• 한국환경과학회지
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• 제24권4호
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• pp.505-514
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• 2015

The grid-based water balance of watershed scale was assessed in the mountainous area of Pyosun catchment in Jeju Island after analyzing precipitation, evapotranspiration, and runoff from January 2008 to December 2013. The existing results of direct runoff, evapotranspirtion, and groundwater recharge comparing to precipitation were presented 22.0%, 25.6%, and 52.4%, respectively, in Pyosun catchment. However, this study indicated each component shows 14.5%, 24.2%, and 61.0%, respectively, in the mountainous area of Pyosun catchment. Therefore, groundwater recharge rate in the mountainous area appears higher than 10% comparing to the overall catchment. It would be analyzed that the amount of direct runoff is relatively small. Moreover, this difference could be generated because of the spatial discontinuities in the process of estimating the total amount of precipitation in the mountainous area. Therefore, the grid-based spatial analysis to maximize the spatial continuity would be useful for providing a more reasonable result when the total amount of water resources are evaluated in mountainous areas in the future.

• 한국물환경학회지
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• 제23권6호
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• pp.872-880
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• 2007

For effective management of sediment-related diffuse pollution, it is of utmost importance to estimate spatial variation of sediment transport processes within a catchment. A mathematical model can play a critical role in estimating sediment transport processes at the catchment scale provided that the model structure is appropriate for representing major sediment transport processes of the catchment of interest. This paper introduces a distributed catchment model River Basin Water Quality Simulator (RBWQS) and presents some results of its application to a small rural catchment in Korea. The model has been calibrated and validated for a wet period using hourly hydrographs and sediment concentrations observed at the catchment outlet. Based on the model simulation results, the spatial variation of sediment transport processes across the catchment and the effects of paddy fields and small reservoirs on hydrology and sediment transport have been analyzed at the catchment scale.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.253-257
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• 2007

Channel-aquifer interaction is one of the key hydrological processes that determine water flows in the stream/river channel. Field measurements of channel-aquifer interaction, however, is very difficult and costly, particularly when one intends to understand its variations across a catchment for a long period. Hydrological simulations using a catchment model are a relatively easier and cheaper alternative provided the model structure is appropriate for describing channel-aquifer interaction. In this study, a catchment model called CAMEL (Chemicals from Agricultural Management and Erosion Losses) is used for estimating channel-aquifer interaction over time and space. CAMEL is a distributed catchment model to simulate transformation and transport processes of sediment and pollutants as well as water flows at the catchment scale. In the model, a catchment is represented using a network of square columns each of which is comprised of various storages of water. CAMEL explicitly simulates both surface and subsurface processes including channel-aquifer interaction. This paper presents an application study results of CAMEL for the Tarland Burn Catchment, a small (catchment area $52\;km^2$) rural catchment in Scotland, UK, demonstrating some of the channel-aquifer interaction dynamics across the catchment during a 2-year period.

• 한국물환경학회지
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• 제27권4호
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• pp.475-485
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• 2011

Lake Sihwa has a very unique watershed environment, surrounded by industrial, urban and rural catchment area with different land use. The first flush phenomenon was investigated in 3 catchment area. 4TG, representing the industrial area, shows rapid discharges of highly concentrated pollutants during the early stages of a storm and it is indicating a strong first flush effect. At AS, representing the urban area, the pollutant concentration reached its peak approximately 2~3 hours after the start of storm, which is a strong first flush effect did not appear. JJB and MS represent the rural areas, the PEMC analysis results suggest that highly concentrated pollutants were discharged during the middle and latter stages of a storm, instead of early pollutant runoff due to the effects of rainwater runoff.

