Spatial and temporal distribution of heavy metals in sediment cores form the upper Chao Phraya watershed | |
| Author | Piyarattana Homyok |
| Call Number | AIT Thesis no.EV-20-09 |
| Subject(s) | Heavy metals--Environmental apects--Thailand--Chao Phraya watershed Sediments (Geology) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | The Upper Chao Phraya Watershed plays important rules in the social and economic development in Thailand. Until recently, however it is experiencing fast urbanization and rapid socioeconomic development since over the past 70 years. This study investigated the spatial and temporal variations of selected heavy metals (As, Cr, Cd, Cu, Hg, Pb, Zn, and Ni) in sediment cores from the upper Chao Phraya Watershed, evaluated pollution load and assessed the factors affecting these sediment cores through multivariate statistical and stepwise multiple linear regression analysis. The results demonstrated that the highest pollution load was found in upstream more than downstream of Wang sub-watershed and followed by Yom, Nan, and Ping sub-watersheds, respectively. Temporally, the pollution load in Wang 2 shows decreasing trend in past 30 years due probably to the introduction of the environmental pollution policies of main power plant in 1995 On the other hand, Wang 1 which shows an increasing trend due probably to agricultural activities and urbanization in the sub-watershed. The decrease in upland agriculture resulted in the decrease of the pollution load in Nan 1. On the contrary, the pollution load in Yom 2, Ping 2, and Ping 3 was found have increased over the past 30 years duo to the increasing intensity of urbanization and agriculture activities to meet the increasing growing population. Additionally, the result of principle component analysis indicated that Cu, Zn, As explained 40.09 % of the metal loading in sediment cores, followed by Cr, Ni, Hg (26.04 %), and Cd, Pb (15.31 %), respectively. They represented the contributions from agriculture, natural mineral and urban sources, respectively. Through the analysis of the factors potentially affecting these loads, this study found that final energy consumption and Gross provincial product per capita in the sub-watershed have positive and negative correlation with the most of metal loadings in downstream sediment cores, respectively (pvalue < 0.001). Moreover, land use patterns in sub-watershed scale showed significant correlation to all studied metals and pollution load index (PLI) with p-value < 0.001. In particular, urban land use showed positive correlations to most of the investigated metals. This study concludes that agricultural, natural mineral and urban sources are the main sources of polluted sediment cores, while energy consumption affects the sediment load. |
| Year | 2020 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Xue, Wenchao; |
| Examination Committee(s) | Ekbordin Winijkul;Sasaki, Nophea; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2020 |