It is becoming acknowledged that water is likely to be the most pressing environmental concern of the next century. Difficulties in river basin management are only exacerbated when the resource crosses international boundaries. One critical aid in the assessment of international waters has been the Register of International Rivers a compendium which listed 214 international waterways that cover 47% of the earth's continental land surface. The Register, though, was last updated in 1978 by the now defunct United Nations Department of Economic and Social Affairs. The purpose of this paper is to update the Register in order to reflect the quantum changes that have taken place over the last 22 years, both in global geopolitics and in map coverage and technology. By accessing digital elevation models at spatial resolutions of 30 arc seconds, corroborating at a unified global map coverage of at least 1:1 000 000, and superimposing the results over complete coverage of current political boundaries, we are able to...

International River Basins of the World

The International Food Policy Research Institute (IFPRI) was established in 1975 to identify and analyze national and international strategies and policies for meeting the food needs of the developing world on a sustainable basis, with particular emphasis on low-income countries and on the poorer groups in those countries. IFPRI is a member of the CGIAR Consortium. This Report has been prepared as an output of the International Model for Policy Analysis of Agricultural Commodities and trade (IMPACT). While the report has not been peer reviewed, the IMPACT model has undergone peer review. Any options stated herein are those of the author(s) and do not necessarily reflect the policies or opinions of IFPRI. Figure 1 Statistical distribution of soil water-holding capacity and runoff generation in a grid cell ..

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International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) Model Description

Pricing irrigation water: a review of theory and practice

The challenge for agriculture over the coming decades will be to meet the world's increasing demand for food in a sustainable way. Declining soil fertility and mismanagement of plant nutrients have made this task more difficult. In this brief, Peter Gruhn, Francesco Goletti, and Montague Yudelman point out that as long as agriculture remains a soil-based industry, major increases in productivity are unlikely to be attained without ensuring that plants have an adequate and balanced supply of nutrients. They call for an Integrated Nutrient Management approach to the management of plant nutrients for maintaining and enhancing soil, where both natural and man-made sources of plant nutrients are used. The key components of this approach are described; the roles and responsibilities of various actors, including farmers and institutions, are delineated; and recommendations for improving the management of plant nutrients and soil fertility are presented.

Integrated nutrient management, soil fertility and sustainable agriculture: current issues and future challenges

http://directory.umm.ac.id/Data%20Elmu/jurnal/A/Agricultural%20Water%20Management/Vol45.Issue3.Aug2000/1556.pdf

Nutritional water productivity and diets

Global food projections indicate that food prices in the next threedecades will likely be stable or decline, but progress inreducing malnutrition in developing countries will be slow. Smallshortfalls in crop productivity growth would lead to rising foodprices and worsening malnutrition. Increased food production fromirrigation is essential, and will require expansion of irrigatedarea and water supplies, and improved efficiency of use of existingwater supplies. Neither of these growth factors will prove easy, andboth will require complex institutional and policy reforms. Failureto meet food production needs through efficient expansion andintensification of irrigated agriculture would increase pressure onland resources and hasten the process of environmental degradation.Irrigation and water development strategies have been hampered bya lack of understanding of the links between water scarcity, foodproduction, food security, and environmental sustainability.Research to improve this understanding would have high payoffs.

David Seckler

Papers

Irrigation and food security in the 21st century