Fresh water accounts for only 2.5% of the world’s reserves: it can become one of the most valuable resources in the world, regional or even global wars will break out around. We will tell you how to prevent this.
Why can there be a shortage of fresh water?
Drinking water scarcity is associated with the effects of climate change, human activities that reduce water resources due to pollution of freshwater ecosystems, and the effects of urbanization and land-use changes.
According to statistics, almost 1/5 of the world’s population lives in areas where there is a serious shortage of clean drinking water. In addition, 1/4 of the population lives in developing countries, which are experiencing water shortages due to the lack of infrastructure necessary for its withdrawal from aquifers and rivers.
One of the main ones is the problem of fresh water pollution, which significantly reduces the available reserves. This pollution is facilitated by industrial emissions and runoff, fertilizer runoff from the fields, and the penetration of salt water in coastal zones into aquifers due to pumping of groundwater.
How fresh water is polluted
Pollutants enter fresh water in a variety of ways: through accidents, deliberate waste disposal, spills and leaks.
The largest potential source of pollution is farming, which occupies almost 80% of the land in England and Wales. Some of the untreated animal manure that covers the soil enters fresh water sources.
In addition, farmers in England and Wales apply 2.5 million tons of nitrogen, phosphorus and potassium to the soil annually, and some of this fertilizer ends up in fresh water. Some of them are persistent organic compounds that enter the food chain and cause environmental problems. The UK is now phasing out the production of organochlorine compounds produced in large quantities in the 1950s.
An increasing threat to freshwater bodies is posed by wastewater discharged by fish farms, due to their widespread use of pharmaceuticals to combat fish diseases.
Rapid pollution of groundwater around cities. The source is the increasing number of contaminated wells due to improper operation.
Forestry and open drainage are sources of large quantities of substances that enter freshwater, primarily iron, aluminum and cadmium. With the growth of trees, the acidity of the forest soil increases, and heavy rains form very acidic runoffs that are detrimental to wildlife.
Atmospheric pollution of fresh water is especially harmful. There are two types of such pollutants: coarsely dispersed (ash, soot, dust and liquid droplets) and gases (sulfur dioxide and nitrogen dioxide). All of them are products of industrial or agricultural activity. When these gases combine with water in a raindrop, concentrated acids are formed – sulfuric and nitric.
Global pollution of water bodies
Ecological disasters. All serious cases of ocean pollution are related to oil. As a result of the widespread practice of washing tanker holds, between 8 and 20 million barrels of oil are deliberately dumped into the ocean every year. In sediments of a temperate climate, the consequences of oil spills can be traced for more than 9 months. In arctic conditions, oil lasts much longer.
Wastewater. In small quantities, they enrich water and promote the growth of plants and fish, and in large quantities, they destroy ecosystems. In the two largest wastewater disposal sites in the world – Los Angeles (USA) and Marseille (France) – specialists have been treating polluted water for more than two decades. The satellite images clearly show the spreading of the effluent discharged by the exhaust manifolds. Underwater surveys indicate the mass death of marine organisms.
Metals and chemicals. Hazardous chemicals that can disrupt the ecological balance include such heavy metals as cadmium, nickel, arsenic, copper, lead, zinc and chromium. It is estimated that up to 50,000 tons of these metals are dumped annually into the North Sea alone. Of even greater concern are the pesticides aldrin, dieldrin and endrin that accumulate in animal tissues. The long-term consequences of the use of such chemicals are still unknown.
Impact on ecosystems. All oceans suffer from pollution, but coastal waters are more polluted than open oceans due to many more sources of pollution, from coastal industrial installations to heavy sea traffic. Around Europe and off the eastern shores of North America on shallow continental shelves, cages are being set up to breed oysters, mussels and fish vulnerable to toxic bacteria, algae and pollutants.
Blooming water. The first-order consumers cannot cope with the explosive growth of phytoplankton biomass, as a result of which most of it is not used in food chains and simply dies off, sinking to the bottom. By decomposing the organic matter of dead phytoplankton, benthic bacteria often use all the oxygen dissolved in the water, which can lead to the formation of a hypoxia zone (with an insufficient oxygen content for aerobic organisms). Such zones lead to a decrease in the biodiversity and biomass of aerobic forms of benthos.
Contamination from plastic waste. Accumulations of plastic waste form special garbage spots in the oceans under the influence of currents. At the moment, five large accumulations of garbage patches are known – two each in the Pacific and Atlantic oceans, and one in the Indian Ocean. These waste cycles are mainly made up of plastic waste from discharges from the densely populated coastal areas of the continents.
How the world’s water resources are distributed
About a third of all fresh water reserves are concentrated in South America, a fourth of it is in Asia, and the post-Soviet countries account for a little more than 20%. And only about 2% is distributed to the Middle East and North Africa.
The largest consumers of fresh water are considered to be India, China, USA, Pakistan, Japan, Thailand, Indonesia, Bangladesh, Mexico and Russia. At the same time, a particularly acute shortage of drinking water is observed in China, India and throughout Africa.
In addition to the lack of fresh water, there is another urgent problem – its quality. Its deterioration directly depends on the increased level of environmental pollution. In most cases, this is due to human activities and overpopulation.
