*Ying Bai^1,2,3, Xiaohong Ruan^1,2, Jingwei Wu², Jan Peter van der Hoek³ (1.Key Laboratory of Surfacial Geochemistry, Administration of Education, Nanjing University, China, 2.School of Earth Sciences and Engineering, Nanjing University, China, 3.Delft university of Technology, Department of Water Management, 1, 2628 CN Delft, The Netherlands)