Bytes and bottlenecks – can data deliver?
Leaps forward in data processing power and access to information are helping make irrigation more efficient and sustainable. Today, World Development Information Day, we take a look at some of the possibilities and some of the challenges.
Irrigation has long been the backbone of global food security, but it has also made agriculture the world’s biggest consumer of freshwater. While some irrigation systems work well, others don’t, and some are plain misguided: the much-diminished Aral Sea in Uzbekistan is a stark reminder of the effects of irrigation at its worst.
Fortunately, there is plenty of room for improvement, and remote sensing – the use of satellite images combined with a lot of number crunching – is playing an increasing role in identifying the problems and possible solutions. It’s a relatively cheap method compared to monitoring on the ground and, a lot of the time, more accurate.
Global Information Systems experts at the International Water Management Institute (IWMI) have been using satellite data to monitor all kinds of water issues, from water productivity in India – essentially the amount of crop-per-drop – to mapping the spread of irrigation wells in northern Sri Lanka and the implications this may have on the quality and quantity of groundwater reserves.
They’ve also been using satellite data to monitor evapotranspiration – the rate at which water is lost as vapor from plants and soil – on a site-specific, plot-by-plot basis. In pilot projects in Ethiopia, Egypt and Sudan, irrigation managers receive this information via text message, in order to help them decide whether to open the sluice gates in some places or turn off the pumps in others. That’s smart.
The recently developed IWMI Water Data Portal – an online tool – not only provides free access to water-related data but enables users to monitor everything from flood-risk mapping to global drought patterns. It’s already available as part of the IWMI Data smartphone app. As the price of smartphones tumbles, eventually it could be used by farmers to help them make decisions about how they manage their water.
However, while new technologies like these can help generate and disseminate new information, it doesn’t necessarily follow that water will then be used more efficiently. That’s where it becomes a, well, slippery subject.
“We often hear that if you can’t measure something you can’t manage it,” says Salman Siddiqui of IWMI, one of the architects of the Water Data Portal. “But better information is only part of the issue. How you then act as, for example, a policymaker will depend to a great extent on what your priorities are, and the trade-offs between them.”
For example, if your top priority is to protect the long-term health of the surrounding ecosystem, you might want to reduce irrigation. Think of the Aral Sea. But that could put a dent in crop yields, which in turn could affect your ability to produce enough food, feed, fiber or fuel, and reduce poverty.
On top of that, even when you know water is being used poorly, it might still be difficult to change behavior. In parts of India, water is so heavily subsidized that hundreds of thousands of farmers have little incentive to use it more efficiently. Politicians tinkering with systems like that are unlikely to win many votes.
“Remote sensing will not solve these kinds of problems,” continues Siddiqui. “But having the data can make a huge difference, and at least it means you have better information on which to set your priorities and take your decisions.”