• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.465-465
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• 2022

하천 미세플라스틱 측량을 위해 많은 연구자들이 노력하고 있으나 모든 하천에서의 미세플라스틱 실측은 현실적으로 어렵다. 미세플라스틱의 물 환경에 대한 영향을 이해하고 예측하기 위해서는 오염원과 오염원 운송 매개체로서 물 환경에 존재하는 플라스틱의 물리적 거동을 아는 것이 매우 중요하다. 따라서 미세플라스틱의 하천 내 물리적 거동을 과학적으로 규명하고 하천 미세플라스틱오염을 예측가능한 물리모형의 도출이 요구된다. 본 연구에서는 물리기반 하천수질모형인 Water Quality Analysis Simulation Program(WASP8)의 Advanced Eutrophication Module을 이용하여 상용 수질 물리모형의 하천에서의 미세플라스틱 거동 모의 가능성을 검토하였다. 이를 위해 미세플라스틱과 유사한 거동을 보이는 수질지표를 대리인자로 하여 기존에 알려져 있는 물리모형(WASP8의 Advanced Eutrophication Module)을 이용해 미세플라스틱의 하천 내 거동을 설명하고 예측 가능한 모델을 개발하고자 한다. 본 연구결과로부터 하천 미세플라스틱 오염 분석 및 예측의 기초자료를 마련한다.

• Journal of Environmental Impact Assessment
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• v.19 no.5
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• pp.465-473
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• 2010

This study was carried out to investigate the effect of EFDC hydrodynamic result on the WASP7.3 water quality modeling result in accordance with the change of number of grid for the dam reservoir to be constructed. The simulated flow and BOD, T-N and T-P loads by the HSPF watershed model was used for boundary conditions and the hydrodynamic modeling results was linked with WASP model to predict future water quality after dam construction. The scenarios for EFDC modeling were composed of Scenario 1(141 grid cells) and Scenario 2(568 grid cells). The results of Scenario 2 showed that BOD, T-N, T-P and Chl-a concentrations were decreased 0.073mg/L(8.5%), 0.032mg/L(2.6%), 0.003mg/L(6.8%), 0.644mg/L(4.2%) compared with those of Scenario 1, respectively. As number of grid cell increased, water quality concentrations were decreased and also it caused the longer running time. Therefore, this study suggests that the consideration of the geometry of water body is more important than the number of grid cells for the prediction of water quality of a dam reservoir in EIA.

• The Korean Journal of Zoology
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• v.8 no.2
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• pp.15-18
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• 1965

Fatty acid components of the Chestnut gall wasp (Dryocosmus kuriphilus YASUMATSU) were analyzed by the method of gas chromatogrphy at various developmental stages. 1. The fatty acids identified at each stage are as follows : Larva stage : acetic acid , benzoic acid and capric acid. Prepupa stage : acetic acid, benzoic acid and capric acid. Pupa stage : acetic acid, benzoic acid and capric acid. 2. Through the development of the wasp, there were large amount of acetic acid.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.7-18
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• 2008

The objective of this study was to develop and apply a water quality simulation model for the evaluation of ungaged watershed. The Modified WASP5 consisted of three sub-models, LOAD-M, DYN-M, and EUT-M. LOAD-M, an empirical model, estimates runoff loadings using point and non-point source data of villages. Daecheong Dam watershed was selected for the research to calibrate, verify and application of Modified-WASP5. LOAD-M model was established using field data collected from all items of water quality and water quantity gaging stations of the watersheds, and was applied to the ungauged watersheds, taking the watershed properties under consideration. The result of water quality simulation using ModifiedWASP5 shows that the observed BOD data of Yongpo and Daechong Dam in 1999 were 0.8 mg/L and 1.0 mg/L, and simulated data were 0.9 mg/L and 0.9 mg/L, respectively. In case of 1999, average BOD concentrations were 0.8 mg/L and 1.0 mg/L. Simulated concentration showed 1.1 mg/L and 1.5 mg/L, respectively. Generally, the simulation results were in good agreement with the observed data. This study was focused on formulating an integrated model for evaluating ungauged watersheds. Even though simulation results varied slightly due to limited availability of data, the model developed in this study would be a useful tool for the assessment and management of ungauged watersheds.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1679-1683
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• 2008

