Zhen Tan^1,2, Qiang Yang³, Kongkea Phan⁴, Benjamin C Bostick³ and Yan Zheng^1,3, (1)Southern University of Science and Technology, School of Environmental Science and Engineering, Shenzhen, China, (2)Peking University, Institute of Water Sciences, Beijing, China, (3)Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, United States, (4)International University, Faculty of Science and Technology, Phnom Penh, Cambodia