Abstract:
The Southwest monsoon and the Norteast monsoon mainly controls climate and its circulation related with change in wind and precipitation pattern over Thailand. Changes in this convectively active region can result in severe drought or flood over large regions. Lake sediment is one of geological archives which have potential to reconstruct past monsoon intensity. Then, this research aims to study the relationship between Asian monsoon, geographical feature, paleogeographical and paleoenvironment of Nong Han Kumphawapi. The investigate of physical and chemical properties of lake sediment, and the measurement of AMS ¹⁴C radiocarbon dating were made at Nong Han Kumphawapi, Udon Thani Province. Sediment cores were collected by a Russian corer (chamber Ø: 10 cm and 7.5 cm, chamber length: 1 m) and with 0.5 m overlap. The coring point’s co-ordinates were identified by GPS to improve the accuracy of sediment cores’ position. The most complete sequence (CP3A) was selected for high-resolution multi-proxy sub-sampling in the laboratory. Magnetic Susceptibility (MS), X-ray fluorescence (XRF), Loss-on-ignition method (LOI) and AMS ¹⁴C dating were use in the sediment cores analysis. In addition, we combine the data from aerial photos interpretation and GIS based map in order to investigate geographical feature and paleogeographical. The results show that the oldest sediment sample is around 7,763 cal years B.P. and the youngest sample dates to around 436 cal years B.P. In conclusion,the sediment and the combined proxy data indicate that Nong Han Kumphawapi underwent several phases with higher/lower lake levels, which potentially could be related to changes in monsoon intensity.
