Originally published in 1982, this book presents a detailed review of alluvial river form and process and integrates the distinct but related approaches of geomorphologists, geologists and engineers to the subject. It outlines the environmental catchment factors that control the development of channel equilibrium and provides a detailed account of the sediment transport processes that represent the physical mechanisms by which channel adjustment occurs. Where possible it evaluates theoretical analyses in the context of the empirical evidence. Rivers should prove a valuable textbook for geomorphology students on advanced undergraduate courses on river behaviour and will also be of interest to students of hydraulics and sedimentology and to those concerned with civil and environmental engineering, river management and channel design, maintenance and management in the water industry
Dams or barriers are among the most significant anthropogenic threats to global freshwater ecosystems, although they provide invaluable services for shipping, hydropower generation, flood protection, and storage of drinking and irrigation water. River fragmentations due to dams and barriers lead the aquatic landscape into isolated river sections, resulting in hydromorphological discontinuities along longitudinal or lateral gradients. Fragmented river habitats are unstable. They experience uncertain disturbances in both time and space with random and complex hydrological and environmental processes, such as water flow, particulate matter sedimentation, reservoir regulation, and terrestrial input. The diversity, composition, functionality, and activity of microbial communities are important indicators of river ecosystem functions and services. Yet, river fragmentations are likely to disrupt and reconstruct microbial communities, redirecting the patterns of biogeochemical cycles of biogenic elements. Methodology, such as mathematical models, is still limited to describing and elucidating microbial processes under changing hydrological environments in the fragmented rivers. Thus, how do the riverine microbial communities and ecosystem functions respond to the fragmentation in rivers? This Research Topic represents a collective focus on microbial ecology, functional diversity, and new microbial modeling in fragmented rivers. We wish to present new findings in community assembly mechanisms, biotic interactions, functional diversity, and ecosystem functioning responses to the river fragmentations. New perspectives will also provide us with deep insights into the ecological effects of river fragmentation. This Research Topic aims to present the original research articles and reviews to provide new findings on microbial diversity and ecosystem functioning in fragmented rivers worldwide. We welcome original research, reviews, mini-reviews, opinions, methods, hypotheses and theories, and perspectives. The directions include but are not limited to the following aspects: - The continuum of the microbial community in responses to dams or barriers. - Novel microbial community assembly mechanisms, functional traits, and biotic interactions in fragmented rivers at local, regional, and global scales. - Functional genes, functional groups, and functional diversity in driving biogenic element cycles. - Mathematical modeling in aquatic microbial ecology.
This book addresses basic questions concerning the ecological relationships and current conditions of the major river systems in Florida . . There have been relatively few comprehensive studies made of the rivers of Florida. There is, to be sure, voluminous information that addresses various aspects of riverine ecology. However, little such information has been collected in a way that allows even a preliminary understanding of the driving forces that determine how the diverse freshwater and associated brackish systems function. This lack of useful data is the product of a fundamental ignorance concerning the scale of endeavor, both spatially and temporally, that is needed if we are to understand and, parenthetically, manage the major drainage systems of this area of the country (Livingston, 1987). Research used to address management problems should entail a continuous series of interrelated studies, descriptive and experimental, that answer the immediate (and often less important) questions that are asked on a day-to-day basis. The research should also be designed to answer questions that have not yet been asked. In other words, ecosystem research should be organized on an appropriate scale so that system-wide processes are understood and pr
Follows the Colorado River's 1450-mile journey from its headwaters high in the Colorado Rockies to its dried-up delta touching the Sea of Cortez, discussing its historical, geographical, and environmental significance.
