Global water supply issues are undoubtedly a key concern in the science and engineering community’s ongoing discussion about climate change. The Columbia Water Center hosted Marshall English last week to talk about the role crop irrigation plays in water resource planning and problem solving. A professor in Oregon State University’s Biological and Ecological Engineering Department, English’s study of irrigation management issues — particularly in arid and semi-arid climates — spans more than three decades.
A video of English’s lecture can be viewed here:
Although he predicts a period of enduring water crisis in the near future, English suggested that better irrigation management can ease strain on the global water supply. The U.S. Geological Survey reports that 60 percent of the world’s water — approximately 638 million acre-feet per day in the U.S. alone — goes to crop irrigation.
Irrigation management is the weak link in the future,” he said. “You can have a good system in the field, but it’s nothing if it’s not properly managed.”
Even with more efficient irrigation technology, the value of increasingly scarce water makes good management more of a challenge. English recalled that in 2009, for example, a farmer in California’s Central Valley sold 14,000 acre-feet of water rights to another farmer near San Bernardino — on the other side of a mountain range reaching elevations of 7-10,000 feet — for $77 million.
“That raises the question, right off the bat, is water becoming more valuable than food?”
But English answered his own question with a series of studies indicating that food production can still compete with the high cost of water — if properly managed, of course.
English posited that food security issues not seen since the middle of the last century have begun to surface in recent years as the world’s population, sea levels, and climate increase. The Green Revolution of the 1950s, 60s and 70s greatly increased grain production worldwide, but today, in an era of energy uncertainty, massive volumes of petro-fuels will not likely provide a solution, he said.
Qatar, for example, recently unveiled a scheme to increase seawater desalination and increase domestic agricultural production by 60 to 70 percent by 2023. Located on a parched peninsula jutting into the Persian Gulf, Qatar currently imports 90 percent of its food from abroad. But desalination is energy intensive and produces high salinity runoff.
To give some perspective, the Pacific Institute estimates that for a desal plant the size of the one in Perth, Australia, it takes about 1.3 megawatts of electricity to produce an acre-foot of water. English said that briny discharge from an escalating number of desalination plants in Gulf states over the past ten years has led to a ten percent increase in the salinity of Persian Gulf waters.
- graywater recycling and more innovative irrigation scheduling. Based upon peaks in irrigation use, he said that farmers may have to take low value crops out of production and deficit irrigate others, but that the long term benefits of scheduling would make the practice worthwhile English recommended a number of measures to improve irrigation efficiency, including
Irrigation scheduling appears pragmatic, but many farmers haven’t yet adopted it. English cited three main reasons: Copious amounts of time and energy set up the program; the potential benefits may not be apparent to farmers who don’t understand how the system works; and perhaps most importantly, uncertainty of program funding — farmers don’t want to invest in a system that will disappear after a few years. By better educating farmers, English said, many of these concerns can be addressed.
The Columbia Water Center will host other seminars for the Spring 2011 semester:
‘Investigating Pathogen Transport in Bangladesh Aquifer Soils’, Patricia Culligan, Professor of Civil Engineering, School of Engineering and Applied Science, Columbia University
March 4, 12:15 to 1:15, Seeley W. Mudd Building, Room 924
‘Water Quality Violations and Avoidance Behavior – Evidence from Bottled Water
Consumption, Wolfram Schlenker, Department of Economics, School of International and Public Affairs, Columbia University
March 25, 12:15 to 1:15, Seeley W. Mudd Building, Room 924
‘Innovations in Delivering Safe Water to the Bottom of the Pyramid (BOP)’, Marc Manara, Water Portfolio Manager, Acumen Fund
April 1, 12:15 – 1:15, Seeley W. Mudd Building, Room 924
‘Water for a Crowded World: Lessons from the Northeast Corridor’, Charlie Vorosmarty,
Professor of Civil Engineering and Director of the City University of New York’s Environmental Crossroads Initiative, CCNY
April 8, 12:15 – 1:15, Seeley W. Mudd Building, Room 924
‘Distributive Impacts of Dams and Governmental Responses at County-level in China’
Xiaojia Bao, PhD student in Sustainable Development, School of International and Public Affairs, Columbia University
April 22, 12:15 – 1:15, Seeley W. Mudd Building, Room 924
‘Title TBA’, Ray Farinato, Cytec
Co-Hosted with the Department of Earth and Environmental Engineering
April 29, 3:00 – 4:00 pm, Reception 4:00 – 5:00 pm, Seeley W. Mudd Building, Room 833