Water Wars

The Legacy We Will Leave to Our Grandchildren: Water Scarcity

Water is a substance that is the source of life. For this reason, the existence of liquid water is being investigated in the search for life outside the Earth.

Water is a substance that is the source of life. For example, water is needed in all functions in the human body (such as digestion, circulation, respiration, excretion, reproduction). For this reason, the existence of liquid water is being investigated in the search for life outside the Earth. When viewed from space, our planet appears as a blue sphere. This is because approximately 71% of its surface is covered with water. Liquid water is the most important substance that separates the Earth from other planets in the Solar system. Geological evidence shows that liquid water has existed on Earth for 3.8 billion years.

There are often large differences between the melting and boiling temperatures of a substance. However, water can exist as solid, liquid and gas within a relatively narrow temperature range. So, is water, the source of life, as abundant as we think on our planet?


There is 1,386,000,000 km3 of water on Earth, approximately equal to the volume of a sphere with a diameter of 1,385 kilometers. 96.5% of the water on Earth is in the oceans, and the rest is in the form of water vapor in the atmosphere, oceans, lakes, rivers and glaciers. However, fresh water is needed for the life of living things. Only 2.5% (10,633,450 km3) of the water in the world consists of fresh water. Water consumption on a global scale is increasing day by day. In addition, changes in climate due to global warming, increased frequency of extreme weather events and pollution of clean water resources lead to the gradual depletion of clean fresh water resources. One-third of the world's countries have no or very limited access to water. 18% of the world's population cannot access clean water.

The decrease in water resources leads to negative effects such as migration and epidemics.This is because approximately 71% of the Earth's surface is covered with water. One unique characteristic of water is that it can exist as a solid, liquid, or gas within a narrow range of temperatures. With water being the source of life, it's important to consider its abundance on our planet. 96.5% of the water on Earth is found in the oceans, while the rest exists as water vapor in the atmosphere, as well as in lakes, rivers, and glaciers. However, global water consumption is steadily increasing, leading to a decline in water resources. This decline, in turn, has negative consequences such as migration and outbreaks of diseases.

The supply of clean fresh water in the world is limited. The reason why this resource is not depleted despite its constant use is that water is recycled on a global scale through a process called the water cycle. Every year, 577,000 km3 of water (more than the water mass in the Black Sea) is circulated in this cycle.

Role of Water Cycle:The supply of clean fresh water in the world is limited. The reason why this resource is not depleted despite its constant use is that water is recycled on a global scale through a process called the water cycle. Every year, 577,000 km3 of water (more than the water mass in the Black Sea) is circulated in this cycle.




502,800 km3 of this water evaporates from the ocean surface, and 74,200 km3 evaporates from the land. As the evaporated water moves upward in the atmosphere, it cools and condenses into precipitation. Thus, the same amount of water that evaporates reaches the oceans (458,000 km3) and the land (119,000 km3) as precipitation.


The difference between the amount of water moving away from the land surface by evaporation and returning to the land by condensation is 44,800 km3 per year. This figure is equal to the amount of water carried from the land to the oceans by rivers (42,700 km3) and groundwater (2100 km3). This is the source of fresh water necessary to sustain people's vital needs and economic activities. However, fresh water is not evenly distributed around the world. While some regions are richer in terms of water resources, in some regions water resources are quite limited. Approximately 32% of our annual 42,700 km3 fresh water resources are in Asia, 28% in South America, 7% in Europe and 6% in Australia. When the amount of fresh water resources in a region is less than the amount of water needed, it is called water stress. While water stress is high around the world, especially in Africa, water stress is low in North America.

What is Türkiye's situation regarding water resources?

Our country's surface and underground fresh water potential is 112 km3 per year. Today, we can only benefit from 27.5 km3 of our 95 km3 surface water potential. Approximately 76% of these resources are used for irrigation, 14% as drinking water and 10% in industry.

Countries are classified according to the amount of usable fresh water per person per year. If this value is less than 1,000 m3, it is considered water scarcity, if it is between 1,000-1,700 m3, it is considered water stress, and if it is more than 1,700 m3, it is considered water richness. The amount of usable fresh water per capita in our country is 1,555 m3. In other words, Türkiye is among the countries included in the water stress class. According to data from the United Nations Food and Agriculture Organization (FAO), the rate of countries experiencing water stress may reach 34% and the rate of countries experiencing water scarcity may reach 15% in 2025. In addition, 40% of the world population, which is expected to reach 9.4 billion in 2050, may suffer from water shortage.

Therefore, efficient use of water resources in our country and around the world becomes more important every day. For example, shortening the bath time, washing fruits and vegetables by keeping them in a container filled with water instead of washing them under running water, and choosing water-saving appliances such as dishwashers and washing machines are just a few of the precautions we can take. Because in addition to the water we consume directly, we also indirectly waste fresh water resources. For example, the amount of water used to produce a t-shirt we wear (that is, from the production of cotton in the field to its transformation into yarn and t-shirts in the factory, from its transportation to the store where it will be sold until it reaches us) is approximately 2,500 liters. This concept, called water footprint, shows the amount of water consumed directly and indirectly by an individual.

As the world population increases day by day, fresh water resources become more polluted. Therefore, it is very important to protect clean fresh water resources not only for ourselves, but also for future generations and other living things. In order to raise awareness on this issue, March 22 is celebrated as World Water Day every year by the United Nations. We can reduce our own water footprint by paying attention to using water in the most efficient way.

Resources:

• Hiklomanov, I. A., “Appraisal and Assessment of World Water Resources”, Water International, Volume 25, Issue 1, p. 11-32, 2000.
• Marco, J. L. et al., “Monitoring water resources and water use from earth observation in the belt and road countries.”, Bulletin of Chinese Academy of Sciences, Volume 32, p. 62-73, 2017.
• Vanham, D. ve Leip, A., “Sustainable food system policies need to address environmental pressure sandimpacts: The example of water use and water stress.”, Science of The Total Environment, Cilt 730, Makale no: 139151, 2020.
• FAO, Crops and Drops: Making the Best Use o f Water for Agriculture, Rome, 2002.
• https://www.earthobservatory.nasa.gov/features/Water
• https://www.caee.utexas.edu/prof/mckinney/ce385d/Papers/Shiklomanov.pdf
• https://dergipark.org.tr/en/download/article-file/405859