All Issue

2026 Vol.32, Issue 3 Preview Page
Sediment Source Tracing Using Fallout Radionuclides and Connectivity Assessment in the Saguling Dam Reservoir Catchment, Indonesia

방사성동위원소를 이용한 사굴링댐 저수지 퇴적물의 기원지 추정 및 토사 연결성의 정량적 분석

임영신1 · 기신우2 · 김예원3 · Luki Subehi4 · 김진관5

Lim, Young Shin1 · Ki, Shinwoo2 · Kim, Yeawon3 · Luki Subehi4 · Kim, Jin Kwan5

1제1저자, 육군사관학교 토목환경학과 조교수
2공동저자, 전남대학교 지리교육과 박사과정
3공동저자, 전남대학교 지질환경과학부 박사과정
4공동저자, 인도네시아 국가과학기술연구혁신청 호소수자원 연구센터 선임연구원
5교신저자, 전남대학교 지리교육과/지질환경과학과/지질환경재해연구소 교수
1First Author, Assistant Professor, Department of Civil and Environmental Engineering, Korea Military Academy
2Co-Author, Doctoral student, Department of Geological and Environmental Sciences, Chonnam National
3Co-Author, Doctoral student, Department of Geological and Environmental Sciences, Chonnam National
4Co-Author, Senior Researcher, Research Center for Limnology and Water Resources, National Research and Innovation Agency (BRIN), Indonesia
5Corresponding Author, Professor, Department of Geography Education/Department of Geological and Environmental Sciences/Institute of Geological and Environmental Disaster Research, Chonnam National University
31 August 2026. pp. 189-214
PDF Citation
Abstract
This study monitored reservoir sediment accumulation at two locations in the Saguling Dam reservoir, Indonesia, from December 2021 to July 2022—a period characterized by La Niña–induced wet-dry conditions—and traced sediment sources using fallout radionuclides excess 210Pb(210Pbex). At the site near the tributary inflow, immediate sedimentation patterns were observed, reaching a peak deposition rate(6.856 kg/m2) during concentrated rainfall events. Conversely, the internal reservoir site exhibited low sedimentation rates throughout the monitoring period; fine suspended materials passed through the stagnant water body, resulting in continuous influx and deposition. Based on the statistically significant differences in 210Pbex activities between forest topsoil and riverbank materials, sediment source fingerprinting revealed a higher contribution from riverbanks during the wet season. These results suggest that while overall low catchment connectivity limited the transport of slope topsoil to the stream, runoff concentrated along highly connected slopes triggered riverbank erosion and failure, delivering substantial amounts of bank material directly into the channel network system. Under prolonged wet season conditions, rapid sedimentation at the reservoir inlet occurs simultaneously with the continuous accumulation of fine-grained sediment within stagnant reservoir zones, accelerating the loss of storage capacity in the Saguling Dam. Therefore, to fundamentally mitigate reservoir siltation, tailored sediment management strategies must prioritize highly connected slopes and erosion-prone riverbank reaches alongside general topsoil conservation. The findings of this study provide foundational data for controlling sediment influx and establishing efficient, sustainable reservoir management strategies.
