• Parasites, Hosts and Diseases
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• v.26 no.3
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• pp.207-214
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• 1988

The Hongcheon river system knows down through the Hongcheon area of Kangwon-do, and reaches to the Cheongpyeong "Dam in Kyonggi.do. Stool specimens from the inhabitants residing along the Hongcheon river basin were examined to detect infection rates of Metagonimus sp. , and the intermediate hosts were collected to detect larval stages. The results obtained were as follows: 1. Thirty-nine (33 males and 6 females) out of 529 (314 males and 215 females) inhabitants were infected with Metagonimus sp., showing a total positive rate of 7.4%. 2. In eight areas surveyed, the specimens from Kulji.ri of Bukbang-myon at the middle part of the river showed the highest positive rate of 26.9% (14 positives out of 52) (males; 38.2%), The specimens from Mogog-ri of Seo-myon at the downstream of the river showed a positive rate of 10.4%(13 positives out of 125) (males; 12.6%). The positive rates in other regions were less than 10%. 3. The density of the first intermediate host, Semisulcospira sp., was the highest in Kulji.ri of Bukbang-myon (10~20 snails per $m^2$), and the infection rate of Metagonimus cercariae in the snails was 10.7%(13 positives out of 121 snails). 4. The infection rate of Metagonimus metacercariae in Zacco platypus, the freshwater Bish favorably eaten raw by the inhabitants, was 68.25 (30 positives out of 44 fishes), and most metacercariae were detected under the scales (89.95). 5. Adult flukes were obtained from the small intestine of a rat, 15 days after infection with the metacercariae obtained from Z. platypus. These adult cukes were identified to be the same species as thcse obtained from human hosts. By this survey, new endemic areas of Metagonimus infection were discovered along the Hongcheon river basin and the main source of infection was the fresh water ash, Z. platypus.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.348-358
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• 2015

Impacts of climate change are being observed in the globe as well as the Korean peninsula. In the past 100 years, the average temperature of the earth rose about 0.75 degree in celsius, while that of Korean peninsula rose about 1.5 degree in celsius. The fifth Assessment Report of IPCC(Intergovermental Panel on Climate Change) predicts that the water pollution will be aggravated by change of hydrologic extremes such as floods and droughts and increase of water temperature (KMA and MOLIT, 2009). In this study, future runoff was calculated by applying climate change scenario to analyze the future water quality for each targe period (Obs : 2001 ~ 2010, Target I : 2011 ~ 2040, Target II : 2041 ~ 2070, Target III : 2071 ~ 2100) in Hongcheon river basin, Korea. In addition, The future water quality was analyzed by using multiple linear regression analysis and artificial neural networks after flow-duration curve analysis. As the results of future water quality prediction in Hongcheon river basin, we have known that BOD, COD and SS will be increased at the end of 21 century. Therefore, we need consider long-term water and water quality management planning and monitoring for the improvement of water quality in the future. For the prediction of more reliable future water quality, we may need consider various social factors with climate components.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3570-3576
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• 2013

This paper calculated advanced sewage treatment efficiency and reduction pollution loads to estimation contribution ratio of for community sewerage in Hongcheon-gun County. The A2/O and SBR methods showed overall high treatment efficiency of 95% and 94% respectively, and SS was 80%. On the other hand, T-N and T-P showed relatively low processing efficiency of 56% and 60% respectively, but it was observed that SS showed high 96% in the MBR method. Next, by the result of yearly water change analysis on water quality of Hongcheon River which is the discharge river of community sewerage, it was observed that water quality was greatly deteriorated by COD, T-N and T-P. However, installation and operation of community sewerage showed high pollution load reduction in general water quality item by more than 80%, and in T-N and T-P by 58% and 68% respectively. It is expected that community sewerage will greatly contribute in water quality improvement of Hongcheon River.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.29-38
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• 1995

The purpose of this study is to improve the present methodology-for the estimation of optimal water supply from an impounding reservoir. The stochastic reservoir storage model presented in this paper is believed to be rational in that. the probability of reservoir depletion (return period) is to be calculated for the various monthly demands and storage capacities. The monthly flows are used to derive the reservoir storage capacity-monthly demand-probability curves at Dalcheon damsite and Hongcheon damsite in Han river basin.

• KDI Journal of Economic Policy
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• v.44 no.4
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• pp.1-24
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• 2022

We investigate how reforestation contributed to stabilization of riverine water levels in South Korea. For the purpose, we estimate an equation capturing dynamic relationships among rainfall, upstream-area tree stock, and downstream water levels in three river systems of Hongcheon, Mangyeong, and Hyeongsan, using daily observations of precipitation and water levels for the period from 1985 to 2005. Simulation based on estimation results shows that increase in the tree stock in a river basin leads to a significantly suppressed peaking in riverine water levels in response to an abrupt and concentrated rain in the upstream area. For instance, an hour-long concentration of 100mm rain results in 0.7m rise in water level if the volume of growing stock is 1 million m³, whereas the rise in water level stays below 0.27m with 5 million m³ in the growing-stock volume.

