Short Note

Split Viewer

Econ. Environ. Geol. 2022; 55(1): 45-51

Published online February 28, 2022

https://doi.org/10.9719/EEG.2022.55.1.45

© THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY

Hydrological Characteristics of the Underground Discharge at Moolgol in Dokdo, Korea

Nam C. Woo1,*, Dong Y. Lee1, Jong H. Park1, Yoon B. Kim2, Min S. Woo2, Chan H. Park3

1Department of Earth System Sciences, Yonsei University, Seoul, Korea 03722
2Ulleungdo·Dokdo Ocean Research Station, Korea Institute of Ocean Science and Technology (KIOST), Uljin, Korea 36315
3Dokdo Research Center, Korea Institute of Ocean Science and Technology (KIOST), Uljin, Korea 36315

Correspondence to : *Corresponding author : ncwoo@yonsei.ac.kr

Received: February 21, 2022; Revised: February 24, 2022; Accepted: February 24, 2022

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided original work is properly cited.

Abstract

Whether Dokdo can sustain human habitation or economic life of their own plays an important role to the legal status of the island in the international maritime law. This study reports the hydrological survey results regarding the water resource of the island occurred at Moolgol in Seodo. The amount of underground discharge at Moolgol was estimated at least 1.1 m3/d, conforming the results of previous studies. Based on the oxygen and hydrogen isotope ratios of water, the discharge appeared to originate from precipitation, and about 36% of the daily precipitation moves fast to the Moolgol through the joints developed in the volcanic bedrocks. Quality of the discharged water shows relatively higher concentrations in Cl and NO3 to be used for drinking and domestic purposes, probably affected by the sea spray and waves from surrounding sea and the birds’ excretion such as black-tailed gulls.

Keywords Moolgol, Dokdo, underground discharge, water stable isotope, discharge rate, water quality

독도 물골 지하유출수의 수문학적 특성

우남칠1,* · 이동엽1 · 박종훈1 · 김윤배2 · 우민수2 · 박찬홍3

1연세대학교 지구시스템과학과
2한국해양과학기술원 동해연구소
3한국해양과학기술원 독도전문연구센터

요 약

독도에서의 “인간의 거주 혹은 독자적인 경제활동을 영위할 수 있는가의 여부”는 국제법 상으로 독도의 지위를 결정하는 중요한 요소로 작용한다. 이러한 관점에서 독도의 활용가능한 물(water resource)에 대하여, 독도에서 유일하게 지하수 유출이 발생하고 있는 서도의 물골을 대상으로 조사한 수문학적 결과를 보고한다. 이 조사에서 평가한 물골의 지하수 유출량은 최소 1.1 m3/d로 나타났으며, 이는 기존의 연구들에서 제시한 결과와 통계적으로 유사하다. 물의 산소-수소 안정동위원소비를 통한 기원 분석에서 지하유출수의 기원은 강수로 판단되며, 일강수량을 기준으로 할 때, 강수의 약 36% 정도는 화산암 내의 절리를 통해 빠르게 지하수로 유출된다. 지하유출수의 수질은 생활용수와 음용수로 사용하기에는 높은 염도와 질산염 농도를 보이며, 이들은 해무와 파도 등에 의한 염분과 괭이 갈매기 등 조류 배설물로부터 기인된 것으로 판단된다.

주요어 물골, 독도, 지하유출수, 물 안정동위원소, 유출량, 수질

Article

Short Note

Econ. Environ. Geol. 2022; 55(1): 45-51

Published online February 28, 2022 https://doi.org/10.9719/EEG.2022.55.1.45

Copyright © THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY.

Hydrological Characteristics of the Underground Discharge at Moolgol in Dokdo, Korea

Nam C. Woo1,*, Dong Y. Lee1, Jong H. Park1, Yoon B. Kim2, Min S. Woo2, Chan H. Park3

1Department of Earth System Sciences, Yonsei University, Seoul, Korea 03722
2Ulleungdo·Dokdo Ocean Research Station, Korea Institute of Ocean Science and Technology (KIOST), Uljin, Korea 36315
3Dokdo Research Center, Korea Institute of Ocean Science and Technology (KIOST), Uljin, Korea 36315

Correspondence to:*Corresponding author : ncwoo@yonsei.ac.kr

Received: February 21, 2022; Revised: February 24, 2022; Accepted: February 24, 2022

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided original work is properly cited.

Abstract

Whether Dokdo can sustain human habitation or economic life of their own plays an important role to the legal status of the island in the international maritime law. This study reports the hydrological survey results regarding the water resource of the island occurred at Moolgol in Seodo. The amount of underground discharge at Moolgol was estimated at least 1.1 m3/d, conforming the results of previous studies. Based on the oxygen and hydrogen isotope ratios of water, the discharge appeared to originate from precipitation, and about 36% of the daily precipitation moves fast to the Moolgol through the joints developed in the volcanic bedrocks. Quality of the discharged water shows relatively higher concentrations in Cl and NO3 to be used for drinking and domestic purposes, probably affected by the sea spray and waves from surrounding sea and the birds’ excretion such as black-tailed gulls.