Keywords
sediment source tracing
fingerprinting
sediment connectivity
Saguling dam
Citarum river
본 연구는 인도네시아 사굴링 댐 저수지 유역을 대상으로 라니냐에 따른 wet dry season이 나타났던 2021년 12월부터 2022년 7월까지 저수지 두 지점에서 퇴적물을 모니터링하고, 방사성동위원소를 추적자로 이용하여 퇴적물의 기원지를 추정하였다. 지류 유입부 인근 지점은 집중강우가 발생한 시기에 최대 퇴적률(6.856kg/m2)을 기록하며 즉각적인 퇴적 양상이 관측되었다. 반면, 저수지 내부 지점은 모니터링 전기간 동안 낮은 퇴적률이 나타났으며, 세립질 부유물질이 뜬짐 형태로 긴 정체 수역을 통과하여 샘플링 지점에 지속적으로 유입 및 퇴적되었다. 산사면 표토와 하안 물질의 210Pbex 값이 통계적으로 유의미한 차이를 보여 이를 추적자로 이용한 기원지 분석을 수행한 결과, 우기 동안 하안 물질이 상대적으로 더 높은 기여율을 나타냈다. 이러한 결과는 유역 전반의 낮은 연결성으로 인해 사면 표토의 하천 도달률은 낮은 반면, 고연결성 사면으로 집중된 유출수가 하안 침식 및 붕괴를 유발하여 다량의 하안 물질을 하천에 직접 공급했음을 시사한다. 특히 우기가 장기화되는 조건에서는 저수지 유입부의 급격한 퇴적과 저수지 내부 정체 수역 내 세립질 토사의 지속적 누적이 동시에 진행되어 사굴링 댐의 저수용량을 빠르게 감소시킬 수 있다. 따라서 사굴링 댐 저수지의 퇴사 문제를 근본적으로 해결하기 위해서는 유역 전반의 표토 침식 제어뿐만 아니라, 고연결성 사면 및 하안 침식 취약 구간을 최우선 관리 구역으로 선정하여 맞춤형 토사 관리 대책을 적용할 필요가 있다. 본 연구 결과는 저수지 내 유입 토사를 제어하고 효율적인 저수지 관리 전략을 수립하는데 기초자료로 활용될 수 있다.
키워드
퇴적물 기원지 추정
지문기법
토사 연결성
사굴링 댐
시타룸 강
References
  1. 김진관·이찬주·김예원·기신우, 2026, 영산강 담양습지의 형성시기와 퇴적환경 변화, 지역과 지리, 32(1), 214-236. 10.26863/JKARG.2026.2.32.1.214
  2. 김진관·임영신·기신우·김예원, 2022, 만경강 신천습지의 형성시기와 퇴적환경 변화, 지역과 지리, 28(1), 24-35. 10.26863/JKARG.2022.2.28.1.24
  3. 임영신·Luki Subehi·김진관, 2023, 인도네시아 Citarum 강 사굴링 댐 유역의 토양 침식 및 토사 연결성에 대한 고찰, 한국지형학회지, 30(1), 25-41. 10.16968/JKGA.30.1.25
  4. 임영신·기신우·김예원·Luki Subehi·김진관, 2024, RUSLE를 이용한 사굴링 댐 저수지 유역의 토양 유실량 및 침식 위험 평가, 한국지형학회지, 31(4), 29-45. 10.16968/JKGA.31.4.29
  5. Abidin, H.Z., Gumilar, I., Andreas, H., Murdohardono, D., and Fukuda, Y., 2013, On causes and impacts of land subsidence in Bandung Basin, Indonesia, Environmental Earth Sciences, 68(6), 1545-1553. 10.1007/s12665-012-1848-z
  6. Borselli, L., Cassi, P., and Torri, D., 2008, Prolegomena to sediment and flow connectivity in the landscape: A GIS and field numerical assessment, Catena, 75(3), 268-277. 10.1016/j.catena.2008.07.006
  7. Bracken, L.J., Turnbull, L., Wainwright, J., and Bogaart, P., 2015, Sediment connectivity: a framework for understanding sediment transfer at multiple scales, Earth Surface Processes and Landforms, 40(2), 177-188. 10.1002/esp.3635
  8. Cavalli, M., Trevisani, S., Comiti, F., and Marchi, L., 2013, Geomorphometric assessment of spatial sediment connectivity in small Alpine catchments, Geomorphology, 188, 31-41. 10.1016/j.geomorph.2012.05.007
  9. Chaidar, A.N., Soekarno, I., Wiyono, A., and Nugroho, J., 2017, Spatial analysis of erosion and land criticality of the upstream citarum watershed, International Journal of GEOMATE, 13(37), 133-140. 10.21660/2017.37.34572
  10. Collins, A.L., Walling, D., and Leeks, G., 1997, Source type ascription for fluvial suspended sediment based on a quantitative composite fingerprinting technique, Catena, 29(1), 1-27. 10.1016/S0341-8162(96)00064-1
  11. Collins, A.L., Zhang, Y., Walling, D.E., Grenfell, S.E., Smith, P., Grischeff, J., Locke, A., Sweetapple, A., and Brogden, D., 2011, Quantifying fine-grained sediment sources in the River Axe catchment, southwest England: application of a Monte Carlo numerical modelling framework incorporating local and genetic algorithm optimisation, Hydrological Processes, 26, 1962-1983. 10.1002/hyp.8283