• Journal of Wetlands Research
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• v.13 no.1
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• pp.149-160
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• 2011

This study developed a HSI for the creatures in Hongcheon River in order to analyze the conditions proper for habitats. For the index, the investigator identified a total of seven items encompassing hydraulic characteristics such as flow velocity and water depth, and water quality characteristics such as water temperature, BOD, DO, TN, and TP. The subject river was simulated, inspected, and revised with a two-dimensional river model (RMA-2) and water quality model (QUAL2E). Using GIS, the developed index was divided by section by reflecting river characteristics and compared and analyzed with the statistics. The river was divided into a total of 29 reaches by reflecting the basic characteristics and the features of the hydraulic coefficient on the cross-sections of the river. According to the analysis results, the fish scored the highest mean of the overall habitat suitability index of 0.769 at reach 27. Each of the variables had the following mean values: 0.122 m/s for flow velocity, 0.782m for water depth, $14.3^{\circ}C$ for water temperature, 0.68 mg/l for BOD, 10.3 mg/l for DO, 2.4 mg/l for TN, and 0.0121mg/l for TP.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.356-356
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• 2022

최근 기후변화로 인해 여름이면 매번 홍수와 가뭄이 공존하는 특성이 지속되고 있다. 이로 인해 여름이면 태풍, 홍수로 인한 수해재가 증가되고 또한, 가뭄의 지속기간이 길어져 가뭄의 심도가 심화되어 인적, 재산의 피해가 증가되고 있다. 이와 같은 기후변화로 인한 수재해를 예방하기 위해서는 무엇보다도 대상유역의 유역별 강우로 인한 유역 응답 특성을 정량화가 필요하다. 본 연구에서는 유역별 강우로 인한 유역 응답 특성을 정량화하기 위해 홍천강 유역을 연구 대상 유역으로 선정하였다. 홍천강 유역은 한강의 제1지류로서 한강 유역 중앙부에 위치하고 있으며, 하천연장과 유로연장은 106.99 km, 유역면적은 1,566.39 km²로 한강유역 면적의 5.95 %를 차지한다. 본 연구의 목적을 효율적으로 달성하기 위해 홍천강 본류 상·하류 관계에 있는 홍천군(굴운교), 홍천군(홍천교), 홍천강(반곡교) 지점을 연구 대상지점으로 선정하였다. 대상 지점의 유출량은 2021년에 개발된 수위-유량관계곡선식으로 환산하였으며, 유출특성 분석의 적정성은 강우대비 유출률과 상·하류 간 유출 수문곡선으로 평가하였다. 지점별 유역평균강수량을 티센가중법으로 산정하여 상·하류 간 유출 특성을 분석한 결과, 홍천군(굴운교) 35.93%, 홍천군(홍천교) 36.06,% 홍천군(반곡교) 37.25%의 특성을 보였다. 이는 2021년 홍천강 유역의 강수량이 연평균강수량에도 미치지 못한 점을 감안하여 볼 때, 이의 특성은 적정성을 가진 것으로 판단된다. 또한 상·하류 간 첨두 유출량도 상류에서 하류로 갈수록 증가하는 일반적인 양상을 나타내었다.

• Journal of Korea Water Resources Association
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• v.52 no.12
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• pp.1057-1066
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• 2019

The storage function method is used as a flood prediction model for four flood control offices in Korea as a method to analyze the actual rainfall-runoff relationship with non-linearity. It is essential to accurately estimate the parameters of the storage function method for accurate runoff analysis. However, the parameters of the storage function method currently in use are estimated by the empirical formula developed by the limited hydrological analysis in 2012; therefore, they are somewhat inaccurate. The kinematic wave method is a method based on physical variables of watershed and channel and is widely used for rainfall-runoff analysis. By adopting the two-term storage function method by the conversion of the kinematic wave method, parameters can be estimated based on physical variables, which can increase the accuracy of runoff calculation. In this research, the reproducibility of the kinematic wave method by the two-term storage function method was investigated. It is very easy to estimate the parameters because equivalent roughness, which is an important physical variable in watershed runoff, can be easily obtained by using land use and land cover, and the physical variable of channel runoff can be easily obtained from the basic river planning report or topographic map. In addition, this research examined the applicability of the two-term storage function method to runoff simulation of Naechon Stream, a tributary of the Hongcheon River in the Han River basin. As a result, it is considered that more accurate runoff calculation results could be obtained than the existing one-term storage function method. It is expected that the utilization of the storage function method can be increased because the parameters can be easily estimated using physical variables even in unmeasured watersheds and channels.

