SINGAPORE — Industrialization and urbanization across Asia have encouraged the misconception that they are the main gluttons of water. But the dominant force in Asian water consumption is agriculture.
Of the estimated 319 billion cubic meters of water used in Southeast Asia each year, 86 percent goes to agriculture, 8 percent to industry and just 6 percent to towns and cities. Agriculture’s share is even higher in South Asia (90 percent) and Central Asia (95 percent). It is bit lower (69 percent) in Japan and elsewhere in Northeast Asia. There, industrial water use accounts for 24 percent of the total and municipal use, 7 percent.
The world’s demand for water, chiefly to grow food, has been rising sharply for over a century as the population increases and material living standards improve. In 2000, half a billion people lived in countries that were chronically short of water, out of a global population of around 6 billion. By 2050, the number of people living in water-short conditions is projected to grow to 4 billion, in a population of about 9 billion.
To continue to thrive, and perhaps even to survive, as demand for water intensifies while climate change brings more erratic weather and rainfall, Asia and its farmers will have use less water to produce more food. This is a major challenge.
Irrigated agriculture and other improvements in farm productivity since the Green Revolution started in the 1960s have boosted food output and cut poverty, providing a basis for political order and economic modernization. Indeed, rural resilience has been the foundation of Asia’s growth and its impressive rise in world ranking over the past few decades.
Today, this is often forgotten. Instead, there is massive under-investment in agriculture and in making irrigation more efficient. While only 17 percent of the world’s arable land is irrigated, it produces over one-third of total food supply. A reliable supply of water allows farmers to grow two or even three crops a year.
As a recent report by the International Water Management Institute (IWMI) and the U.N. Food and Agriculture Organization (FAO) shows, Asia is the heartland of global irrigation. It contains 70 percent of the world’s 277 million hectares of irrigated land. While accounting for only 34 percent of Asian arable land, the irrigated zone produces 60 percent of the continent’s rice, wheat and other staple food grains.
But there is a dangerous downside. As practiced now, irrigated farming is very water-intensive, especially for growing rice, Asia’s main staple, in saturated paddy fields. Asia uses some 73 percent of the 2,664 cubic kilometers of water the world withdraws annually for agriculture.
There is massive wastage of water. Many of the canals, channels and other parts of the irrigation system are old, inefficient and in need of upgrading. They no longer meet farmers’ needs. So millions of smaller-area landholders have bought pumps and drilled bore holes to extract water from rivers, lakes, underground aquifers and their own storage ponds whenever they choose.
Surface water is being sucked dry in some major river basins in India, China and Indonesia. Recent surveys show that ground water tables and aquifer levels also are falling, as water is withdrawn faster than it can be replenished.
Yet the demand for food, and the water to grow it, is rising as more and more Asians migrate from the countryside to cities in search of jobs and better living standards. By 2025, 52 percent of Southeast Asians are predicted to be living in urban centers. For Northeast Asia also, the ratio is expected to be 52 percent; for South and Central Asia, 45 percent.
As people join the urban middle classes and become richer, they tend to eat less cereal. Instead, they consume more fruit, vegetables, milk and meat. For example, meat consumption in China, the world’s most populous nation, has more than doubled in the past 20 years and is expected to double again by 2030.
For Asian farmers on irrigated land, these trends have generally been good. Many are taking advantage of improved access to national and international markets. But growing more profitable niche crops (including food for animals) to satisfy urban consumers, especially those on increasingly meat-based diets, often takes much more water.
A kilogram of potatoes (not much in demand in Asia) requires just 500 liters of water to produce. The same amount of rice grown in paddies needs 1,900 liters. But a kilo of poultry absorbs 3,500 liters, while beef gulps 15,000 liters.
An estimated 5 billion people will live in Asia by 2050, 1.5 billion more than now. The continent has three broad options for meeting its food needs: Import large quantities of cereals from abroad; improve and expand rain-fed agriculture; focus on irrigated farmlands.
Many governments attach a high priority to food security, especially after the surge in grain prices in 2007 and the first half of 2008 led to export-restrictions and shortages. So there is a reluctance to rely on foreign supplies.
Still, Southeast Asia as a whole is better placed than other parts of Asia to expand irrigated land. There is a large gap between the 44 million hectares of land considered suitable for irrigation in Southeast Asia, and the currently irrigated area of 17 million hectares.
For the rest of Asia, the IWMI-FAO report suggests that the main thrust of future reform and investment in agriculture should be directed toward improving irrigation systems, with help from farmers and the private sector.
Michael Richardson is a visiting senior research fellow at the Institute of Southeast Asian Studies.