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Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading
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Sediment: curse or blessing for Tonle Sap Lake?
Matti Kummu1, Dan Penny, Juha Sarkkula
1Water Resources Laboratory of Helsinki University of Technology, Finland. matti.kummu@iki.fi
Ambio
|July 4, 2008
Summary
Tonle Sap Lake is not rapidly filling its basin, contrary to claims. Sedimentation is low in the main basin but high at the margins, impacting nearby communities.
Area of Science:
- Hydrology
- Sedimentology
- Environmental Science
Background:
- Concerns exist about rapid sedimentation in Tonle Sap Lake due to increased catchment sediment yields.
- Potential impacts include altered flood dynamics in Cambodia and the Mekong Delta, and threats to the lake's ecosystem.
Purpose of the Study:
- To empirically assess current sedimentation rates in Tonle Sap Lake.
- To evaluate the implications of sedimentation for the lake and surrounding regions.
Main Methods:
- Radiocarbon dating of sediment cores to determine historical sedimentation rates.
- Hydrodynamic modeling to understand sediment transport and deposition patterns.
Main Results:
- Sedimentation rates within the main Tonle Sap Lake basin are low and have been for millennia.
- Sedimentation is significantly higher at the lake margins and within its floodplain.
Conclusions:
- The claim of rapid basin infilling is not supported by current data.
- High sedimentation at the margins and floodplain poses challenges for riparian communities.
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