Water Scarcity? Four original solutions | Knowledge and the environment | DW

The world is thirsty and consumes more drinking water than is available in many places. More frequent and prolonged droughts due to man-made climate change and poor water management are exacerbating the problem.

According to a recent study by the United Nations University Institute for Water, Environment and Health, half of the world’s countries will experience water scarcity by 2050. These include countries in the Sahel region of Africa, and regions in the Middle East and Asia. So scientists came up with some original ideas on how to solve the problem.

Moving icebergs from the Arctic to Africa?

The Arctic glacier consists of 27 million cubic kilometers of water, of which 100,000 icebergs break into the sea and melt each year. The huge blocks are a huge untapped source of fresh water. Some scholars believe you can benefit from this. For example in Cape Town, South Africa. The city almost ran out of water in 2017.

“Some people have brought up the idea of ​​using icebergs from the Northern Hemisphere to combat the water shortage in Cape Town,” says Mansour Qader, a researcher at the United Nations University in Hamilton Canada and editor of the book. Unconventional water sources.

At least for moving smaller icebergs up to about a hundred meters wide, the technology is already available. Oil and gas companies pull such pieces of ice a few kilometers away with smaller ships when they get dangerously close to oil rigs. But no one has ever moved a real giant iceberg across hundreds of kilometers.

On a collision course with Borough Island, ships drag an iceberg

In practice, the amazing idea actually worked: in 2011, a huge iceberg was successfully transported from Newfoundland across the Atlantic Ocean in scientific computer simulations. But “such simulations are based on certain assumptions that are often very vague,” Kader says. He has doubts about whether it is physically possible to pull a huge iceberg without it disintegrating. Because for such a project to be feasible, he estimated that the transported iceberg would have to be 1 kilometer long, 500 meters wide, 250 meters deep, and weighing 125 million tons, for comparison: the legendary Titanic weighed about 50,000 tons.

Such a gigantic iceberg can meet about a fifth of Cape Town’s water needs for a year.

However, there are still many unanswered questions: for example, to what extent meter-high waves across hundreds or thousands of kilometers can impede transportation, how much ice will melt on the road and what consequences for Ecosystems in the sea. So moving icebergs for fresh water supplies isn’t a priority for Quadir right now. However, many other options can already be used today.

Cloud Rain – Make your own rain

Malaysia |  rain clouds

Malaysian Air Force wants to prevent forest fires by seeding clouds

What if you let the rain fall where you want it? It sounds crazy, but it’s possible. This method is called cloud seeding.

One supposed magical remedy: silver iodide. The chemical is released in rain clouds with the help of missiles or aircraft. Silver iodide binds moisture in clouds to droplets that fall to the ground as rain.

A program is already underway in China that will use cloud seeding to protect agriculture during droughts and combat wildfires and bushfires in an area 1.5 times the size of India. In Russia, the method is used regularly until the sun rises on public holidays and military parades. So that the clouds do not spoil the show, they make it rain in advance. The chemical’s environmental impact has been rated very low in long-term studies. According to another study, ecosystems could still be affected if they were used worldwide and greatly expanded.

“Even small amounts of silver iodide are toxic to marine organisms,” warns Thara Prabhakaran, a cloud physicist at the Indian Institute of Tropical Meteorology. And although the chemicals are very diluted before they reach the ground, there are very few risks related to that information far,” Prabhakaran says.

And: making precipitation in areas where it almost doesn’t rain now wouldn’t be possible that way either. It needs special clouds and accurate weather forecasts, as well as technical equipment that is by no means available everywhere. The scientist explains that in very hot regions, raindrops can also evaporate before they reach the ground. Cloud seeding is not the only solution for the whole world. But for certain regions, making artificial rain could be an opportunity if the method is viable and scientifically reasonable there.

Fog Harvest: Tiny Drops of Air

Extended network for collecting water on the mountain

Fog can also be harvested in Spain, as in Tenerife

However, it does not have to be high-tech to take advantage of atmospheric moisture. Fog ‘harvesting’ is an age-old tradition that can be a reliable source of fresh water, especially for communities in arid mountainous regions.

At night there it cools significantly, the air humidity rises and there is a regular fog. Net-like nets of about 1 square meter or larger are placed perpendicular to the wind direction. When the wind blows the mist through the nets, moisture gets trapped in it. Drops form and flow into a tank that collects water. The method is already being used successfully, particularly in rural areas of Chile, Morocco and South Africa. In projects in Eritrea, villages are already collecting a total of 12,000 liters of water per day in this way. The water there is used as drinking water. “It is not only about water, but also about social and economic aspects,” Kader says.

“Women who used to have to walk miles to get to the nearest water source can now do other work, and the children can go to school.” The 40-meter system costs about $1,500 (1,400 euros) and produces about 200 liters of water per day. At least 70 regions on all continents, it will be clear that the Nebelernten is an alternative source of drinking water.

Good for tanks and cisterns: collect rainwater

Storing rainwater in small rain barrels or large ponds has been a method people have used for a very long time. The oldest known aquifers are more than 5,000 years old. However, the potential of rainwater worldwide is far from fully exploited. Especially in the dry regions of the world such as the Middle East, the Sahel region or Asia, more than 90 percent of rainwater evaporates without being used or simply being carried out.

Peru |  Sunrise in the Inca city Machu Picchu

Even the Incas collected water by building terraces. But there is an easier way

The possibilities are varied. Anyone can collect sedimentation by installing gutters and pipes in a water collection tank and using it for farming or filtering as drinking water. In cities where water is scarce, rainwater harvesting from rooftops, for example, not only secures drinking water supply, but also reduces sewage overflow in heavy rainfall.

Specially constructed trenches and dams can greatly enhance moisture storage in the soil. When it rains, the water is directed where you need it. There they can slowly seep, long-term watering of plants and at the same time protecting the soil from erosion.

The authors of the 2020 study estimated that continuous harvesting of rainwater could increase agricultural production by 60 to 100 percent in Uganda, Burundi, Tanzania, and India.

Leave a Comment