From 1984-1990, John was an Assistant Professor in the School of Forest Resources at UGA. After a year at the University of Plymouth (southwest England), he moved to this department. He has maintained links with the School of Forest Resources, co-teaching several joint-listed courses with Todd Rasmussen.
US based research: He has been involved with a number of projects in Georgia and the southeast. These include database studies for the Park Service, and various projects at the J. Phil Campbell Sr. Natural Resources Conservation Center, Agricultural Research Service (ARS) in Watkinsville, Ga. Studies at the ARS include kinematic rainfall generation, deep vadose zone sampling, 3-D groundwater flow modeling, and network modeling of flow paths to derive a geomorphologic instantaneous unit hydrograph. Studies at other locations have included the investigation of the hydraulic properties and solute transport in saprolite, flow and transport in fractured bedrock, and the fate and transport in the environment of various pesticides. Many of these studies have utilized stable isotopes as naturally occurring tracers.
England based research: He has been a Senior Visiting Fellow at the University of Plymouth where he was involved in several research projects concerning flow and transport in the vadose zone, and rainfall-runoff relations. One project involved measuring and modeling water and tracer movement in a structured soil using a large in situ soil block. The elaborate computer-controlled collection devices were initially developed at Georgia. Other British-based research includes modeling a large wetland in Cornwall, investigating flow in mole drains at the Institute for Grassland and Environmental Research (IGER), and plot and catchment-scale studies at a small experimental catchment on Dartmoor called Holne Moor. Some of the Holne Moor results are summarized at http://www.plymouth.ac.uk/pages/view.asp?page=18534.