낙동강 하류지점인 물금은 2003년${\sim}$2005년의 대부분이 부영양화의 기준을 넘고 있다. 하구둑 건설이후, 담수화 된 하구둑 상부에서는 부영양화가 가속화되었다. 수질의 악화는 물론 강 생태계의 구조와 기능의 변화까지 초래되었다. 지난 $7{\sim}8$년 간 낙동강 하류 지역은 갈수기 식물성 플랑크톤 군집의 대거 번성으로 인한 부영양화로 연중 심각한 수질 오염문제를 야기하고 있다. 본 연구는 WASP 7.2 모형과 예측된 동물성플랑크톤을 이용하여 낙동강 유역의 하류 지역인 물금의 부영양화를 예측하는 것이다. 2005년의 관측값을 초기조건으로 고정하고 DO, $NO_3$-N, $PO_4$-P, 기상청에서 예보되는 기온을 사용하여 동물성 플랑크톤을 신경망 모형으로 예측한 뒤, 수온 대신 기상청의 기온을 입력하여 $1{\sim}3$일 후의 단기 수질을 예측하였다. 부영양화 예측결과와 2005년의 월별 수질 관측값을 통계량을 이용하여 분석하였다. $1{\sim}3$일 후의 예측결과 수질항목 중 부영양화의 기준이 되는 클로로필-a, 총 질소, 총 인의 경우는 예측기간 모두 관측값에 적합하게 모의되었다. WASP 7.2 모형의 수질항목 관측자료를 초기값으로 입력하고, 예측된 동물성 플랑크톤의 개체수와 기상청에서 예보되는 기온을 사용한 수질모의는 낙동강의 단기 수질예측에 유의한 의미가 있을 것으로 사료된다.

• Korean journal of applied entomology
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• v.2
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• pp.47-54
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• 1963

The chestnut gall wasp, Dryocosmus kuriphilus $Y^{ASUMATSU}$, has been recently distributed and chestnut trees have teen seriously damaged by this insects in Korea. However, this insect pest has not been investigated in Korea. This paper gives an account of field and Laboratory observations on the seasonal occurrence and the life history of the chestnut gall wasp, and the damage of the chestnut trees by. its insects. This study was carried out at Chungchungpukdo, Kangwon-do and Kyungi-do in Korea, from 1961 to 1963, inclusive. 1. The Chestnut gall wasp (Dryocosmus kuriphilus $Y^{ASUMATSU}$) has one generathion per year and females are only known. 2. The adult wasps were observed from late June to late July with peak of wasp emergence about early and middle July. Most of new adult wasps were coming out from, the galls in the morning rather than the afternoon. 3. Each wasp produced auerage 198.5 eggs and about 4.89 eggs was observed in each bud of the chestnut tree. 4, The egg period of wasps was about 30 days and they were hatching from July to August. 5. The larval period of wasps were from middle of August to middle of next June and pupation took places about early June to middle of July. 6. The adult wasps were ovipositing into the buds and from early May next year, galls were growing. They caused stunting of growth and no fruiting or dying of the chestnut tries. 7. The first observation of the wasp was made at Chaechun of Chungchung-pukdo in 1958. Up to 1963 this insects are distributed in Kangwon-do, Kyunggi-do, north part of Chungchung-pukdo and north part of Kyungsangpukdo

• Journal of Korea Water Resources Association
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• v.56 no.5
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• pp.337-345
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• 2023

Monitoring river microplastics is a challenging task since it is a time-consuming and high-cost process. The use of a physical model to have a better understanding of river microplastics' behaviors can complement the challenging monitoring process. However, there have been very limited studies on modeling river microplastics. In this study, therefore, we evaluated the applicability of one commonly used river water quality model, i.e., the Water Quality Analysis Simulation Program (WASP), in simulating the microplastic concentration in the river environment. We simulated the microplastic concentration in the Anyangcheon stream using the WASP's biochemical oxygen demand (BOD) and suspended solid (SS) variables as possible surrogate variables for the microplastics. Simulation analyses indicate that the SS state variable performs better than the BOD state variable to mimic the observed concentrations of microplastics. This is because of the characteristics of each water quality parameter; the BOD variable, a biochemical indicator, is inappropriate for modeling the behaviors of microplastics, which have generally constant biochemical features. In contrast, the SS variable, which has similar physical behaviors, followed the observed patterns of the microplastic concentrations well. To build a more advanced and accurate model for simulating the microplastic concentration, comprehensive and long-term monitoring studies of the river microplastics under different environmental conditions are needed, and the unit of microplastic concentration should be carefully addressed before its modeling application.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.4
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• pp.146-153
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• 2023