  12. Collins, A.L., Pulley, S., Foster, I.D., Gellis, A., Porto, P., and Horowitz, A.J., 2017, Sediment source fingerprinting as an aid to catchment management: a review of the current state of knowledge and a methodological decision-tree for end-users, Journal of Environmental Management, 194, 86-108. 10.1016/j.jenvman.2016.09.075
  13. Cooper, R.J., Krueger, T., Hiscock, K.M., and Rawlins, B.G., 2015, High-temporal resolution fluvial sediment source fingerprinting with uncertainty: A Bayesian approach, Earth Surface Processes and Landforms, 40(1), 78-92. 10.1002/esp.3621
  14. Cox, T., Laceby, J.P., Roth, T., and Alewell, C., 2023, Less is more? A novel method for identifying and evaluating non-informative tracers in sediment source mixing models, Journal of Soils and Sediments, 23(8), 3241-3261. 10.1007/s11368-023-03573-0
  15. Dam, M.A.C., Suparan, P., Nossin, J.J., Voskuil, R.P.G.A., and GTL Group, 1996, A chronology for geomorphological developments in the greater Bandung area, West-Java, Indonesia, Journal of Southeast Asian Earth Sciences, 14, 101-115. 10.1016/S0743-9547(96)00069-4
  16. Djuwansah, M.R., Mulyono, A., and Harryanto, R., 2019, Current ability of 137Cs radionuclear fallout method for erosion assessment in Indonesia, in IOP Conference Series: Earth and Environmental Science, 393(1), 012062. 10.1088/1755-1315/393/1/012062
  17. Evrard, O., Laceby, J.P., Huon, S., Lefèvre, I., Sengtaheuanghoung, O., and Ribolzi, O., 2016, Combining multiple fallout radionuclides (137Cs, 7Be, 210Pbxs) to investigate temporal sediment source dynamics in tropical, ephemeral riverine systems, Journal of Soils and Sediments, 16(3), 1130-1144. 10.1007/s11368-015-1316-y
  18. Guzmán, G., Quinton, J.N., Nearing, M.A., Mabit, L., and Gómez, J.A., 2013, Sediment tracers in water erosion studies: current approaches and challenges, Journal of Soils and Sediments, 13(4), 816-833. 10.1007/s11368-013-0659-5
  19. Gyssels, G., Poesen, J., Bochet, E., and Li, Y., 2005, Impact of plant roots on the resistance of soils to erosion by water: a review, Progress in Physical Geography, 29(2), 189-217. 10.1191/0309133305pp443ra
  20. Heckmann, T., Cavalli, M., Cerdan, O., Förster, S., Javaux, M., Lode, E., Smetanová, A., Vericat, D., and Brardinoni, F., 2018, Indices of sediment connectivity: opportunities, challenges and limitations, Earth-Science Reviews, 187, 77-108. 10.1016/j.earscirev.2018.08.004
  21. Kardhana, H., Solehudin, Wijayasari, W., and Rohmat, F.I. W., 2024, Assessing basin-wide soil erosion in the Citarum watershed using USLE method, Results in Engineering, 22, 102130. 10.1016/j.rineng.2024.102130
  22. Kim, J.K., Onda, Y., Yang, D.Y., and Kim, M.S., 2013, Temporal variations of reservoir sediment sources in a small mountainous catchment in Korea, Earth Surface Processes and Landforms, 38(12), 1380-1392. 10.1002/esp.3379
  23. Latorre, B., Lizaga, I., Gaspar, L., and Navas, A., 2021, A novel method for analysing consistency and unravelling multiple solutions in sediment fingerprinting, Science of the Total Environment, 789, 147804. 10.1016/j.scitotenv.2021.147804
  24. Lim, Y.S., Kim, J.K., Kim, J.W., and Hong, S.S., 2014, Evaluation of suspended-sediment sources in the Yeongsan River using Cs-137 after major human impacts, Quaternary International, 344, 64-74. 10.1016/j.quaint.2014.05.033
