• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.151-164
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• 2013

Multidimensional dynamic water quality model of organic matter and trophic state was applied to the Han River system. The model was calibrated using field measurement data obtained during the year of 2007. The model results showed reasonable performance in predicting temporal variations of TN, TP, Chl-a and BOD concentrations. The applied integrated modeling system can be effectively used to simulate water quality as well as hydrodynamic and water temperature for river-lake continuous system in the Han River. Utilizing the calibrated model, we analyzed the spatial and temporal distributions of TN, TP, Chl-a and BOD concentrations in the Han River system. The temporal variations of water quality at each river reach and lake were effectively simulated with the developed model and spatial distribution of water qualities in the Han River system could be compared. The multidimensional dynamic modeling system can simulate the water qualities of entire waterbody where Lake Paldang and the incoming flows are included using single modeling system. So it can be effectively used for integrated water quality management of the Han River system.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.141-141
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• 2015

IPCC 5차 보고서에서 기술되어 있는 것처럼 기후시스템의 온난화는 명백하며, 1950년 이후 관측된 많은 변화들은 지난 수천 년간 전례가 없는 것이었다. 지구 온난화로 대표되는 기후변화는 이제 일부 국가에 국한되는 문제가 아니라 전 지구적인 문제가 되었다. RCP 시나리오에 따라 차이는 있으나 대한민국의 경우 연평균 강수 총량은 증가할 것이라 예상되는 반면 총 예상 강우 일수는 감소하여 집중호우의 발생빈도가 증가될 것이라 예상되고 있다. 이에 따라 수자원의 효율적 이용에 대한 필요성 또한 증가하고 있는 실정이다. 본 연구에서는 수자원의 효율적 이용을 위해 한강수계 9개 댐(화천, 춘천, 소양강, 의암, 청평, 충주, 괴산, 횡성, 팔당)을 대상으로 HEC-ResPRM과 선형계획법을 이용하여 발전량을 최적화 하였다. HEC-ResPRM은 미공병단 수문공학센터에서 개발한 저수지운영 최적화 모형으로 홍수 조절, 관개, 발전, 레크리에이션 등 다양한 요구조건을 만족시킬 수 있는 최적의 저수지 운영방안 도출이 가능하다. 본 연구에서는 HEC-ResPRM 모형과 선형계획법을 이용한 운형모형의 결과자료를 비교하였으며 이를 통해 HEC-ResPRM 모형의 특징과 활용 가능성을 확인하였다.

• Ecology and Resilient Infrastructure
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• v.9 no.1
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• pp.1-14
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• 2022

The total maximum daily load (TMDL) implemented in Korea mainly manages the mainstream considering a single common pollutant and river discharge, and the river system is divided into unit watersheds. Changes in the water quality of managed rivers owing to the water quality management in tributaries and unit watersheds are not considered when implementing the TMDL. In addition, it is difficult to consider the difference in the load of pollutants generated in the tributary depending on the conditions of the water quality change in each unit watershed, even if the target water quality was maintained in the managed water system. Therefore, it is necessary to introduce the total maximum load management at tributaries to manage the pollution load of tributaries with a high degree of pollution. In this study, the HSPF model, a watershed runoff model, was applied to the target areas consisting of 53 sub-watersheds to analyze the effect of water quality changes the in tributaries on the mainstream. Sub-watersheds were selected from the three major areas of the Paldang water system, including the drainage basins of the downstream of the South Han-River, Gyeongan stream, and North Han-River. As a result, BOD ranged from 0.17 mg/L to 4.30 mg/L, and was generally high in tributaries and decreased in the downstream watershed. TP ranged from 0.02 mg/L - 0.22 mg/L, and the watersheds that had a large impact on urbanization and livestock industry were high, and the North Han-River basin was generally low. In addition, a pollution source reduction scenario was selected to analyze the change in water quality by the amount of pollution load discharged at each unit watershed. The reduction rate of BOD and TP according to the scenario changes was simulated higher in the watershed of the downstream of the North Han-River and downstream and midstream of the Gyeongan stream. It was found that the benefits of water quality reduction from each sub-watershed efforts to improve water quality are greatest in the middle and downstream of each main stream, and it is judged that it can be served as basic data for the management of total tributaries.

