Using high-resolution in situ radon measurements to determine groundwater discharge at a remote location: Tonle Sap Lake, Cambodia

  • W. C. Burnett
  • R. N. Peterson
  • S. Chanyotha
  • G. Wattayakorn
  • B. Ryan
Article

Abstract

Tonle Sap Lake (Cambodia) is the largest freshwater lake in SE Asia, and is reported to have one of the highest freshwater fish productions anywhere. During the dry season (November–April) the lake drains through a tributary to the Mekong River. The flow in the connecting tributary completely reverses during the wet monsoon (May–October), adding huge volumes of water back to the lake, increasing its area about fourfold. We hypothesize that nutrients are at least partially delivered via groundwater discharge, especially during the draining portion of the annual flood cycle. We surveyed over 200 km in the northern section of the lake using a customized system that measures natural 222Rn (radon), temperature, conductivity, GPS coordinates and water depth while underway. Results showed that there were portions of the lake with significant enrichments in radon, indicating likely groundwater inputs. These same areas were generally characterized by lower electrical conductivities. Samples collected from nearby wells also showed a general inverse relationship between radon and conductivity. Our data suggest that groundwater pathways are important, accounting for roughly 10–20 % of the freshwater flow of the Tonle Sap tributary (connection to the Mekong River), the largest single source of fresh water to the lake. Nutrient inputs from these inputs, because of higher concentrations in groundwater, will be correspondingly higher.

Keywords

Radon Tonle Sap Lake Groundwater discharge Remote locations Nutrients 

References

  1. 1.
    Lamberts D et al. (2007) In: 2nd international symposium on sustainable development in the Mekong River Basin, p 187Google Scholar
  2. 2.
    Kummu M, Penny D, Sarkkula J, Koponen J (2008) Ambio 37:158–163CrossRefGoogle Scholar
  3. 3.
    Sarkkula J, Koponen J, Kummu M et al. (2003) Final report to the Mekong River CommissionGoogle Scholar
  4. 4.
    MRC (Mekong River Commission) (2005) Overview of the hydrology of the Mekong Basin. Mekong River Commission, Vientiane (Laos), 73 pGoogle Scholar
  5. 5.
    Lamberts D (2006) Water Resour Dev 22:481–495CrossRefGoogle Scholar
  6. 6.
    Lamberts D (2008) In: M. Kummu M, Keskinen M and Varis O (eds) Modern myths of the Mekong, Water and Development Publications, Helsinki University of Technology, Helsinki, pp 3–18Google Scholar
  7. 7.
    Varis O, Kummu M, Keskinen M, Sarkkula J, Koponen J, Heinonen U, Makkonen K (2006) Tonle Sap Lake, Cambodia: nature’s affluence meets human poverty. Case study for 2006 HDR, pp 1–8Google Scholar
  8. 8.
    Junk WJ, Bayley PB, Sparks RE (1989) Can J Fish Aquat Sci 106:110–127Google Scholar
  9. 9.
    Junk WJ (1999) Arch Hydrobiol Suppl 115(3):261–280Google Scholar
  10. 10.
    Burnett WC, Kim G, Lane-Smith D (2001) J Radioanal Nucl Chem 249:167–172CrossRefGoogle Scholar
  11. 11.
    Dulaiova H, Peterson R, Burnett WC, Lane-Smith D (2005) J Radioanal Nucl Chem 263(2):361–365Google Scholar
  12. 12.
    Khattak NU, Khan MA, Shah MT, Javed MW (2011) J Radioanal Nucl Chem 290:493–505CrossRefGoogle Scholar
  13. 13.
    Lee KY, Yoon YY, Cho SY, Ko KS, Yum BW (2012) J Radioanal Nucl Chem. doi:10.1007/s10967-011-1608-7
  14. 14.
    Cable JE, Burnett WC, Chanton JP, Weatherly G (1996) Earth Planet Sci Lett 144:591–604CrossRefGoogle Scholar
  15. 15.
    Dulaiova H, Burnett WC, Chanton JP, Moore WS, Bokuniewicz HJ, Charette MA, Sholkovitz E (2006) Cont Shelf Res 26:1971–1983CrossRefGoogle Scholar
  16. 16.
    Dimova N, Burnett WC (2011) Limnol Oceanogr 56:486–494CrossRefGoogle Scholar
  17. 17.
    Dulaiova H, Burnett WC (2006) Geophys Res Lett 33:L05606. doi:10.1029/2005GL025023 CrossRefGoogle Scholar
  18. 18.
    Burnett WC, Cable JE, Corbett DR (2003) In: Taniguchi M, Wang K, Gamo T (eds) Land and marine hydrogeology. Elsevier, Amsterdam, pp 25–43CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2012

Authors and Affiliations

  • W. C. Burnett
    • 1
  • R. N. Peterson
    • 2
  • S. Chanyotha
    • 4
  • G. Wattayakorn
    • 3
  • B. Ryan
    • 5
  1. 1.Department of Earth, Ocean and Atmospheric SciencesFlorida State UniversityTallahasseeUSA
  2. 2.Center for Marine and Wetland StudiesCoastal Carolina UniversityConwayUSA
  3. 3.Department of Marine Science, Faculty of ScienceChulalongkorn UniversityBangkokThailand
  4. 4.Department of Nuclear Engineering, Faculty of EngineeringChulalongkorn UniversityBangkokThailand
  5. 5.Department of Sustainability, Environment, Water, Population and CommunityCanberraAustralia

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