  25. Mabit, L., Benmansour, M., Abril, J.M., Walling, D.E., Meusburger, K., Iurian, A.R., Bernard, C., Tarján, S., Owens, P.N., Blake, W.H., and Alewell, C., 2014, Fallout 210Pb as a soil and sediment tracer in catchment sediment budget investigations: A review, Earth-Science Reviews, 138, 335-351. 10.1016/j.earscirev.2014.06.007
  26. Marchi, L., Comiti, F., Crema, S., and Cavalli, M., 2019, Channel control works and sediment connectivity in the European Alps, Science of the Total Environment, 668, 389-399. 10.1016/j.scitotenv.2019.02.416
  27. Matisoff, G., 2014, 210Pb as a tracer of soil erosion, sediment source area identification and particle transport in the terrestrial environment, Journal of Environmental Radioactivity, 138, 343-354. 10.1016/j.jenvrad.2014.03.008
  28. Nyakatawa, E.Z., Jakkula, V., Reddy, K.C., Lemunyon, J.L., and Norris Jr, B.E., 2007, Soil erosion estimation in conservation tillage systems with poultry litter application using RUSLE 2.0 model, Soil and Tillage Research, 94(2), 410-419. 10.1016/j.still.2006.09.003
  29. Panagos, P., Borrelli, P., Meusburger, K., Alewell, C., Lugato, E., and Montanarella, L., 2015, Estimating the soil erosion cover-management factor at the European scale, Land Use Policy, 48, 38-50. 10.1016/j.landusepol.2015.05.021
  30. Potapov, P., Hansen, M.C., Pickens, A., Hernandez-Serna, A., Tyukavina, A., Turubanova, S., Zalles, V., Li, X., Khan, A., Stolle, F., and Harris, N., 2022, The global 2000-2020 land cover and land use change dataset derived from the Landsat archive: first results, Frontiers in Remote Sensing, 3, 856903. 10.3389/frsen.2022.856903
  31. Rixson, L., Aliyanta, B., Wenbiao, D., and Iman Sasmita, H., 2023, Behaviour of 137Cs and 210Pb inventory at three candidate reference sites for erosion study in the upstream Citarum watershed area, West Java, Indonesia, Isotopes in Environmental and Health Studies, 59(1), 78-99. 10.1080/10256016.2023.2169859
  32. Rixson, L., Wenbiao, D., Aliyanta, B., Godbold, D., Lubis, A.A., and Nugraha, E.D., 2024, Assessment of soil erosion in the Upper Citarum watershed for sustainability of the Saguling reservoir: unmixing model approach, Environmental Monitoring and Assessment, 196, 615. 10.1007/s10661-024-12750-8
  33. Salsabila, A., Sofiyah, and Kurniawan, T., 2023, Utilization of water hyacinth to reduce sedimentation and evapotranspiration in the Saguling reservoir by PT PLN Indonesia Power Saguling POMU, International Journal of Science and Society, 5(4), 27-37. 10.54783/ijsoc.v5i4.762
  34. Saputra, H., Dasanto, B.D., Tarigan, S.D., Santikayasa, I.P., and Darmawan, Y., 2026, Daily Rainfall Observations from 460 Stations and Flood Event Records across West Java, Indonesia (2020-2025), Mendeley Data, V3, doi: 10.17632/d7j3s64vvr.3 10.17632/d7j3s64vvr.3
  35. Satoshi, Y. and Katsushige, M., 2003, Development and application of sediment simulation system. in Dam Maintenance and Rehabilitation: Proceedings of the International Congress on Conservation and Rehabilitation of Dams, Madrid, 11-13 November 2002 (p. 389), Taylor and Francis.
