Developing countries are failing to account for where water is going, how it is being used and how much of it remains, according to a major report by the UN Food and Agriculture Organization (FAO).
The report, 'Climate change, water and food security', published earlier this month (9 June), aims to sum up current scientific understanding of the impacts of climate change on agriculture and agricultural water management, and to highlight knowledge gaps.
"Water accounting in most developing countries is very limited, and allocation procedures are non-existent, ad hoc or poorly developed," the report said.
"Acquiring good water accounting practices (hydrological analysis of water resource availability and actual use) and developing robust and flexible water allocation systems will be a first priority [for adaptation]."
Such data would help more accurate forecasting of droughts and floods. Although forecasting technologies are commercially available in some developed countries, their quality, as well as their communication and understanding among farmers, must improve if farmers are to better adapt to climate change and reap the benefits, the report says.
For example, more research is needed on how water vapour and precipitation might change in the coming decades to help computer models predict future scenarios more accurately, said Jacob Burke, senior water policy officer for the FAO and co-author of the report.
"In the meantime [farmers] must keep track of the climate and learn to monitor the environment rather than stick rigidly to old routines," he said. "Farmers with no access to formal research have to be given the message that tried and tested farming practices and routines might not work in future."
Vijay Jagannathan, infrastructure sector manager for the East Asia and Pacific region of the World Bank, welcomed the report, saying it focused thinking on water, land and food — which are all central to discussions on climate change.
"What we need now is a set of metrics — similar to global financial markets — with which to measure water use and which can guide decision making," he said.
Jagannathan said there had been a "huge amount of freedom" with water use historically, with 70 to 80 per cent of it used for irrigation.
"There is a lot of inefficiency in the existing system," he said. "The report articulates the importance of finding a win-win solution so everyone can benefit from a limited resource."
Link to full report [7.44MB]