World Water Week: lower consumption not increase supply, Unesco expert says

Prof David Hannah says daily water use in the UAE averages 550 litres per person, one of the highest in the world

Dubai company Terraplus uses underground technology to water palm trees. It claims this could save up to a trillion litres of water a year in the UAE if widely adopted by date farmers. All photos by Antonie Robertson / The National

Khalil Ur Rahman, who works closely with the Terraplus project, shows water seeping through the company's unique underground watering system. It allows water to reach the roots, which often clog up traditional underground pipe systems

Traditional topsoil watering 'bubblers', like the one pictured, have an evaporation rate of about 30 per cent

Khalil Ur Rahman checks a water flow meter on a traditional watering bubbler used for irrigation in the UAE

The Terraplus system may save water in the UAE if date farmers adopt the technology

The Dubai firm claim its system could save the country up to a trillion litres a year

Terraplus co-founders Patrick Stevens and Nicolas Bruylants with an above-ground display of the system

At a time of population growth and increasing concern about climate change, countries such as the UAE should look at ways to limit demand for water, a leading expert has said.

While discussions concerning water often centre on how to maintain or increase supply, Prof David Hannah, a Unesco chairman in water science at the University of Birmingham in the UK, said that was just part of the equation.

Speaking to The National ahead of taking part in a World Majlis to be held at Expo 2020 Dubai on World Water Day on Tuesday, March 22, he said progress could be made by reducing water demand from agriculture and changes to individual behaviour.

“We really need to consider the demand side,” he said. “That’s particularly important given the population has grown.”

He noted daily water use in the UAE averages 550 litres per person, “one of the highest” figures globally.

Greater efforts to re-use water and behavioural change could help to limit demand, Prof Hannah added, as could regulation to encourage water conservation and the need to consider the cost of water.

In the region as a whole, Prof Hannah noted agriculture consumed large quantities of water, accounting for as much as 70 per cent of demand, compared to 20 per cent for households and 10 per cent for industry.

“A large proportion is used for agriculture,” he said. “How subsidies are provided for water-intensive crops has to be thought through.”

In terms of their own impact, people should consider not just their personal use, but also how their food and other goods, such as clothing, impacts on demand for water as part of an individual’s “global water footprint”, Prof Hannah said.

Demand for water goes up as population surges

Globally, freshwater use has grown several-fold over the past century as the world’s population has increased.

According to OurWorldinData, using figures from the Global International Geosphere-Biosphere Programme (IGBP), total global freshwater withdrawal – water taken from ground or surface resources – was 671.31 million cubic metres in 1901.

In 2014, the last year for which the IGBP compiled figures, the total was 3.99 trillion cubic metres.

While water use in the UAE is several times that in many other nations, efforts have been made to limit consumption for a number of years.

For example, in 2010 the Environment Agency Abu Dhabi launched a “Watersavers” campaign to install water-saving devices in the emirate’s domestic, government, educational, religious and industrial buildings.

The UAE has also become an important centre for hydroponic agriculture, in which plants are grown in nutrient solutions instead of soil and water use is a fraction of that of conventional agriculture.

Amid high demand for water, the effects of climate change add another layer of uncertainty because, Prof Hannah said, it was clear temperatures in the region would increase, but forecasts for precipitation range from a 20 per cent decrease to a 10 per cent increase.

Putting people in the water cycle

At Expo 2020 Dubai, Prof Hannah will be giving a speech at Terra – The Sustainability Pavilion on the Price of Water.

As part of his role holding a Unesco chair in water science, he is keen to improve education about the water cycle, the term for how water moves and is stored in the different atmosphere, land and ocean compartments of the cycle.

He is also keen that the influence of people on the water cycle is recognised.

An international research project Prof Hannah was involved with looked at 450 diagrams of the water cycle in a range of media, including textbooks and scientific articles.

It was found that 85 per cent of diagrams did not depict people in the water cycle, despite the significant role humans have, while just two per cent of diagrams featured climate change and two per cent pollution.

“That made us feel the water cycle is misrepresented, because people do have an effect on the water cycle,” he said.

“There’s a lack of awareness of how people relate to water. That gives us a false sense of security about current and future availability of water.”

The effects people are having on water-related systems are significant but often not widely appreciated, he indicated, because wetlands are disappearing three times as fast as forests but do not get as much attention.

As well as water quantity, he said water quality was a critical issue, with an estimated 1.8 million people dying each year because of polluted water.

Hydroponics farming - in pictures