  36. Schelske, C.L., Peplow, A., Brenner, M., and Spencer, C.N., 1994, Low-background gamma counting: applications for 210Pb dating of sediments, Journal of Paleolimnology, 10, 115-128. 10.1007/BF00682508
  37. Setiadi, S., Sumaryana, A., Bekti, H., and Sukarno, D., 2023, The flood management policy in Bandung city: Challenges and potential strategies, Cogent Social Sciences, 9(2), 2282434. 10.1080/23311886.2023.2282434
  38. Shi, Z.H., Cai, C.F., Ding, S.W., Wang, T.W., and Chow, T.L., 2004, Soil conservation planning at the small watershed level using RUSLE with GIS: a case study in the Three Gorge area of China, Catena, 55(1), 33-48. 10.1016/S0341-8162(03)00088-2
  39. Stone, M., Collins, A., Silins, U., Emelko, M., and Zhang, Y., 2014, The use of composite fingerprints to quantify sediment sources in a wildfire impacted landscape, Alberta, Canada, Science of the Total Environment, 473, 642-650. 10.1016/j.scitotenv.2013.12.052
  40. Teh, S.H., 2011, Soil Erosion Modeling Using RUSLE and GIS on Cameron Highlands, Malaysia for Hydropower Development, Master Thesis, University of Iceland, Reykjavik, Iceland.
  41. Walling, D.E., He, Q., and Quine, T., 1995, Use of caesium-137 and lead-210 as tracers in soil erosion investigation, in Leibundgut, C. (ed.), Tracer Technologies for Hydrological Systems, IAHS Publication No. 229, Wallingford: IAHS Press, 163-172.
  42. Walling, D.E. and He, Q., 1999, Using fallout lead-210 measurements to estimate soil erosion on cultivated land, Soil Science Society of America Journal, 63(5), 1404-1412. 10.2136/sssaj1999.6351404x
  43. Walling, D.E. and Woodward, J.C., 1992, Use of radiometric fingerprints to derive information on suspended sediment sources, in Bogen, J., Walling, D.E. and Day, T. (eds.), Erosion and Sediment Transport Monitoring Programmes in River Basins, IAHS Publication No. 210, IAHS Press, Wallingford, 153-164.
  44. Walling, D.E., He, Q., and Blake, W., 1999, Use of 7Be and 137Cs measurements to document short- and medium-term rates of water-induced soil erosion on agricultural land, Water Resources Research, 35(12), 3865-3874. 10.1029/1999WR900242
  45. Walling, D.E., 2005, Tracing suspended sediment sources in catchment and river systems, Science of the Total Environment, 344, 159-184. 10.1016/j.scitotenv.2005.02.011
  46. International Lake Environment Committee Foundation(ILEC), World lake database, https://wldb.ilec.or.jp/Display/html/3556
  47. InVEST, Integrated Valuation of Ecosystem Services and Tradeoffs, storage.googleapis.com/releases.naturalcapitalproject.org/invest-userguide/latest/en/sdr.html#sediment-delivery-ratio
Information
  • Publisher :The Korean Association of Regional Geographers
  • Publisher(Ko) :한국지역지리학회
  • Journal Title :REGION AND GEOGRAPHY
  • Journal Title(Ko) :지역과 지리
  • Volume : 32
  • No :3
  • Pages :189-214
  • DOI :https://doi.org/10.26863/JKARG.2026.8.32.3.189
Journal Informaiton REGION AND GEOGRAPHY REGION AND GEOGRAPHY
Journal Informaiton Journal Informaiton - close