Asian Water Supplies Require Substantial Overhaul

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China irrigationAsian countries urgently need to boost farmland productivity and use water more efficiently or the continent may not have enough water to support the agricultural needs of its growing populations, an Asian Development Bank-supported study found.

Dwindling groundwater supplies are already threatening drinking water and crop production across Asia. Undeveloped arable land, meanwhile, is in short supply. As a result, Asian countries will have to import more food or improve irrigation methods, the UN Food and Agriculture Organization (FAO) and International Water Management Institute (IWMI) concluded in a report [PDF] released today.

"Relying on trade to meet a large part of this demand will impose a huge and politically untenable burden on the economies of many developing countries," said Colin Chartres, director general of IWMI, a Sri Lanka-based research organization, in a statement. "The best bet for Asia lies in revitalizing its vast irrigation systems, which account for 70 percent of the world's total irrigated land."

About 5 billion people are projected to live in Asia by 2050. With demand for meat products on the rise, experts estimate that the region must double its supplies of food and animal feed crops during the next 50 years to feed an additional 1.5 billion people.

If population projections are borne out, food demands by 2050 would require South Asia to irrigate 30 percent more harvested land. These new farms would demand 57 percent more water unless water efficiency improves. In East Asia, farmers would need to increase the amount of irrigated farmland by 47 percent, at the cost of a 70-percent increase in water use, the study said.

The study did not factor in the effects of climate change, even though irrigation demands in arid and semi-arid parts of Asia are expected to rise as global temperatures increase. Scientists forecast that climate change will cause reduced flow in many Asian rivers as the Himalayan glaciers recede. Noting the absence of climate modeling in their projections, the report authors said "the study's pessimistic assumptions may prove overly optimistic."

The researchers emphasize, however, that efforts to modernize Asian irrigation schemes would help adapt to a warmer climate and feed a growing population. In Asia, particularly in South Asia, the area of land irrigated by large-scale surface irrigation has declined since the early 1990s due largely to poorly maintained infrastructure, the report said.

Millions of small farmers throughout Asia, frustrated with poor irrigation options, have decided not to rely on the centralized government-run irrigation systems that once expanded agriculture across the continent. Instead, more farmers now own small wells and pump water whenever they choose from often shallow aquifers.

The Indian government estimates that 60 percent of the nation's farmers are using their own low-cost irrigation pumps despite the government's heavy investment in expanding surface irrigation. The rise in individual irrigation efforts may further deplete water resources, the study authors warned.

"Governments' inability to regulate this practice is giving rise to scary scenarios of groundwater over-exploitation, which could lead to regional food crises and widespread social unrest," said report co-author Tushaar Shah, an IWMI senior fellow. "Rather than condemn such a widespread practice, governments should actively support innovative initiatives."

Some solutions include public-private partnerships that improve irrigation infrastructure, the use of groundwater aquifers for storing water, and more efficient use of rainwater on farmland.

Some 280 million more hectares of land were equipped for irrigation worldwide between 2004 and 2005, the last year of available global data. The advance is one of the slowest in the past decade due to declining investment in surface irrigation infrastructure, according to a Worldwatch Institute Vital Signs update.

International funds for climate change adaptation could be tapped to improve irrigation methods. Yvo de Boer, executive secretary of the UN Framework Convention on Climate Change, estimated on Friday that adapting to the various effects of climate change would cost the world $100 billion each year.

Sweden, which currently holds the European Union presidency, has called for countries to prioritize climate change adaptation when countries meet in Copenhagen this December to reach a successor agreement to the Kyoto Protocol.

"When resources-water, arable land, other natural assets-become scarcer, we know that those without power will lose out and become even more vulnerable," said Gunilla Carlsson, the Swedish minister for international development cooperation, in the opening speech of World Water Week in Stockholm on Monday. "Their ability to adapt needs to be strengthened and supplemented."

Ben Block is a staff writer with the Worldwatch Institute. He can be reached at bblock@worldwatch.org.

This article is a product of Eye on Earth, Worldwatch Institute's online news service. For permission to reprint Eye on Earth content, please contact Juli Diamond at jdiamond@worldwatch.org.