자연유황 회복을 위한 댐 운영에 따른 금강의 물리서식처 변화 분석 = Investigation of the change in physical habitat in the Geum-gang River by modifying dam operations to natural flow regime

다국어 초록 (Multilingual Abstract)

In general, the upstream dam changes downstream flow regime dramatically, i.e., from natural flow regime to hydropeaking flows. This study investigates the impact of the natural flow pattern on downstream fish habitat in a regulated river in Korea using the physical habitat simulation. The study area is a 13.4 km long reach of the Geum-gang River, located downstream from the Yongdam Dam, Korea. A field monitoring revealed that three fish species are dominant, namely Zacco platypus, Coreoleuciscus splendidus, and Opsariichthys bidens, and they account for 70% of the total fish community. Specially, Opsariichthys bidens is an indigenous species in the Geum-gang River. The three fish species are selected as target fish species for the physical habitat simulation. The Nays2D model, a 2D shallow water equation solver, and the HSI (Habitat Suitability Index) model are used for hydraulic and habitat simulations, respectively. To assess the impact of the natural flow pattern, this study uses the annual natural flow regime and hydropeaking flows from the dam. It is found that the natural flow regime increases significantly the Composite Suitability Index (CSI) in the study reach. Then, using the Building Block Approach (BBA), the scenarios for the modifying dam operations are presented in the study reach. Both Scenario 1 and scenario 2 are proposed by using the hydrological method considering both magnitude and duration of the inflow and averaging the inflow over each month, respectively. It is revealed that the natural flow regime embodied in scenario 1 and scenario 2 increases the Weighted Usable Area (WUA) significantly, compared to the hydropeaking flows. In conclusion, the modifying the dam operations by restoring to the natural flow pattern is advantageous to fish community.

국문 초록 (Abstract)

일반적으로 상류의 댐은 하류 유황을 자연 상태에서 발전방류 조건으로 심각하게 변화시킨다. 본 연구에서는 물리서식처모의를 통하여 국내 조절하천에서 자연유황 패턴이 하류의 어류 서식처에 미치는 영향을 조사하였다. 연구 대상하도는 금강의 용담댐 하류 13.4 km 구간으로 설정하였다. 현장조사 결과, 대상하도에서 피라미, 쉬리, 그리고 끄리가 우점하고 있는 것으로 나타났으며, 이들이 전체의 70%를 차지하고 있는 것으로 파악되었다. 이중 끄리는 금강에 서식하는 토착어종이다. 이들 3종을 물리서식처모의를 위한 대상어종으로 선정하였다. 수리해석과 서식처모의를 위하여 2차원 천수방정식에 기반한 Nays2D 모형과 HIS 모형을 각각 사용하였다. 자연 유황에 따른 영향을 검토하기 위하여, 본 연구에서는 댐 유입 유량과 발전유량을 이용하였다. 물리서식처모의 결과, 자연유황 조건에서 대상하도의 복합서식처지수가 크게 증가하는 것으로 나타났다. 그리고 BBA 방법을 이용하여 대상하도에 자연유황에 대한 댐 운영 시나리오를 제시하였다. 시나리오 1을 위하여 유입유량의 양과 지속기간을 고려하는 수문학적 방법을 이용하였고, 시나리오 2는 유입유량을 월별로 평균하여 구축하였다. 시나리오 1과 시나리오 2를 통해서 구현된 자연유황 조건이 발전방류에 비해 가중가용면적을 크게 증가시키는 것으로 나타났다. 결과적으로 댐 운영을 자연유황 조건으로 변환시켜 방류하였을 때 하류의 어류 서식처를 개선하는데 도움이 되는 것으로 확인되었다.

참고문헌 (Reference)

1 허준욱, "한강의 대표적 하천에 서식하는 참갈겨니 (Zacco koreanus)의 물리적 서식조건에 관한 연구" 한국환경영향평가학회 20 (20): 206-214, 2011

2 허준욱, "금강수계에서 하상재료에 따른 어류의 종다양성 및 서식지 평가" 한국환경영향평가학회 20 (20): 845-856, 2011

3 Shimizu, Y., "iRIC software Nays2D solver manual"

4 Catlin, A. K., "Zooplankton generation following inundation of floodplain soils: Effects of vegetation type and riverine connectivity" 68 (68): 76-86, 2017

5 Zolezzi, G., "Thermopeaking in Alpine streams: Event characterization and time scales" 4 (4): 564-576, 2011

6 Gupta, H., "The role of mega dams in reducing sediment fluxes: A case study of large Asian rivers" 464 : 447-458, 2012

7 Poff, N. L., "The natural flow regime: A paradigm for river conservation and restoration" 47 : 769-784, 1997

8 Benjankar, R., "The impact of river modification and dam operation on floodplain vegetation succession trends in the Kootenai River" 46 : 88-97, 2012

9 Todd, C. R., "The impact of cold water releases on the critical period of post‐spawning survival and its implications for Murray cod (Maccullochella peelii peelii): A case study of the Mitta Mitta River, southeastern Australia" 21 (21): 1035-1052, 2005

10 강형식, "The Effects of Cold Water Released from Dams on Zacco platypus Gonad Maturation in the Nakdong River, South Korea" 대한토목학회 21 (21): 1473-1483, 2017

11 Clarkson, R. W., "Temperature effects of hypolimnial-release dams on early life stages of Colorado River basin big-river fishes" 2000 (2000): 402-412, 2000

