Integrated spatial approaches for long-term monitoring of cadmium contamination caused by rainfall erosion: A case study of overland sediment in Mae Sot, Thailand

Abstract

© 2020 Mae Tao basin, Thailand has been reported as a remote cadmium (Cd) - contaminated area from 2002 to 2016 and a declaration on the contaminant source has not been accomplished. Howbeit, the determination of contaminant sources transmitted by overland flow is generally limited by various kinds of factors, data insufficiency in particular. In this study, the integrated spatial technology between remote sensing, digital mapping, GIS, and RUSLE were used to conduct the approach in deciding the source of contamination in the basin. According to the results, the significant anthropogenic activity which can release the highest cadmium's level was determined as the cornfield in the upstream. With the potential cadmium flux from erosion ranged from 279.86 to 703.73 t/ha/year and 0.77 correlation factor to the cadmium contamination level in the creeks, the soil surface and corn collected from the upstream were investigated using FAAS and Micro XRF for validation. The cadmium transported by upstream soil surface may not affect the Cd contamination in the downstream so that the contamination's source be from other anthropogenic activities. As a result, this integrated method demonstrates a capability in applying this set of applications to monitoring, investigating and managing contaminant sources in a remote area.