• Parasites, Hosts and Diseases
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• 제56권4호
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• pp.341-349
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• 2018

The infection status of Centrocestus armatus metacercariae (CaMc) was broadly surveyed in freshwater fishes from major river systems in the Republic of Korea (Korea) during 2008-2017. A total of 14,977 fishes was caught and examined by the artificial digestion method. CaMc were detected in 3,818 (97.1%) (2,114 Z. platypus: 96.1% and 1,704 Z. temminckii: 98.4%) out of 3,932 Zacco spp. examined and their density was 1,867 (2,109 in Z. platypus and 1,567 in Z. temminckii) per fish infected. The prevalences with CaMc were high, 93.7-100%, in Zacco spp. from all surveyed areas. However, their densities were more or less different by the surveyed areas and fish species. They were most high in Nakdong-gang in Gyeongsangnam-do (4,201 in average), and followed by Geum-gang (2,343), Nakdong-gang in Gyeongsangbuk-do (1,623), Han-gang (1,564), Tamjin-gang and Yeongsan-gang (1,540), streams in the east coast (1,028), Seomjin-gang (488) and Mangyeong-gang (170). In another species of rasborinid fish, Opsariichthys uncirostris amurensis, CaMc were detected in 222 (74.8%) out of 297 ones examined and their density was 278 (1-4,480) per fish infected. CaMc were also detected in total 41 fish species except for the rasborinid fish, Z. platypus, Z. temminckii and O. uncirostris amurensis. Conclusively, it was confirmed that among the 3 species of rasborinid fish, Z. platypus and Z. temminckii are highly prevalent and O. uncirostris amurensis is moderately prevalent with CaMc. Additionally, we could know that variety of fish species act as the second intermediate hosts of C. armatus in Korea.

• 한국물환경학회지
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• 제30권5호
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• pp.539-548
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• 2014

This study was carried out to investigate algal community structures and their correlations with environmental factors on five weir areas in the Nakdong River, South Korea. Water qualities, hydrodynamics, meteorological conditions and algal species compositions were observed in studied sites from May 2010 to Dec. 2013. Results showed that average total phosphorus concentration of 2013 was decreased by 52.4% in comparing with that from 2010 to 2011. Chlorophyll.a concentrations were positive significant with water temperature, pH, total phosphorus and total nitrogen, but is not significant with turbidity and suspended solids. Seasonal successions of algae were observed that Stephanodiscus sp. was dominant species with 65.3% of dominant frequency in studied site. Large algal biomass of the low temperature-adapted diatoms were observed during temperature range of $4{\sim}9^{\circ}C$, but large cyanobacterial biomass mainly during high temperature period ranged from $22^{\circ}C$ to $32^{\circ}C$. Microcystis sp. dominated during high water temperature in summer. The yearly correlations of algal biomass with accumulated solar radiations were not significant but seasonal correlations of summer from June to August were significant with correlation coefficient 0.33 (p<0.05). There were not significant correlations between turbidities and algal biomass. Turbidity and suspended solids concentrations were not significant correlation with algal biomass. According to the results, algal communities had strong correlation with water temperature and had partially correlation with solar radiation. For an effective management of algal blooms, water managers should survey with more long-term monitoring of various environmental factors and algal communities.

• 한국지역지리학회지
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• 제14권1호
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• pp.27-39
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• 2008

본 연구는 낙동강과 그 지류인 금호강에 형성된 호소성 습지의 형성과정을 밝히고자 하였다. 이를 위하여 세 시기의 지형도를 비교 분석하고 단면도를 작성하였으며, 퇴적물의 입경분포를 분석하였다. 그 결과 호소성 습지의 형성 과정을 3가지로 유형화하였다. 첫째, 샛강습지와 금강늪은 망류하천을 이루고 있는 구간에서 분류하여 흐르는 유로의 자유로운 이동 과정에서 남아 형성된 잔적호 습지이다. 둘째, 씩실늪과 낫늪은 배후산지에서 흘러나온 지류가 자연제방의 방해로 유로가 차단되어 자연제방과 평행하게 흘러 본류로 유입되는 yazoo형 습지이다. 셋째, 세천늪과 호촌늪, 진촌늪은 본류 하천의 범람으로 자연제방과 배후습지가 형성된 이후에 다음 홍수시 범람하는 본류 하천이 습지로 유입되어 형성된 범람 유입수형 습지이다.

