Sedimentation Problems In River Basins

Influence of man's activities on sedimentation processes; Erosion and sedimentation processes; The prediction of the effects of man's activities; Methods to control erosion and sedimentation; Case studies.

This volume, arising from a workshop organised jointly by the International Commission on Continental Erosion (ICCE) of IAHS, the UNESCO International Sediment Initiative (ISI) and the World Association for Sedimentation and Erosion Research (WASER), focuses on sediment problems in Asian river basins and the many difficulties involved in their effective management. The first section comprises overviews of the sediment problems experienced by individual countries or particular issues relating to the wider region; and the second documents case studies that deal with specific problems and their management. The overviews highlight the sediment problems faced by India and Iran, including soil erosion and reservoir sedimentation; recent changes in the sediment loads of the Hindu Kush-Himalayan rivers and their wider implications; the impact of human activity on the sediment loads of Asian rivers; and new challenges for erosion and sedimentation research in China linked to contemporary issues.

Reservoir Sedimentation: Assessment and Environmental Controls appraises the issues of sedimentation in reservoirs and discusses measures that can be employed for the effective management of sediment to prolong the operational life of reservoirs. It provides information for professional consultants and policymakers to enable them to manage dams in the best possible way, in order to ensure their sustainability as well as the sustainability of water resources in general. It examines the effects of anthropogenic intervention and management of sediment in dams and reservoirs, as water resources become more sensitive and the demand for clean water continues to increase. Features: Examines the issue of sedimentation in dams and reservoirs and presents water management strategies to alleviate environmental issues Presents methods to help ensure the environmental sustainability of dams and reservoirs, as well as the sustainability of water resources- with consideration of climate change and increased demand Illustrates the spatial distribution of sedimentation characteristics for several dams using geographic information systems (GIS) Explains the relationships between loss in capacity and catchment characteristics Examines regional variation in sediment yield, defines geomorphic regions on the basis of similar hydrometeorology, physiography, geology, and vegetation affecting reservoirs

Sediments, which constitute the surface of the Earth, start their journey to rivers with the energy obtained from rainfalls, fl oods and other natural processes. Due to transport of sediments, rivers develop with various appearances and functions, and play a crucial role in the activities of human beings and the life cycles of other species. River

This book presents insights into the complex processes controlling sediment behavior in river basins and into state of the art integrated sediment management concepts. Main topics are: sediment transport, modelling sediment transfer in rivers, sediment quality, sediment monitoring and integrated sediment management at catchment scale. Interlinkages of sediment dynamics and quality with biogeochemistry, ecology, climate change and human activities are discussed. Drivers, boundary conditions and processes of erosion, sediment transport and sedimentation are presented with the aim to help the reader putting sediment quantity and quality issues into perspective.

Research on reservoir sedimentation in recent years has been aimed mainly at water resources projects in developing countries. These countries, especially in Africa, often have to cope with long droughts, flash floods and severe erosion problems. Large reservoir capacities are required to capture water provided by flash floods so as to ensure the supply of water in periods of drought. The problem arising however is that these floods, due to their tremendous stream power, carry enormous volumes of sediment which, due to the size of reservoirs, are virtually deposited in toto in the reservoir basin, leading to fast deterioration of a costly investment. Accurate forecasting of reservoir behaviour is therefore of the utmost importance. This book fills a gap in current literature by providing in one volume comprehensive coverage of techniques required to practically investigate the effects sediment deposition in reservoirs has on the viability of water resources projects. Current techniques for practically estimating sediment yield from catchments, estimating the volume of sediment expected to deposit in reservoirs, predicting sediment distribution and calculating scour downstream of reservoirs are evaluated and presented. The liberal use of diagrams and graphs to explain the various techniques enhances understanding and makes practical application simple. A major feature of the book is the application of stream power theory to explain the process of reservoir sedimentation and to develop four new methods for predicting sediment distribution in reservoirs. The book is primarily directed at practising engineers involved in the planning and design of water resources projects and at post-graduate students interested in this field of study.