• 한국지역지리학회지
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• 제23권2호
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• pp.388-402
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• 2017

본 연구는 중력모델 기반의 접근도 분석 모델을 수정 보완하여 연령별 응급의료 서비스의 접근도를 분석한 내용이다. 보건의료 접근도 분석에 적용되고 있는 Two-Step Floating Catchment Area(2SFCA) 모델을 보완하여 임계거리 차별화, 거리조락 반영, 연령별 응급의료 이용가중치, 관내 응급의료기관 선택가중치 등을 반영하였다. 개선된 접근도 모델(Modified Three-Step Floating Catchment Area model, M3SFCA)을 통해 충청남도 응급의료기관의 공간적 접근성 분석을 하였다. 분석 결과는 다음과 같다. 첫째, 유소년층, 청장년층, 노년층 모두 응급의료기관을 중심으로 접근성이 높고, 임계거리가 중첩되는 지역에서 접근성이 높았다. 둘째, 시군 연령별 공간적 접근성은 연령대별로 지역차가 뚜렷하며, 전반적으로 북부지역이 남부지역보다 접근성이 높게 나타났다. 셋째, 연령별로 접근성 차이가 발생한 이유는 연령별 임계거리, 응급의료기관 이용비중, 관내 기관 이용비중이 각각 다르며, 연령별 총 인구수의 차이로 나타났다. 마지막으로 본 연구는 응급의료 접근도 모델 개선을 통해 이론적 연구를 통한 실제 현장의 활용성의 가능성과 잠재성을 확인하였다. 연구 결과를 바탕으로 보건의료 및 응급의료 관련 정책 개발 및 활용에 기여할 것으로 기대한다.

• 한국농공학회논문집
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• 제62권6호
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• pp.111-118
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• 2020

This study developed a rainwater harvesting system for the irrigation of upland on sloping area. The assessment of water supply capacity was evaluated in farm field experience. This system consists of a water catchment device and a collapsible storage tank. The water catchment device was designed to collect runoff water in natural channel of 500 mm width into a pipe of 50 mm inner diameter. The device has funnel-shaped plan and cross-section of square. The storage capacity of the collapsible water tank was caculated to meet the water demand for irrigation in 30 a cultivated land for 10-year frequancy drought. The tank has a cuboid shape with a capacity of 30 ㎥, 5 m in width and length, 1.2 m in height. This system can supply 92% of the water required for drop irrigation of red pepper and 88% of the water required for drop irrigation of onions in 30 a cultivation land during the month of May and June. In the case of 16-dry days of 10-years frequency, this system is capable to irrigate 100% of required water for red pepper and onion, 76.7% of required water for Omija (Schisandra chinensis), and 51.5% of required water for autumn kimchi cabbage.

• 보건행정학회지
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• 제18권4호
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• pp.66-84
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• 2008

Objectives: This study aimed to. offer some fundamental evidences for the stroke management policy by investigating the trends of medical care utilization and regionalization in stroke inpatients. Methods: We used the National Health Insurance claims and registry data for stroke inpatients from 1998 to 2005. Among all stroke inpatient claims data, self-employed insured and their dependents were only included in this study. The classification of stroke was based on ICD-10(I60-I69) and its subtype was divided by hemorrhage(I60-I62) and infarction(I63-I64) type. To evaluate regionalization of medical care utilization, relevance index was calculated by regions. The regions were classified 8 large catchment areas and 163 self authorized areas. Results: The overall medical care utilization rate of stroke inpatient has been increased, especially infarction subtype. Among medical care institutions, the utilization of hospital has been the most rapidly increased. Although considered annual rate of interest, total medical cost of stroke inpatients has been increased, Totally, more than 84% of stroke inpatient were admitted to medical care institutions in their own large catchment area during 1998-2005. The relevance indices in their own large catchment area (self sufficiency rates) were more than 70% in most areas regardless of stroke subtype except Chungbuk catchment area. Self sufficiency rates of stroke inpatients among 163 self authorized areas in 1998 and 2005 were 84.2% and 83.1% in metropolitan, 46.7% and 45.5% in urban, and 19.5% and 22.6% in rural areas, respectively. Conclusion: Stroke management policy for improvement of distribution at the district level, especially in rural areas, may be helpful for reducing regional inequality in stroke.

