This volume contains the papers of invited lectures presented at the Memorial Colloquium on Environmental Fluid Mechanics, held on June 3 and 4, 2011, in Karlsruhe, Germany in honour of the late Professor Gerhard H. Jirka, who passed away unexpectedly in February 2010. With both the colloquium and this volume the colleagues of Professor Jirka would like to commemorate and pay tribute to his great body of work and achievements in the area of Environmental Fluid Mechanics. This discipline is of considerable, fundamental interest in our society and represents the scientific and applied study of fluid motion and its implications for the transport and distribution of mass and heat in natural and man-affected systems in the environment. The volume contains invited contributions from the most prominent experts in the field worldwide, all of them motivated by their appreciation and recognition of the work of Prof. Jirka. The contributions can be divided into the following sub-areas: Fluvial Hydraulics, Shallow Flows, Buoyant/Stratified Flows, Gravity Currents, Mass Transfer, and Small-Scale Phenomena. A paper summarizing the scientific work and achievements of Prof.
Jirka heads off the volume.