• 한국물환경학회지
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• 제32권3호
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• pp.271-280
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• 2016

The aim of this study was to analyze spatial and temporal patterns of bacterial pollution levels and the relationship between bacterial pollutants and environmental parameters at the main stream and tributaries of Nakdong River. Water quality data including total coliform and fecal coliform were compiled from a total of 50 monitoring sites (30 at the main stream and 20 at the tributaries) along with rainfall and discharge data for three consecutive years from 2012 to 2014. During the study periods, the geometric mean values of total coliforms and fecal coliforms in the main stream were 74 (22~465) CFU/100 mL and 8 (3~42) CFU/100 mL, respectively. The geometric mean values of total coliforms and fecal coliforms in the tributaries were 275 (36~5,145) CFU/100 mL and 6 (1~1,352) CFU/100 mL, respectively. High concentrations of fecal coliforms were observed at Gumi (M 10), Hyeonpung (M 19), Hapcheon (M 23), and Namji (M 25) in the main stream, whereas Gamcheon (T 6), Bakcheon (T 7), Geumho-gang (T 8), and Gyeseongcheon (T 16) were identified as pollution hot spots in the tributaries. Although bacterial pollution levels showed complex behavior across monitoring sites and time, the highest coliform concentrations were routinely observed in the monsoon season between July and September of each year, indicating that the pollution levels were strongly dependent on precipitation in addition to other physiochemical parameters. Statistically significant correlations were found between fecal coliform concentrations and precipitation (r=0.403, p<0.01), followed by SS (r=0.425, p<0.01), nutrient TP (r=0.388, p<0.01), organic matter COD (r=0.322, p<0.01), and PO₄-P (r=0.317, p<0.01) in the main stream in the order of correlation coefficient from high to low.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2019년도 정기학술대회 발표논문집
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• pp.107-107
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• 2019

• 한국습지학회지
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• 제5권2호
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• pp.43-55
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• 2003

Vegetation structure was investigated in the Hyeonchang wetland and its watershed around the Nakdong-gang, Changryeong-county, Gyeongsangnamdo, Korea. from May to August, 2001. The vegetation type of the Hyeonchang wetland was classified into 12 communities based on the actual vegetation map: Phragmites communis community, Zizania latifolia community, Phragmites communis - Persicaria perfoliata community, Salix koreensis community, Persicaria perfoliata - Phragmites communis community, Spirodela polyrhiza community, Persicaria perfoliata community, Cyperus amuricus community, Cyperus amuricus-EchinochJoa crus-galli var. frumentacea community, Phragmites communis-Zizania latifolia community, EchinochJoa crus-galli var. frumentacea community, and Persicaria maackiana community. Among them, Phragmites communis community was the largest (4.3 ha, 24%). The dominant vegetation type were Phragmites communis community, Echinochloa crus-galli var. frumentacea-Persicaria maackiana community, and Cyperus amuricus subcommunity based on the phytosociological method. The vegetation type of the Hyeonchang wetland watershed was classified into five communities based on the actual vegetation map: Pinus densilflora community, Pinus rigida community, Pinus densiflora-Quercus acutissima community, Pinus densiflora-Larix gmelini var. principis-ruprechtii community, and Populus tomentiglandulosa community. Among them, Distribution area of Pinus densiflora community was largest (399.3 ha, 61.8%). And the degree of green naturality of the Pinus densiflora community was 7 and 8 degree.

