Spatial distribution of 137Cs in surface soil under different land uses in Chao Phraya watershed: Potential used as sediment source tracing

International Nuclear Science and Technology Conference 2014

Srisuksawad, K.^1 ; Porntepkasemsan, B.^1 ; Noipow, N.^1 ; Omanee, A.^1 ; Wiriyakitnateekul, W.^2 ; Chouybudha, R.^2 ; Srimawong, P.^2

Thailand Institute of Nuclear Technology, Nakhon Nayok

26120, Thailand^1

Land Development Department, Bangkok

10900, Thailand^2

关键词: Fallout radionuclides;    Geospatial interpolations;    Limit of detection;    Relative contribution;    River catchment;    Sediment fingerprinting;    Sediment sources;    Spatial concentration;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/611/1/012026/pdf
DOI  :  10.1088/1742-6596/611/1/012026

来源: IOP

【 摘 要 】

Sediment fingerprinting techniques involves the discrimination of sediment sources based on differences in source material properties and quantification of the relative contributions from these sources to sediment delivered downstream to the river catchments. Results of the previous study indicated that fallout radionuclides (FRNs);137Cs and excess210Pb (210Pbex) are the most suitable radionuclides to be used as sediments sources tracers. This study investigated the spatial distribution of137Cs in soil under different land uses in Chao Phraya watershed; the most significant watershed in Thailand. Emphasis was placed on discriminating among potential sediment sources including the cultivated (upland crops), pasture field, uncultivated (swamp, forest, and grass field), and channel erosion (stream and river bank). One hundred and twenty four soil samples were collected from all sources and determining for137Cs. The137Cs mass activities in pasture areas varied from the limit of detection (LLD) to 1.22±0.05 with the average of 0.64±0.14 Bq kg-1. In cultivated areas the137Cs mass activities varied from LLD to 1.41±0.04 with the average of 0.38±0.04 Bq kg-1. The137Cs mass activities were higher in uncultivated areas varied from 0.12±0.03 to 1.73±0.05 with the average of 0.76±0.15 Bq kg-1. The137Cs mass activities in channel bank varied from LLD to 1.16±0.04 with the average of 0.39±0.05 Bq kg-1.GIS and geospatial interpolations revealed pattern in the spatial concentrations of137Cs and indicated important differences in its distributions showing the differences behaviour of137Cs in different land uses.