About TopoDrive & ParticleFlow

History of Development

TopoDrive and ParticleFlow were developed by Paul Hsieh at the U.S. Geological Survey and were released in 2001. The original programs were written in the Java programming language, with the goal of running the programs inside web browsers as aplets. However, as browser technology changed over time, numerious hurdles arose with the use of Java technology for running programs in web browsers.

To create a new online version of TopoDrive and ParticleFlow, the programs were re-written in Javascript. This enables the programs to run in web browsers without the use of plugins.

About the Developer

Paul Hsieh is an independent groundwater hydrologist, having retired in 2018 from the U.S. Geological Survey after 41 years of service as a research hydrologist. He received a B.S.E. in Civil Engineering from Princeton University, and M.S. and Ph.D. in Hydrology and Water Resources from the University of Arizona.

His research at the USGS spanned over diverse topics that included groundwater flow and solute transport in fractured rocks, development and application of computer simulation models, interaction between groundwater and earthquakes, and volcano hydrology. During the 2010 Deepwater Horizon oil spill, he served on the federal government’s science team on oil spill response.

He is a Fellow of the Geological Society of America and the American Geophysical Union, and received a Service to America Medal in 2011 from the Partnership for Public Service.