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.439-448
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• 2007

The purpose of this study was to investigate the seasonal variations of sediment oxygen demand (SOD) in Lake Paldang and Lake Chungju of the Han River system and to suggest SOD values as parameters for the water quality prediction models of two lakes. SOD was measured at laboratory using sediment collected at 2 sites in Lake Paldang from June to November and at 4 sites in Lake Chungju from May to November in 2005, respectively. It was found from the laboratory test that the SOD in Lake Paldang ranged from 337.8 to 881.0 mg $O_2m^{-2}d^{-1}$ and in Lake Chungju ranged from 143.0 to 969.1 mg $O_2m^{-2}d^{-1}$. The SOD of Lake Paldang showed similar variations to the content of organic matter of sediment. The SOD of Lake Chungju was positively correlated with temperature (r=0.78, p<0.01), $PO_4-P(r=0.79,\;p<0.01)$, TP (r=0.55, p<0.05), DTP (r=0.55, p<0.05), $NO_3-N$ (r=(0.72, p<0.01) of hypolimnetic water. These results indicate that the SOD of Lake Paldang was affected by the content and origin of organic matter of sediment and the SOD of Lake Chungju was closely correlated with physical and chemical factors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1334-1343
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• 2008

Growing needs for efficient management of water resources urge the joint operation of dams and integrated management of whole basin. As one of the tools for supporting above tasks, this study aims to constitute a hydrologic model that can simulate the streamflow discharges at some control points located both upper and down stream of dams. One of the currently available models is being studied to be applied with a least effort in order to support the ongoing project of KWATER (Korea Water Resources Corporation), "Establishment of integrated operation scheme for the dams in Han River Basin". On this study, following works have been carried out : division of Han River Basin into 24 sub-basins, use of rainfall data of 151 stations to make spatial distribution of rainfall, selection of control points such as Soyanggang Dam, Chungju Dam, Chungju Release Control Dam, Heongseong Dam, Hwachun Dam, Chuncheon Dam, Uiam Dam, Cheongpyung Dam and Paldang Dam, selection of SSARR (Streamflow Synthesis and Reservoir Regulation) model as a hydrologic model, preparation of input data of SSARR model, sensitivity analysis of parameter using hydrologic data of 2002. The sensitivity analysis showed that soil moisture index versus runoff percent (SMI-ROP), baseflow infiltration index versus baseflow percent (BII-BFP) and surface-subsurface separation (S-SS) parameters are higher sensitive parameters to the simulation result.

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.93-98
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• 1993

To investigate the organic matter transformation in aquatic environment, seasonal fluctuations of heterotrophic activity and microbia] extracellular enzyme activity were studied in Paldang Lake, Korea. The turnover time in the water column and the sediment at the station I fluctuated between 3 -I ,300 hrs and 17-170 hrs for glucose, 5 -1.900 hrs and 15-240 hrs for protein hydrolysate and 4-350 hrs and 15-230 hrs for acetic acid, respectively, indicating that the seasonal turnover time of organic substrates fluctuated drastically. The respiration ratios of glucose. protein hydrolysate and acetate were 23-32%, 38-41% and 22-28% in the water column and 34%, 61% and 41% in the sediment. respectively. These results showed that the respiration ratios in the sediment were higher than those in the water column regardless of kinds of organic substrates. The bacterial extracellular enzyme activities of $\alpha$-glucosidase. $\beta$-glucosidase, N-acetyl-$\beta$-D-glucosaminidase and aminopeptidase were 32-44%. 31-32%, 18-34% and 61-67% in the water column, and 34%. 40%, 23% and 65% in the sediment. respectively.

• Korean Journal of Ichthyology
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• v.24 no.4
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• pp.278-286
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• 2012

This study was examined for information of management of bluegill, Lepomis macrochirus which is disturbance species of underwater ecosystem in Korea. Research of bluegill population was investigated spring-summer and autumn periods in the Han river system from 2009 to 2012. Bluegill inhabited mostly lakes, and restrictedly lived at still area in downstream. The range of relative abundance were 0.2~18.2% in individual number and 0.2~40.0% in biomass and it was subdominant or superiority species for the most part of the lakes. Population structure were analyzed r-strategy in Lake Soyang and Paldang and K-strategy in Lake Uiam and Cheongpyeong. But Lake Chungju was estimated transition period from K-strategy to r-strategy. Condition factor and body weight-total length relations were presented favorable condition. For the nesting, bluegill was formatted the group. And the water depth and the distance from shore were mean 56.3 cm and 191.9 cm respectively in nesting ground. Diameter and depth of nests were mean 42.4 cm and 9.7 cm respectively. These results are available for research of population dynamics and reproductive ecology of bluegill.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.85-92
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• 2006

