Evaluation of cadmium contamination due to bed load sediment transport in Mae Tao Creek, Mae Sot District, Tak Province, Thailand

The Mae Tao subcatchment is known as a site of grave concern in Thailand due to its cadmium contamination. High cadmium levels in bed load sediment are present; 33.93 mg/kg of cadmium was detected in bed load sediment downstream of the subcatchment. This research, therefore, concentrates on cadmium´s presence in bed load sediment and its transport throughout Mae Tao Creek. The stream flow during storm events at 10 monitoring stations along Mae Tao Creek were surveyed (the water discharge varied from 0.65 to 2.43 m³/s), and the cadmium concentration and grain size distribution of bed load sediment were quantified. The hydrodynamic results were simulated using MIKE SHE coupled with MIKE 11, and bed load sediment transport data were determined afterwards by the sediment transport module in MIKE 11. The sediment transport results and the measured cadmium concentration indicate that approximately 1.599 kg of cadmium was distributed out from the area in 2009.