Dr. Katsuhide Yokoyama is a Professor and the head of the Environmental Hydraulics Laboratory in the Department of Civil and Environmental Engineering at Tokyo Metropolitan University. He finished his Master’s and Doctorate degrees at the Tokyo Institute of Technology. He is currently working on several research projects centered on erosion and sediment production processes in a watershed, hydrodynamics in a drinking water reservoir, saltwater mixing, sediment transport, phytoplankton distribution, and morphodynamics in estuaries, and the restoration of tsunami-affected salt marshes and tidal flats.