to develop under quasi-stable conditions in an alluvial channel: for example, patterns of response to tectonic activity longitudinal variations in channel and floodplain form associated with spatially varying patterns of bedrock lithology or jointing arid region rivers with longitudinal discharge trends that are not mono-tonically increasing. Also of potential interest are morphological features forming under climatic/hydrologic regimes associated with monsoon, tropical wet, extremely arid or extremely cold environments; or patterns of vegetation distribution that exert a controlling influence on channel form. It is hoped that the papers contributed to this session will encompass a broad range of geographic as well as morphological diversity. The underlying premise was that the worlds rivers encompass a wide range of influences and associated fluvial forms, but that the geomorphic literature traditionally has focused most intensively on a subset of those forms (mostly comprised of alluvial rivers from humid temperate, semiarid orproglacial environments), and may not treat a spectrum of morphological types that is proportionately representative of the rivers that actually exist on the earths surface. Thus the intention of this volume is, first and foremost, to present an international set of case s