12 Yeom, D. H., "Stressor identification and health assessment of fish exposed to wastewater effluents in Miho Stream, South Korea" 67 : 2282-2292, 2007

13 U. S. Fish and Wildlife Service(USFWS), "Standards for the development of habitat suitability index models. 103 ESM"

14 McCully, P., "Silenced rivers: The ecology and politics of large dams" Zed Books 1996

15 Gibbins, C. N., "Salmonid habitat modelling studies and their contribution to the development of an ecologically acceptable release policy for Kielder Reservoir, North‐east England" 16 (16): 203-224, 2000

16 Postel, S., "Rivers for life: Managing water for people and nature" Island Press 2003

17 Tockner, K., "Riverine flood plains:Present state and future trends" 29 (29): 308-330, 2002

18 Richter, B., "Restoring environmental flows by modifying dam operations" 12 (12): 12-, 2007

19 Baldwin, D. S., "Restoring dissolved organic carbon subsidies from floodplains to lowland river food webs: A role for environmental flows?" 67 (67): 1387-1399, 2016

20 Willis, C. M., "Reductions in fluvial sediment discharge by coastal dams in California and implications for beach sustainability" 111 (111): 167-182, 2003

21 Choi, B., "Physical habitat simulations of the Dal River in Korea using GEP model" 83 : 456-465, 2015

22 Kondolf, G. M, "PROFILE: Hungry water: Effects of dams and gravel mining on river channels" 21 (21): 533-551, 1997

23 Li, R., "Modelling the impacts of reservoir operations on the downstream riparian vegetation and fish habitats in the Lijiang River" 13 (13): 229-244, 2011

24 Valentin, S., "Modelling temporal variations of physical habitat for brown trout (Salmo trutta) in hydropeaking conditions" 12 (12): 317-330, 1996

25 Milhous, R. T, "Mixing physical habitat and streamflow time series analysis" 14 : 69-91, 2004

26 Gosse, J.C, "Microhabitat of rainbow and cutthroat trout in the green river below flaming Gorge Dam" Utah Division of Wildlife Resources, Ministry of Science and Technology 114-, 1982

27 Ministry of Land, Infrastructure and Transport (MOLIT), "Integrated river restoration manual"

28 Choi, S. U., "Impact of hydropeaking on downstream fish habitat at the Goesan Dam in Korea" 10 (10): e1861-, 2017

29 Choi, B., "Impact of hydropeaking and thermopeaking on the downstream habitat in the Dal River, Korea" 43 : 1-11, 2018

30 International River Interface Corparative (iRIC), "Guide book on iRIC Seminar in KANSAI, iRIC Project" Silicon Graphics, Inc 2013

31 Rosenberg, D. M., "Globalscale environmental effects of hydrological alterations: Introduction" 50 (50): 746-751, 2000

32 Ahern, M., "Global health impacts of floods: Epidemiologic evidence" 27 (27): 36-46, 2005

33 Mueller, E. R., "Geomorphic change and sediment transport during a small artificial flood in a transformed post-dam delta: The Colorado River delta, United States and Mexico" 106 : 757-775, 2016

34 Nilsson, C., "Fragmentation and flow regulation of the world’s large river systems" 308 (308): 405-408, 2005

35 Shafroth, P. B., "Establishment of woody riparian vegetation in relation to annual patterns of streamflow, Bill Williams River, Arizona" 18 : 577-590, 1998

36 King, J. M., "Environmental flow assessments for rivers: Manual for the building block methodology" Water Research Commission 2008

37 Lessard, J. L., "Effects of elevated water temperature on fish and macroinvertebrate communities below small dams" 19 (19): 721-732, 2003

38 Zadereev, E. S., "Ecology of Meromictic Lakes Vol. 228" Springer 61-86, 2017

39 Richter, B. D., "Ecologically sustainable water management: Managing river flows for river integrity" 13 : 206-224, 2003

40 Garcia, A., "Downstream environmental effects of dam operations: Changes in habitat quality for native fish species" 27 (27): 212-327, 2011

41 Williams, G. P., "Downstream effects of dams on alluvial rivers" U.S. Geological Survey, U.S. Department of the Interior 1984

42 Ministry of Land, Transport and Maritime Affairs (MLTMA), "Development of techniques for creation of wildlife habitat environment" 2011

43 Collier, M., "Dams and rivers: Primer on the downstream effects of dams" US Geological Survey, US Department of the Interior 1996

44 World Commission on Dams(WCD), "Dams and development:A new framework for decision-making" Earthscan Publication Ltd 2000

45 Reusser, L. J., "Characterizing landscape‐scale erosion using 10Be in detrital fluvial sediment: Slope‐based sampling strategy detects the effect of widespread dams" 53 (53): 4476-4486, 2017

46 Bunn, S. E., "Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity" 30 : 492-507, 2002

47 Boavida, I., "Barbel habitat alterations due to hydropeaking" 9 : 237-247, 2015

48 King, J. M., "Assessment of the instream flow incremental methodology and initial development of alternative instream flow methodologies for South Africa" Water Research Commission 1994

49 Booker, D. J., "Application of physical habitat simulation (PHABSIM) modelling to modified urban river channels" 20 (20): 167-183, 2004

50 Vörösmarty, C. J., "Anthropogenic sediment retention:Major global impact from registered river impoundments" 39 (39): 169-190, 2003

51 Richter, B. D., "A collaborative and adaptive process for developing environmental flow recommendations" 22 : 297-318, 2006