Water scarcity is one of the top five global risks to human wellbeing. The situation is dire in arid areas. Traditional sources such as snowfall, precipitation, river runoff and easily accessible groundwater are affected by climate change, and supply shrinks as demand increases.
In these countries, water is a critical challenge for sustainable development and a potential cause of social unrest and conflict. Water scarcity also affects traditional seasonal human migration routes and, along with other factors of water insecurity, could alter migration patterns.
Arid countries need a fundamental change in planning and management. We are looking at how this can be achieved through the creative use of unconventional water resources.
From the ocean floor to the upper atmosphere, we have a multitude of water resources that can be tapped. However, a variety of technological interventions and innovations are required to make the most of it.
Catch the fog. Aqualonis, author provided
Catch the fog
Water embedded in fog is increasingly viewed as a source of drinking water in arid areas where fog is intense and regular. Fog can be collected using a vertical mesh that intercepts the stream of droplets. This water then flows into a water collection, storage and distribution system.
Various types of screen materials can be used in mist collectors, e.g. B. aluminum, plastic, plexiglass and alloys. The success of such a system depends on the geography and topography, which must be conducive to optimal interception of fog. However, this could work in arid mountain and coastal regions.
With the active engagement of local communities and technical support from local institutions, fog water use is a low maintenance option and an environmentally friendly technology for providing drinking water. Fog water collection projects have been carried out in various parts of the world, including Chile, Eritrea, Israel and Oman.
Under the right conditions, rain reinforcement from cloud seeds can increase the volume of water from the air. With this technology, small particles are distributed in clouds or in their surroundings. These particles serve as the starting point for raindrops or ice crystals and promote their formation. This in turn increases the chance of rain or snow.
The application of cloud seeding technology in different countries has shown that precipitation can increase by up to 20% of the annual norm depending on the available cloud resources and types, the cloud water content and the base temperature. Since only up to 10% of the total cloud water content is released into the ground as precipitation, there is great potential for rain improvement technologies to increase precipitation in arid areas.
Since there is little rainfall in dry areas, rainwater harvesting in micro-catchment areas can help catch rainwater on the ground where it would otherwise evaporate.
There are two main types of micro-basin rainwater harvesting systems. One of these is the use of water via roof systems, in which the runoff is collected and stored in tanks or similar devices. This water is used domestically or for irrigation of farm animals.
The second is water use for agriculture, in which the rainwater that flows from a catchment area is collected in a small reservoir or in the root zone of a cultivated area. The catchment area can be natural or treated with a material that prevents the soil from absorbing water, especially in areas with sandy soils. Due to the intermittent nature of the runoff, it is necessary to store the maximum amount of rainwater during the rainy season so that it can be used later.
Dry areas have to absorb all the rain they get. Theib Oweis ICARDA, author provided
Desalinate sea water
The desalination process removes salt from seawater or brackish groundwater to make it potable. This enables us to collect water that goes beyond what is available from the water cycle and to guarantee a constant supply of high quality water, regardless of the climate.
Seawater desalination has increased faster due to advances in membrane technology and materials science. These advances are expected to result in a significant decrease in production costs by 2030.
It is expected that more places will depend on desalinated water due to falling costs and rising costs of conventional water resources. While desalination currently accounts for around 10% of the municipal water supply in urban coastal centers worldwide, it is expected to reach 25% by 2030.
Towing an iceberg from one of the polar ice caps to a country with water scarcity doesn’t seem like a practical solution to water scarcity, but scientists, scientists, and politicians are considering harvesting icebergs as a potential source of freshwater.
The United Arab Emirates and South Africa are investigating iceberg towing. Nicholas Sloane Southern Ice Forum, author provided
Moving an iceberg across the ocean is technically possible based on a theoretical four-part process. It would require finding a suitable source and supply, calculating the required towing power requirement, accurately predicting melting during transport and assessing the economic feasibility of the entire project. Countries like the United Arab Emirates and South Africa are considering iceberg towing as an option to fill gaps in water demand and supply.
Water and climate change are linked, so climate change increases the likelihood of extreme droughts in arid areas. Harnessing the potential of unconventional water resources can help increase the resilience of arid communities to climate change while diversifying water supply resources.
We need to identify and promote functional systems of unconventional water resources that are environmentally friendly and economical and support the achievement of water-related sustainable development in the 2030 Agenda for Sustainable Development and beyond.
This article by Manzoor Qadir, Deputy Director of the United Nations University Institute of Water, Environment and Health, and Vladimir Smakhtin, Director of the United Nations University Institute of Water, Environment and Health, was published by The Conversation under a Creative Commons License republished. Read the original article.