• 한국물환경학회지
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• 제24권1호
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• pp.69-77
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• 2008

This study was conducted to know the characteristics of agricultural non-point source pollutants runoff by rainfall events at the upper catchment of Goseong reservoir in Gonjy city, Chungnam Province. For this study, the monitoring sites of the research catchment were set nineteen during the research period (between June 2005 and October 2006). Average runoff coefficient were observed 0.51 in 2005, 0.71 in 2006, respectively. The correlation coefficient (r) between the rainfall and peak-flow was investigated 0.787. By rainfall events, the water quality of the sites were shown like this : BOD 0.555~9.60 mg/L, T-N 0.01~13.50 mg/L, T-P 0.002~2.952 mg/L, and SS N.D~820.0 mg/L. The strong rainfall intensity was the most important factor of the soil erosion. The gabs of the arithmetic mean concentrations and the flow weighted mean concentrations were observed as the followings : BOD 0.0~29.2%, T-N 0.1~11.4%, T-P 0.4~95.2%, and SS 1.7~57.0% in 2005, and BOD 1.0~11.9%, T-N 0.7~7.3%, T-P 9.9~36.5%, and SS 6.6~36.5% in 2006, respectively. The BOD pollution load was 2,117 kg (36% of the total BOD loading of survey periods) while, T-N was 3,209.0 kg (27.9% of the total T-N loading of survey periods), T-P was 136.4 kg (37.4% of the total T-P loading of survey periods) and SS was 72,733.8 kg (51.8% of the total SS loading of survey periods) in the year 2005. In case of 2006, BOD load was 1,321.7, T-N was 2,845.8, T-P was 42.9, and SS was 16,275.8 kg, respectively.

• 한국농공학회논문집
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• 제54권1호
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• pp.27-38
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• 2012

This study is to analyse the hydrological behavior of agricultural reservoir using CAT (Catchment hydrologic cycle Assessment Tool). The CAT is a water cycle analysis model in order to quantitatively assess the characteristics of the short/long-term changes in watershed. It supports the effective design of water cycle improvement facilities by supplementing the strengths and weaknesses of existing conceptual parameter-based lumped hydrologic models and physical parameter-based distributed hydrologic models. The CAT especially supports the analysis of runoff processes in paddy fields and reservoirs. To evaluate the impact of agricultural reservoir operation and irrigation water supply on long-term rainfall-runoff process, the CAT was applied to Idong experimental catchment, operated for research on the rural catchment characteristics and accumulated long term data by hydrological observation equipments since 2000. From the results of the main control points, Idong, Yongdeok and Misan reservoirs, the daily water levels of those points are consistent well with observed water levels, and the Nash-Sutcliffe model efficiencies were 0.32~0.89 (2001~2007) and correlation coefficients were 0.73~0.98.

• 한국농공학회논문집
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• 제57권1호
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• pp.89-97
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• 2015

This study is to assess the effect of non-point source pollution discharge loads between tillage and no-tillage applications for upland crop areas using SWAT (Soil and Water Assessment Tool) watershed modeling. For Byulmi-cheon small rural catchment ($1.17km^2$) located in upstream of Gyeongan-cheon watershed, the rainfall, discharge and stream water quality have been monitored in the catchment outlet since 2011. The SWAT model was calibrated and validated in hourly basis using 19 rainfall events during 2011-2013. The average Nash-Sutcliffe model efficiency and $R^2$ (determination coefficient) for streamflow were 0.67 and 0.79 respectively. Using the 10 % surface runoff reduction from experiment results for no-tillage condition in field plots of 3 % and 8 % slopes under sesami cultivation, the soil saturated hydraulic conductivity for upland crop areas was adjusted from 0.001 mm/hr to 0.0025 mm/hr in average. Under the condition, the catchment sediment, T-N (total nitrogen, TN), and T-P (total phosphorus, TP) discharge loads were reduced by 6.9 %, 7.4 %, and 7.7 % respectively.