• 한국자원식물학회지
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• 제32권5호
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• pp.615-632
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• 2019

본 연구는 경상북도 중북부지역 낙동강 중류의 하천 식물상을 밝히고, 생활형을 파악하여 향후 유사지역 하천에서의 관속식물상 조사연구에 기초자료를 제공하고자 실시하였다. 현지조사는 2016년 5월부터 10월, 2017년 4월부터 10월에 걸쳐 영강, 내성천, 병성천, 위천 및 감천 등 5개 하천에서 실시하였고, 조사결과 조사지역에서 생육하는 관속식물은 99과 288속 421종 4아종 39변종 10품종 등 총 474분류군이었다. 이 중 양치식물은 8과 8속 10종 1변종 등 11분류군, 나자식물은 3과 3속 4종 등 4분류군, 쌍자엽식물 73과 217속 312종 3아종 25변종 8품종 등 348분류군, 단자엽식물 14과 60속 95종 1아종 13변종 2품종 등 111분류군으로 나타났다. 특산식물은 5분류군이 조사되었고, 식물구계학적특정종으로 중요도가 높은 III등급 이상을 살펴보면 V등급은 조사되지 않았으며, IV등급 3분류군, III등급 5분류군이 조사되었다. 희귀식물은 7분류군이 조사되었고, 귀화식물은 73분류군으로 조사되었다. 조사지역 소산식물의 생활형 분석결과 Th 159분류군, H 91분류군, HH 68분류군, G 52분류군, N 35분류군, MM 32분류군, M 25분류군, Ch 12분류군, E 1분류군 등으로 나타났다.

• 물과 미래
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• 제12권2호
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• pp.63-69
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• 1979

The sequences of monthly streamflows constitute a non-statonary time series. The purely stochastic model has been applied to data generation of non-stationary time series. Tow different mothods--single site and multisite generation--have been used on the hydrologic time series. In this study the synthetic generation method by bivariate analysis, studied by Thomas Fiering, one of multi-site models, has been applied to the historical data on monthly streamflows at two sites in Nakdong River, and also for validity of this model the single site Thomas Fiering model applied. Through statistical analysis it has been shown that the performance of bivariate Thomas Fiering model was better than that of the other. By comparison of mean and standard deviaion between the historical and the generated, and cross correlogram interpretation, it has been known that the model used herein has good performance to simultaneously generate the monthly streamflows at two sites in a river hasin.

• 한국수자원학회논문집
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• 제41권4호
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• pp.395-404
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• 2008

충적하천의 복잡하고 다양한 이동특성을 파악하고 이해하는 것은 하천공학적으로 매우 중요하며, 본 연구에서는 저수로의 이동 및 하상저하로 인하여 취수문제가 있는 경상북도 구미시에 위치한 해평취수장 주변에 대하여 항공사진 분석을 통하여, 시간에 따른 하천의 지형변화, 저수로의 이동 특성을 조사하고 분석하였다. 저수로는 좌안에서 우안으로 이동해 가고 있으며, 저수로는 강턱유량에 대하여 복렬사주가 발달하는 특성을 보여주고 있다. 이는 하천의 경사가 급하고 하폭이 넓고 수심이 얕은 곳에서 발생하는 현상으로서, 저수로의 불안정성이 증가하기 때문이다. 또한 저수로의 사행도가 감소하면서 저수로 폭이 증가하는 것은 제한된 범위 안에서 저수로의 분류와 합류가 활발하게 발생하는 것을 의미한다. 시간의 증가에 따라 저수로 하폭의 증가율과 측방향 이동율은 감소하고 있다. 강턱유량을 이용하여 중규모 영역구분을 수행한 결과, 복렬사주가 발달하는 하천의 특성을 보여주었으며, 모래하천으로서 부유사가 지배적인 하천으로 판단되었다.

• 한국수자원학회논문집
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• 제31권1호
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• pp.71-84
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• 1998

낙동강 유역의 저수유출 해석을 위해 IS(integrated snowband) 유역모형이 포함된 SSARR 모형을 적용하였다. IS유역모형은 증발산, 침투 및 장기회귀 지하수 추적기능이 추가된 최신 버전으로서 연물수지분석에 관한 정보가 출력되며 대화식 구동방식인 IA(interactive)방식도 내재되어 있다. 고수시와 저수시 민감한 매개변수를 민감도 분석결과 도출할 수 있었고, 이를 토대로 모형의 보정이 이루어졌다. 7개 제어지점에서 유량의 관측치와 계산치를 비교하여 고수시 상대오차와 저수시 절대오차를 통하여 모형의 검증을 수행하였다. IS 유역모형을 사용하여 월별 물수지 분석을 수행하였다.