Keywords Moolgol, Dokdo, underground discharge, water stable isotope, discharge rate, water quality

독도 물골 지하유출수의 수문학적 특성

우남칠1,* · 이동엽1 · 박종훈1 · 김윤배2 · 우민수2 · 박찬홍3

1연세대학교 지구시스템과학과
2한국해양과학기술원 동해연구소
3한국해양과학기술원 독도전문연구센터

Received: February 21, 2022; Revised: February 24, 2022; Accepted: February 24, 2022

요 약

독도에서의 “인간의 거주 혹은 독자적인 경제활동을 영위할 수 있는가의 여부”는 국제법 상으로 독도의 지위를 결정하는 중요한 요소로 작용한다. 이러한 관점에서 독도의 활용가능한 물(water resource)에 대하여, 독도에서 유일하게 지하수 유출이 발생하고 있는 서도의 물골을 대상으로 조사한 수문학적 결과를 보고한다. 이 조사에서 평가한 물골의 지하수 유출량은 최소 1.1 m3/d로 나타났으며, 이는 기존의 연구들에서 제시한 결과와 통계적으로 유사하다. 물의 산소-수소 안정동위원소비를 통한 기원 분석에서 지하유출수의 기원은 강수로 판단되며, 일강수량을 기준으로 할 때, 강수의 약 36% 정도는 화산암 내의 절리를 통해 빠르게 지하수로 유출된다. 지하유출수의 수질은 생활용수와 음용수로 사용하기에는 높은 염도와 질산염 농도를 보이며, 이들은 해무와 파도 등에 의한 염분과 괭이 갈매기 등 조류 배설물로부터 기인된 것으로 판단된다.

주요어 물골, 독도, 지하유출수, 물 안정동위원소, 유출량, 수질

    Fig 1.

    Figure 1.Location and the areal view of Seodo and the Moolgol in July, 2021.
    Economic and Environmental Geology 2022; 55: 45-51https://doi.org/10.9719/EEG.2022.55.1.45

    Fig 2.

    Figure 2.Planar view of the water collecting system and the internal view of the Moolgol in July, 2021.
    Economic and Environmental Geology 2022; 55: 45-51https://doi.org/10.9719/EEG.2022.55.1.45

    Fig 3.

    Figure 3.Geologic Map of the Seodo and the location of Moolgol (Kee et al., 2012).
    Economic and Environmental Geology 2022; 55: 45-51https://doi.org/10.9719/EEG.2022.55.1.45

    Fig 4.

    Figure 4.Vertical section of the Moolgol water-collecting system and the water level on May 14th, 2021.
    Economic and Environmental Geology 2022; 55: 45-51https://doi.org/10.9719/EEG.2022.55.1.45

    Fig 5.

    Figure 5.Oxygen and hydrogen stable isotope ratios of the rainfalls from Dokdo and the water samples from the the Moolgol reservoir: D-1, D-2, D-3 samples were collected at depths below ground surface of –70, -50, -30 cm, respectively, from the Moolgol reservoir that shown a layered water column.
    Economic and Environmental Geology 2022; 55: 45-51https://doi.org/10.9719/EEG.2022.55.1.45

    Fig 6.

    Figure 6.Blocked water flow from the collecting reservoir to the storage tank and to drain outlet at the Moolgol on May 14th, 2021.
    Economic and Environmental Geology 2022; 55: 45-51https://doi.org/10.9719/EEG.2022.55.1.45

    Table 1 . Discharge rate measurements at the water reservoir of Moolgol.

    Exp. dateDischarge rate (m3/d)Previous rainfall (mm) with dateRemarks
    2008.04.261.411.5 (2008.04.22)Cho et al., 2011
    2009.06.171.12-Cho et al., 2012
    2009.10.057.0216.0 (2009.10.02~03)Cho et al., 2013
    2010.08.213.023.5 (2010.08.17)Cho et al., 2014
    2010.10.244.034.5 (2010.10.18)Cho et al., 2015
    2021.07.132.728.0 (2021.07.09)This study
    2021.08.201.433.0 (2021.08.17)This study

    Table 2 . Oxygen and hydrogen stable isotope ratios of precipitations at Dokdo and Moolgol underground discharge with Cl concentrations.

    Sample #Dateδ18Oδ2HCl
    mg/L
    Precipitation2021.05.16-3.72-22.6
    2021.05.18-5.76-40.8
    2021.05.20-3.65-26.9
    2021.05.28-6.40-44.437.84
    2021.06.03-5.49-36.2
    2021.06.12-3.90-20.9250.77
    2021.07.04-6.01-39.7231.29
    2021.07.06-7.32-48.7
    D-1* (-70 cm)2021.05.14-5.1-29.47,718
    D-2 (-50 cm)2021.05.14-6.5-39.15,923
    D-3 (-30 cm)2021.05.14-7.0-43.7789
    Seawater 12021.05.14-0.101.218,734
    Seawater 22021.05.140.001.118,550
    Moolgol**2021.07.14-7.25-43.2670

    * D-1, D-2, D-3 samples were collected at depths below ground surface of –70, -50, -30 cm, respectively, from the Moolgol reservoir that shown a layered water column..

    ** Moolgol sample indicates that the one was collected from the newly recharged reservoir..


    Table 3 . Water-quality parameters of the samples from the Moolgol water reservoir and sea water of the shoreline of Seodo.

    SampleTemppHECClBrNO3SO4Remarks*
    °CmS/cmmg/L
    D-115.97.94157,71826.01531,418-70 cm bgs
    D-216.07.85115,92310.2179547-50 cm bgs
    D-316.37.343.47892.6168140-30 cm bgs
    Moolgol670189184newly recharged
    Sea-15318,73464<100**2,549
    Sea-25318,55064<1002,533

    * Remarks indicate the sampling depths below ground surface. At the sampling time, the water level was –20 cm bgs..

    ** NO3 concentrations were shown with the detection limit reflecting the dilution rates..


    KSEEG
    Apr 30, 2024 Vol.57 No.2, pp. 107~280

    Stats or Metrics

    Share this article on

    • kakao talk
    • line

    Related articles in KSEEG

    Economic and Environmental Geology

    pISSN 1225-7281
    eISSN 2288-7962
    qr-code Download