To evaluate the primary production and nutrient uptake of macrophytes in Lake Paldang, this study investigate the vegetation areas of six dominant aquatic plants including Typha angustifolia, Zizania latifolia, Phragmites australis, Trapa japonica, Nelumbo nucifera and Savinia natans, and contents of carbon, nitrogen and phosphorus of each macrophyte. Total vegetation area of six dominant aquatic plants was 1.37 $km^2$. Among them, Typha angustifolia was the most wide-distributed species which occupied the 46.7% of total vegetation area. Littoral zone of South Han river had the largest vegetation area with 0.458 $km^2$, and North Han river, Kyungan river and confluence area in the order named. The results of the contents of carbon, nitrogen and phosphorus of macrophytes showed that the carbon contents of emergent macrophytes was higher than that of other life-forms. The nitrogen content of Salvinia natans, free-floating macrophyte was highest and that of Typha angustifolia, emergent macrophyte was lowest. The phosphorus content of Trapa japonica showed the highest content of phosphorus among six macrophytes and emergent macrophytes such as Zizania latifolia and Phragmites australis showed lower contents of phosphorus than other life-forms. The annual net primary production of macrophytes in Lake Paldang, 2004, was calculated as 758.4 ton C $yr^{-1}$ and the annual net nitrogen and phosphorus uptake of macrophyte was 16,921 kg $yr^{-1}$ and 1,841.0 kg P $yr^{-1}$ respectively. Comparing the total budget of organic carbon, nitrogen and phosphorus in Lake Paldang, the amount of primary production and nutrient uptake by macrophytes take a small portion in total budget implying macrophytes do not play an important role in budget of matters in river-type lake, Lake Paldang.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.978-988
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• 2005

A three-dimensional dynamic model was applied to Lake Paldang, Han River in this study. The model was calibrated and verified using the data measured under different ambient conditions. The model results were in reasonable agreements with the field measurements in both calibration and verification. Utilizing the validated model, we analyzed the spatial and temporal distributions of temperature, current, residence time, and spreading pattern of incoming flows within the lake. Relatively low velocity and high temperature were computed at the surface layer in the southern region of the Sonae island. The longest residence time within the lake was predicted in the southern region of the Sonae island and the downstream region of the South Branch. This can be attributed to the fact that the back currents caused by the dam blocking occur mainly in these regions. Vertical thermal profiles indicated that the thermal stratifications would be occurred feebly in early summer and winter. During early spring and fall, it appeared that there would be no discernible differences at the vertical temperature profiles in the entire lake. The vertical overturns, however, do not occur during these periods due to an influence of high discharge flows from the dam. During midsummer monsoon season with high precipitation, the thermal stratification was disrupted by high incoming flow rates and discharges from the dam and very short residence time was resulted in the entire lake. In this circulation patterns, the plume of the Kyoungan stream with smallest flow rate and higher water temperature tends to travel downstream horizontally along the eastern shore of the south island and vertically at the top surface layer. The model results suggest that the Paldang lake should be a highly hydrodynamic water body with large spatial and temporal variations.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.781-784
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• 2008

현재 한강수계에서는 북한강 상류에 건설된 임남댐(저수용량 26억$m^3$)으로 인하여 화천댐 상류 유역계의 변화가 발생하였다. 화천댐의 경우, 기존의 발전용량을 포함한 안정적 방류계획에 변화가 발생하여 기존 저수지 용량의 효율적인 관리기술의 실증이 필요한 시점이다. 또한, 향후 기후변화 및 용수이용 증가에 대비한 안정적인 물공급을 위해 하천유출량의 시 공간적인 평가 및 가용수자원의 평가는 보다 합리적이고 정확하게 이루어져야 하며, 이를 위해 준분포형 유역유출-저수지 운영 결합해석 모형이 필수적으로 도입되어야 할 시점이다. 따라서, 본 연구에서는 SWAT-K(과학기술부, 2007)를 이용하여 기존댐의 최적 운영룰을 도출한 후, 팔당호에서의 유황개선 효과를 정량적으로 분석하여 수자원 확보량을 평가하고자 하였다. 화천댐의 경우, 방류시나리오로 기존 운영실적을 기준으로 홍수기 중 9월 방류량을 50% 감소, 비홍수기 중 $11{\sim}3$월 방류량을 50% 증가시켜 적용하였을 때 최적 운영룰이 도출되었으며, 이때 갈수량 이하의 10일간 유황개선을 통하여 분석기간에 대하여 0.12억$m^3$의 수자원 확보가 이루어질 수 있었다.