Dr. An Zhang is a Visiting Scholar at the Center for Geographic Analysis, Harvard University. He is an Associate Professor Professor from the Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Science. His main research interest is demography and public health study based on Geographical Information System. He is particularly focused on the study of dynamic population estimation model and public health spatiotemporal analysis. He will work with Prof. Peter Bol on the spatial and temporal analysis of China's Census and physical geographical features during his visit to the CGA.