Lam Phra Phloeng dam, Nakhon Ratchasima province, is one of the dams most seriously affected by soil erosion related sedimentation in Thailand. Deforestation and rapid land use change, from forest to agricultural land, has led to increase sediment load in rivers draining into the dam. The dominant crops in the upper catchment are sugar-cane and cassava. After the crop has been harvested the land is tilled and becomes sensitive to sheet erosion. As a direct result the dam has become very shallow and its storage capacity was reduced rapidly. In this study, the constant initial concentration (CIC) of unsupported 210Pb model was successfully used to assess sedimentation rate from 210Pb profile data of eight sediment cores from Lam Phra Phloeng dam. The 210Pb based apparent sediment accumulation rates ranged from 0.21 to 1.02 g/cm2/yr with the average of 0.51 g/cm2/yr compatible to the total sediment loaded to the river of 5.491´104 metric ton/yr and corresponding to the erosion rate of 2.27 mm/yr. More than 50% of the sediment was deposited at the distance of 3-5 km. from the head of the reservoir. Such sediment distribution behavior was described based on the direction and velocity of the stream current. This study thus demonstrated the potential use of nuclear technique for water resource and erosion control management.
Kanitha Srisuksawad, Thailand Institute of Nuclear Technology, Thailand
This paper is part of the ACSEE2013 Conference Proceedings (View)
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