In May, 1999 the Sixth World Conference was held at Izumisano, Osaka, Japan. This conference was the first big event of the International Society for Neutron Radiology. Ninety five participants from eighteen countries came together at the conference, where eighty three papers were presented in oral session, including four lectures titled as "Neutron Radiography: Status of the Art and Future" with simultaneous translation in Japanese and English. There was also a poster session, and a panel discussion titled as "Future of Neutron radiography Research."
In this volume, eighty one papers including four lecture notes and four review papers are grouped into fourteen chapters. This volume of the proceedings is the sixth one of the series of the World Conferences.

Dr Peter Downs is currently Senior Fluvial Geomorphologist at Stillwater Sciences, Berkeley, California. He has taught and researched extensively on geomorphological applications to river channel management and restoration.

Professor Ken Gregory is currently Visiting Professor, University of Southampton and Emeritus Professor, University of London. He was awarded the Founders Medal of the Royal Geographical Society for research on river channels. He is the author of Palaeohydrology: Understanding Global Change (Wiley, 2003) and The Changing Nature of Physical Geography (Arnold, 2000).