Trained as a geographer, I have been working on an interdisciplinary area, spatial epidemiology. I developed a conceptual framework, Epidemic Forest or Epi-Forest, for spatiotemporally modeling communicable diseases. Different from traditional epidemic modeling, Epi-Forest adopts a "bottom-up" approach that models the disease transmission at the individual level and thus incorporates precise spatial and temporal information. I first developed Epi-Forest in a study of Dengue Fever, and then applied it to the recent COVID-19 pandemic. The applications of this approach in Nanchang City and Sichuan Province, China, have been recognized by the local government and researchers to be effective. Besides communicable diseases, my research also concerns environmental health related to cancers and neurological diseases (e.g., ALS). I am particularly interested in the geocomputational approach (intensive computation on big data) to mapping diseases and detecting disease-environmental associations.