This study aimed to conduct a comprehensive survey of social wasp diversity and its impacts on remote Ulleungdo Island, South Korea. A total of 12 wasp traps were placed across the island, and specimens were collected monthly from May to October. Additional collection was conducted by thoroughly inspecting the areas surrounding the traps. The traps yielded a total of 5,068 individuals, representing two genera and two species. A total of 3,961 Vespa simillima simillima Smith individuals (78.2%) were collected, and 1,107 individuals (21.8%) were identified as Vespula flaviceps flaviceps Smith. Additionally, five individuals of Polistes snelleni de Saussure were collected through sweeping, bringing the total to 5,132 individuals of three genera and three species. It is worth noting that our findings indicate potential misidentifications in the species list of Vespidae found in the literature. Emergency services call centers reported the removal of 60 social wasp nests on Ulleungdo Island between 2018 and 2022, with the highest number of reports occurring from July to September, accounting for 87% of all cases. Dodong-ri and Jeodong-ri, with the highest populations, reported the most incidents, although fortunately, there have been no recent injuries. Past incidents involving the destruction of dried squid products by Vespula species have resulted in significant economic losses, underscoring the need for preventative measures. Furthermore, ongoing surveillance of hornet invasions is essential to safeguard the Jangwon bees being reared on Ulleungdo Island.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.29-36
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• 2007

This study was carried out to develop a water quality simulation model for the evaluation of an ungauged watershed. For this purpose, the WASP5 model was selected and modified. The model consists of three sub-models, LOAD-M, DYN-M, and EUT-M. LOAD-M, an empirical model, estimates runoff loadings using point and non-point source data of villages. The Geum River Estuary watershed was selected to calibrate and verify the Modified-WASP5. The LOAD-M model was established using field data of water quality and quantity at the gauging stations of the watershed and was applied to the ungauged watersheds, taking the watershed properties into consideration. The result of water quality simulation using Modified-WASP5 shows that the observed average BOD data from Gongju and Ganggyeong were 2.6 mg/L and 2.8 mg/L, and the simulated data were 2.5 mg/L and 2.4 mg/L, respectively. Generally, simulation results were in good agreement with the observed data. This study focused on formulating an integrated model for evaluating ungauged watersheds. Even though simulation results varied slightly due to limited availability of data, the model developed in this study would be a useful tool for the assessment and management of ungauged watersheds.

• Journal of Environmental Impact Assessment
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• v.8 no.1
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• pp.93-105
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• 1999

Lately water quality of Daechong Reservoir has become more eutrophicated than ever before and there has been much concern over especially the eutrophication of the embayment near Daejon and Chongju Water Intake Tower every summer. The purpose of this study is to predict the impact of change in the pollutant loading, flowrate, nitrogen and phosphorus release from sediment, SOD(sediment oxygen demand) upon the water quality of Daechong Reservoir by WASP5/EUTR05 in order to suggest water quality management alternatives. The data of Sep. 1995 were used for the calibration of the model and those of Sep. 1997 was for verification. The result of the modeling can be summarized as follows. 1. The 50% increase(decrease) of pollutant loading has caused that of T-N concentration by 0.10-0.14 mg/l, T-P concentration by 0.003-0.005 mg/l, and CBOD concentration by 0.16-0.18 mg/l. But the ratio of DO change by the change of pollutant loading was relatively small. 2. The sensitivity test of NH4 flux to T-N and that of P04 flux to T-P shows that T-N and T-P concentration were changed more in the epilimnion segments (SEG4, SEG5, SEG6, SEG7) than the other segments. As SOD increases, DO was predicted to decrease more especially in the hypolimnion (SEG9-SEG14). 3. As flowrate increase, the concentration of T-N, T-P, and CBOD were predicted to decrease, but DO concentration increased especially in the hypolimnion segments(SEG11, SEG12, SEG13, and SEG14). As the flowrate changed from $119m^3/sec$ to $50m^3/sec$, the concentration of T-N and CBOD in the hypolimnion was predicted to decrease.