaster management system for a private insurance company to produce better estimation of hazards from high wind as well as calculate vulnerability of damage. Climatic gauge sites and addresses of contract's objects were geo-coded and the pressure values along all the typhoon tracks were vectorized into line objects. National GIS topog raphic maps with scale of 1: 5,000 were updated into base maps and digital elevation model with 30 meter space and land cover maps were used for reflecting roughness of land to wind velocity. All the data are converted to grid coverage with $1km{\times}1km$. Vulnerability curve of Munich Re was ad opted, and preprocessor and postprocessor of wind velocity model was implemented. Overlapping the location of contracts on the grid value coverage can show the relative risk, with given scenario. The wind velocities calculated by the model were compared with observed value (average $R^2=0.68$). The calibration of wind speed models was done by dropping two climatic gauge data, which enhanced $R^2$ values. The comparison of calculated loss with actual historical loss of the insurance company showed both underestimation and overestimation. This system enables the company to have quantitative data for optimizing the re-insurance ratio, to have a plan to allocate enterprise resources and to upgrade the international creditability of the company. A flood model, storm surge model and flash flood model are being added, at last, combined disaster vulnerability will be calculated for a total disaster management system.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.529-539
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• 2010

In order to evaluate the effect of soil salinity and culturing conditions including compost application and vinyl mulching on the maintenance of ridge and the growth of upland crops, three crops such as corn, soybean and sweet potato were experimented by using three or four cultivars of crops in the Saemangeum reclaimed tidal land. Average soil salinity before seeding was 2 dS $m^{-1}$, which was low enough for general upland crops to grow. However, high soil EC more than 16 dS $m^{-1}$ was observed in some parts of the experimented field. In the experiment, it was concluded that growth retardation and yield reduction of summer upland crops might be from severe erosion of ridge, soil compaction, flooding or wet soil condition and high salinity of some parts, and then these deteriorations were possibly improved for good crop growth and yield increase by compost application and vinyl mulching cultivation in the Saemangeum reclaimed tidal land.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.617-626
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• 2022

In Korea, annual precipitation and its variability have gradually increased since modern meteorological observations began, and the risk of disasters has also been increasing due to significant regional variations and recent abnormal climate conditions. Given that damage from storms and floods mainly occurs around rivers, it is crucial to determine the appropriate design frequency for river-related projects. This study examined existing design practices used to determine hydrological design frequencies and suggested a new method to determine appropriate design frequencies. The study collected available data pertaining to seven evaluation factors, specifically the basin areas, shape parameters, channel slopes, stream orders, backwater effect reaches, extreme rainfall frequencies, and urbanized flood inundation areasfor 413 local rivers in Chungcheongnam-do in Korea. The estimated weights for areas of extreme rainfall frequencies and urbanized flood inundation were found to be 18, having a great effect on determining the design frequency. Compared with the established design frequency in previous government reports, the estimated design frequency increased for 255 rivers and decreased for 158 rivers.

• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.9-15
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• 2021

The frequency of flash floods in mountainous areas is increasing due to the abnormal weather that occurs increasingly in the recent, and it causes human and material damages is increasing. Various plans for disaster mitigation have been established, but artificial plans such as raising embankment and dredging operation are inappropriate for valleys and rivers in national parks that prioritize nature protection. In this study, flood risk assessment was conducted for Gyeryongsan National Park in Korea using the WMS (Watershed Modeling System)which is rainfall runoff model for valleys and rivers in the catchment. As the result, it was simulated that it is flooding in three sub-catchments (Jusukgol, Sutonggol, Dinghaksa) of a total in Gyeryongsan National Park when rainfall over the 50 years return period occurs, and it was confirmed that the risk of trails and facilities what visitors are using was high. The risk of trails in national parks was quantitatively presented through the results of this study, and we intend to present the safe management guidelines of national parks in the future.

• Journal of the Korean GEO-environmental Society
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• v.14 no.11
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• pp.55-63
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• 2013

Agricultural small dam reservoirs in Korea are vulnerable to flooding because of insufficient flood control capacity and deterioration such that reservoir water level is likely to rise rapidly and a large amount of water release quickly to downstream without flood warning. In this study, we performed hydrologic analysis to estimate design flood(200 years return period ${\times}1.2$) and also evaluated the effect of siphon spillway as a structural countermeasure for flood control and mitigation by applying reservoir routing to the Jipyeong reservoir, located in Sangju, Korea. The results show that the design flood was calculated at $284.3m^3/s$, and water level and water release decreased by 40cm and $91m^3/s$, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.141-150
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• 1992

Rapid change of urban area become a serious cause of disaster in existing drainage systems, and the practical alternatives in that situations are needed. The purpose of this study is to evaluate safety, one of drainage systems, detention reservoir and pumping station by new pumping criteria. New drainage pumping criteria, divided into two parts (rising limb and falling limb), which used in reservoir routing, shows more efficient flood prevention effect than existing criteria (based on the reservoir water level). To obtain the optimal range of flood prevention, sensitivity analysis of each inflow v.s. pumping capacity is tested. As a results, using 10 year design rainfall, 60% of detention reservoir and drainage pumping stations in Seoul are safe. In this results, there must be a fundamental and powerful counterplans to prevent inland flooding in Seoul metropolitan area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.5
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• pp.645-654
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• 2018

Extreme rainfall events caused severe damage to human life and property due to the inundation in major urban areas. In particular, the increase in the intensity of rainfall due to climate change causes changes in the design flood discharge. As a result, it causes uncertainty in the design criteria of hydraulic structures. However, quantitative analysis results have not been provided due to the limitations of climate scenarios and the uncertainty in climate changes. Therefore, this research chose Bulgwangcheon basin as the target basin to analysis the discharge considering climate change. As the result, it is necessary to strengthen design standards since the amount of discharge increased by 14.2% even in the near future.