• Journal of Korea Water Resources Association
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• v.45 no.3
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• pp.301-316
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• 2012

Two models, TANK and SWAT (Soil and Water Assessment Tool) were compared for simulating natural flows in the Paldang Dam upstream areas of the Han River basin in order to understand the limitations of TANK and to review the applicability and capability of SWAT. For comparison, simulation results from the previous research work were used. In the results for the calibrated watersheds (Chungju Dam and Soyanggang Dam), two models provided promising results for forecasting of daily flows with the Nash-Sutcliffe model efficiency of around 0.8. TANK simulated observations during some peak flood seasons better than SWAT, while it showed poor results during dry seasons, especially its simulations did not fall down under a certain value. It can be explained that TANK was calibrated for relatively larger flows than smaller ones. SWAT results showed a relatively good agreement with observed flows except some flood flows, and simulated inflows at the Paldang Dam considering discharges from upper dams coincided with observations with the model efficiency of around 0.9. This accounts for SWAT applicability with higher accuracy in predicting natural flows without dam operation or artificial water uses, and in assessing flow variations before and after dam development. Also, two model results were compared for other watersheds such as Pyeongchang-A, Dalcheon-B, Seomgang-B, Inbuk-A, Hangang-D, and Hongcheon-A to which calibrated TANK parameters were applied. The results were similar to the case of calibrated watersheds, that TANK simulated poor smaller flows except some flood flows and had same problem of keeping on over a certain value in dry seasons. This indicates that TANK application may have fatal uncertainties in estimating low flows used as an important index in water resources planning and management. Therefore, in order to reflect actually complex and complicated physical characteristics of Korean watersheds, and to manage efficiently water resources according to the land use and water use changes with urbanization or climate change in the future, it is necessary to utilize a physically based watershed model like SWAT rather than an existing conceptual lumped model like TANK.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.202-215
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• 2019

This study was conducted to investigate the spawning preference of the Acheilognathinae fishes in relation to the shell size of host mussels after identifying the species of eggs and fries in the host mussel using our recently developed RFLP (Restriction Fragment Length Polymorphism) molecular marker at four sites [Hongcheon Naechoncheon (HN) and Deokchicheon (HD) from the North Han River basin and Jeongseon Goljicheon (JG) and Joyanggang (JJ) from the South Han River] in South Korea during May in each year between 2015 and 2018. The Acheilognathinae fish observed in the studied sites included one species (Acheilognathus signifer) in HN and JG, three species (Rhodeus uyekii, A. signifer, and Acheilognathus yamatsutae) in HD, and two species (A. signifer and Acheilognathus yamatsutae) in JJ, and we collected 982 host mussels (Unio douglasiae sinuolatus) that inhabited in all four sites. Using the RFLP molecular marker, we confirmed 46 eggs and fry of the Acheilognathinae fish (454 A. signifer, 43 Acheilognathus yamatsutae, and 149 Acheilognathus yamatsutae) in Unio douglasiae sinuolatus (N=163; 16.6%). We compare the average shell length, shell height, and shell width of mussels with [presence] eggs/fry and mussels without [absence] eggs/fry to examine the spawning preference according to the size of host mussels in each site. The results show that the shell length (1.98 mm), shell height (0.85 mm), and shell width (0.73 mm) of mussels with the eggs/fry were significantly larger (Mann-Whitney U test, P=0.002; difference=1.98 mm) than those of mussel without eggs/fry in HD where three species cohabitated. Although the shell length, shell height, and shell width of mussels with the eggs/fry were larger also in the other three sites, the difference was not statistically significant. In addition, we analyzed the mean number of spawned eggs and fry of each species and found $9.31{\pm}5.94$ R. uyekii, $2.86{\pm}2.45$ A.signifer, and $2.50{\pm}1.32$ A. yamatsutae. R. uyekii spawned 6.45-6.81 more eggs than A.signifer and A. yamatsutae on average per mussel, and it was statistically significant (Kruskal-Wallis test, P < 0.001). These findings indicate that the three species of Acheilognathinae fish tend to prefer larger mussels as their spawning hosts, and this tendency increases when the number of cohabitating bitterling fish species increases. Moreover, A.signifer and A. yamatsutae spawned a smaller number of eggs evenly in more host mussels while R. uyekii spawned many eggs on relatively fewer mussels. We found mussels (N=4) having the eggs/fry of two coexisting species, A. signifier and A. yamatsutae in HD and JJ where more than two bitterling fish species occurred. It suggests the interspecific competition taking place between the Acheilognathinae fishes for utilizing the same resource of mussels for spawning when two or more species cohabitate. This study is expected help to understand better the spawning patterns and reproductive ecology of the Acheilognathinae fishes, which will provide insightful information for advancing our understanding of their ecological relationships - mutualism or host-parasitism - with host mussels.