ABSTRACT
Humankind relies on rivers for an array of functions including biodiversity and conservation, irrigation, and domestic or industrial water supply. Providing flows for biota and environmental processes is a challenging water management issue. For society, the ability and readiness to allocate water to sustain the environment is increasingly competitive due to the rising demand and as a consequence of climate change. Environmental flows are defined as the discharge of water in streams and rivers, necessary to sustain aquatic ecosystems, and human communities depend on them. The assessment and provisioning of environmental flows are an important component of integrated water resources management to ensure the sustainability of vital aquatic ecosystems.
332This chapter provides a comprehensive study on environmental flows concept. Following in this chapter, an overview of the ecosystem characteristics of the rivers focusing on their natural flow regimes is provided, followed by a description of the ecosystem services of rivers in relation to their flow regimes. This chapter briefly provides the background for environmental flows concept and history. Next it discusses various methods of environmental flows assessment. Finally, it concludes with a few key issues on the need for research on the incorporation of environmental flows requirements in planning, implementation, and monitoring of water resources development projects.
