This report investigates how much water is required to maintain the freshwater reed beds that are the main shelter and breeding place for threatened bird species. The ability of Gediz basin to fulfill this requirement and the effects of this requirement on irrigated agriculture, the major competitor for water in the Gediz basin were subsequently examined.
The intention of this paper is to develop a framework for a new IWMI research program on environmental water requirements of aquatic ecosystems and environmental aspects associated with irrigated agriculture in river basins and wetlands. The program will be implemented primarily in the context of developing countries, but the paper also examines research questions, which are of general importance for eco-hydrology and environmental water resources management. At the same time, it does not purport to be a comprehensive coverage of the environmental water research field but is designed primarily for attention of specialists dealing with wetlands, water resources management and sustainable agricultural development within sister CGIAR centers and other similar international agencies. It is envisaged that some ideas for future research presented in the paper will also be of interest to hydrologists and ecologists engaged in developing the concepts of environmental water requirements of aquatic ecosystems. The introduction of the paper sets up the purpose of the document. This is followed by a description of a framework, which links different levels of water resources use and conservation of natural aquatic systems with various management interventions. The main focus areas of the proposed research are then discussed. They include estimating water requirements of aquatic ecosystems, evaluating scenarios of development and impacts of irrigated agriculture on rivers and wetlands, allocating water with the consideration of environmental thresholds, etc. The paper also discusses possible research activities, which are associated with these focus areas and presents examples of specific research projects that could be pursued internally or in partnership with other national and international institutions.
Describes the use of a distributed hydrologic model to evaluate different data scenarios. The study attempted to answer questions such as; what will happen to the basin water resources if a) there is a change in climate; b) it is decided that more water must be retained in the river for environmental reasons; c) more water is extracted for urban and industrial use; d) the timing and accounts used for water are changed?
This volume is an analytical summary and a critical synthesis of research at the International Water Management Institute over the past decade under its evolving research paradigm known popularly as 'more crop per drop'. The research synthesized here covers the full range of issues falling in the larger canvas of water-food-health-environment interface. Besides its immediate role in sharing knowledge with the research, donor, and policy communities, this volume also has a larger purpose of promoting a new way of looking at the water issues within the broader development context of food, livelihood, health and environmental challenges. More crop per drop: Revisiting a research paradigm contrasts the acquired wisdom and fresh thinking on some of the most challenging water issues of our times. It describes new tools, approaches, and methodologies and also illustrates them with practical application both from a global perspective and within the local and regional contexts of Asia and Africa. Since this volume brings together all major research works of IWMI, including an almost exhaustive list of citations, in one single set of pages, it is very valuable not only as a reference material for researchers and students but also as a policy tool for decision-makers and development agencies.
Over-pumping of aquifers is a worldwide problem, mainly caused by agricultural water use. Among its consequences are the falling dry of streams and wetlands, soil subsidence, die-off of phreatophytic vegetation, saline water intrusion, increased pumping cost and loss of storage needed for drought relief. Stopping or reversing the trend requires management interventions. The North China Plain serves as an example. A management system is set up for a typical county. It contains three components: monitoring, decision support based on modelling, and implementation in the field. Besides all monitoring data, the decision support module contains an irrigation calculator, a box model, and a distributed groundwater model to project the outcomes of different water allocation scenarios. In view of grain security, a solution combines an adaptation of the cropping system with imports of surface water from the South. The Open Access book does not only describe the problem and the path to its solution. It also gives access to nine manuals concerning methods used. They include computer programs and the game Save the Water. The Chinese experience should be of considerable interest to other regions in the world which suffer from over-pumping of aquifers.
Jan van Schilfgaarde, USDA Agricultural Research Service and National Research Council Committee on Irrigation-Induced Water Quality Problems In 1982, a startling discovery was made. Many waterbirds in Kesterson National Wildlife Refuge were dying or suffering reproductive failure. Located in the San Joaquin Valley (Valley) of California, the Kesterson Reservoir (Kesterson) was used to store agricultural drainage water and it was soon determined that the probable cause of the damage to wildlife was high concen trations of selenium, derived from the water and water organisms in the reservoir. This discovery drastically changed numerous aspects of water management in California, and especially affected irrigated agriculture. In fact, the repercussions spilled over to much of the Western United States. For a century, water development for irrigation has been a religiously pursued means for economic development of the West. The primary objective of the Reclamation Act of 1902 was, purportedly, the development ofirrigation water to support family farms which, in turn, would enhance the regional economy (Worster, 1985).
There is an estimated 1.4 billion km3 of water in the world but only approximately three percent (39 million km3) of it is available as fresh water. Moreover, most of this fresh water is found as ice in the arctic regions, deep groundwater or atmospheric water. Since water is the source of life and essential for all life on the planet, the use of this resource is a highly important issue. "Water management" is the general term used to describe all the activities that manage the optimum use of the world's water resources. However, only a few percent of the fresh water available can be subjected to water management. It is still an enormous amount, but what's unique about water is that unlike other resources, it is irreplaceable. This book provides a general overview of various topics within water management from all over the world. The topics range from politics, current models for water resource management of rivers and reservoirs to issues related to agriculture. Water quality problems, the development of water demand and water pricing are also addressed. The collection of contributions from outstanding scientists and experts provides detailed information about different topics and gives a general overview of the current issues in water management. The book covers a wide range of current issues, reflecting on current problems and demonstrating the complexity of water management.
In many places, growing population, in conjunction with efforts to increase food security, is escalating pressure to expand agriculture within wetlands. The environmental impact of wetland agriculture can have profound social and economic repercussions for people dependent on ecosystem services other than those provided directly by agriculture. If wetlands are not used sustainably, the functions which support agriculture, as well as other food security and ecosystem services, are undermined. This report synthesizes findings from multidisciplinary studies conducted into sustainable wetland agriculture by IWMI and partners in Africa and Asia. It highlights the value of wetland agriculture for poverty reduction as well as the need for more systematic planning that takes into account trade-offs in the multiple services that wetlands provide.
Capturing information from 27 OECD countries and key partner economies, the report presents key findings from the OECD Survey of Water Resources Allocation and case studies of successful allocation reform.
