Transformation of a lake into a desert. Environmental Effects and Social Consequences.

ufv (58)in #ecology • 7 years ago

Hello dear friends Steemians!

It is known that man has always intervened positively or negatively in the environment, and that this intervention alters the normal functioning of ecosystems. In the eagerness to secure food, energy, water and space, man modifies his natural environment affecting his quality.

I recently found a publication about an event that has been cataloged as one of the largest environmental catastrophe in the world. When natural resources are exploited, it is considered that these resources will be the same despite the use and abuse we make of them.

The Aral Sea, is a saltwater lake located in Central Asia between the cities of Kazakhstan and Uzbekistan, has no access to the sea (Endorheic lake) and is fed by the currents of the rivers Amu Daria and Sir Daria. Until the 1960s it was considered as the fourth largest lake in the world, with abundant biological diversity.

Location of the Aral Sea

In the past, the deltas of the Amu Daria and Sir Daria rivers were fertile places where many species of animals and plants lived at ease. The sea was home to fish and seaweed, as well as other creatures. Common fish were the sturgeon, the carp, the barral of the Aral (Barbus brachycephalus) and the rutile. It is estimated that the region housed around 100 species of fish, 200 of mammals and up to 500 of birds.
GeoEnciclopedia

At present, the Aral Sea has disappeared in its three quarters becoming the youngest desert that is known: Aralkum. It is estimated that in the last 50 years it has reduced its water volume by 90 percent.

The following video shows a sequence of satellite photos from NASA that summarize this reduction.

Shocking timelapse of the shrinking Aral Sea (Youtube)

How did this happen?

In the areas surrounding the Aral Sea are population settlements that for a long time lived from fishing and commercial activities related to the lake. The water quota contributed by each river allowed the volume of water in the lake to remain stable despite the evaporation produced by the high temperatures in the area.

A large-scale cotton production project developed by the Soviet Union was the main cause of the drying up of this great lake. The courses of the Amu Daria and Sir Daria rivers was diverted through the excavation of numerous channels to be used in the irrigation of cotton crops, which caused the reduction of their flow in the course of several decades.

Port on the shores of the Aral sea before desiccation

Vestiges of the Port of the Aral sea

By decreasing the amount of water that fed the lake, concentrations of salts and minerals increased dramatically making life impossible in its waters.

The diminished water generated less condensation and consequently less rainfall. The layer of salt that formed on the seabed sterilized the soil and was also spread in the air by the effect of wind, impacting the vegetation and crops in its surroundings. The vegetation began to be scarce which led to a reduction in the production of water vapor that is made through the process of transpiration of it. To this we must add the dry climate typical of the Central Asian region.

Finally, after several decades, the landscape became a desert of sand and salt, completely destroying the fauna and floral habitat of the place and affecting the surrounding communities by losing their source of work and drinking water.

Seabed of the Aral sea

Old boats where there used to be a lake

Climatic and environmental alterations caused by desiccation of the lake

The microclimate of the area underwent modifications due to the withdrawal of the waters. According to the opinion of the scientists of the Aral Meteorological Station:

The temperatures of the seasons were accentuated, producing very hot summers and very cold winters.
The winds became stronger. Every three days there are storms with winds that exceed 55 km/h, which displace tons of saline sand to the houses and streets of nearby towns, and that generate soil erosion and the formation of Dunes.
To this is added the fact that the air and aquifers (Phreatic zone) were contaminated by the use of fertilizers and pesticides in the cotton crops.

A natural catastrophe caused by the hand of man

Social consequences

The social impact caused by the disappearance of the Aral sea is mainly economic and health. The City of Akespe, one of the most affected, is located southwest of Kazakhstan, its main economic activity was fishing. and due to the desiccation of the lake its streets were desolated as their only source of work disappeared. Only a small group of families continued to live in their homes and were dedicated to the breeding of Camels and to a lesser extent to fishing in the distant waters every day more removed from the ancient shores.

Air pollution with dust, salt and pesticide residues from cotton crops led to the proliferation of different diseases and an increase in the mortality rate, especially infant mortality. Below I share more accurate information about diseases that affect the inhabitants of the area.

The region registers the highest infant mortality rate of all the former USSR. Chronic bronchitis has increased by 3000% and arthritis by 6000%. In the Uzbek region of Karakalpakstan women suffer from a pandemic of anemia and 97% have hemoglobin levels below 110 grams per liter of blood set by WHO. Experts point out that this is due to the consumption of stagnant water containing zinc and magnesium. In the same area of Uzbekistan, from 1981 to 1987, liver cancer has increased by 200%, throat by 25% and infant mortality by 20%. Likewise, the cases of hepatitis, respiratory diseases, eye diseases and intestinal infections in the region are seven times higher than in 1960.
We are water

As you can see until this point, the future of the Aral Sea does not look promising. It is a catastrophe that could have been avoided. The existence of a disastrous governmental management of the lake basin became evident.

An effort to recover what was lost

An agreement was reached between the governments of several cities (Uzbekistan, Kazakhstan, Turkmenistan, Kyrgyzstan and Tajikistan) to set up a fund to carry out projects aimed at recovering The Aral sea, or at least to improve environmental conditions, called Executive Committee of the Aral Sea International Rescue Fund.

One of the initiatives that has been taken is the construction of the Kot-Aral Dam in the year 2005. Located at the mouth of the Sir Daria River, Is conformed by a stretch of 13 kilometers long that divides the old lake into two zones: the North Aral Sea and the South Aral Sea. This dam prevents the northern water from passing into the southern area, which has now become a huge desert. This has represented a hope of recovery for the north of the lake, but not for the south.

Kot-Aral Dam

With the construction of this structure there have been some beneficial changes in the biodiversity of the area. According to scientists who are dedicated to monitoring the evolution of lake, the most outstanding aspects in this improvement are:

The flow of the north lake has recovered 20% of its surface. The concentration of salt has fallen by half in a span of 10 years.
The vegetation in its surroundings is being reborn, a variety of aquatic plants and reed beds are already observed in the shallow water of the lake. This helps to offer a suitable habitat for birds and fish.
Fish species have increased to 20 today.

As the water returns, life also returns

Another important initiative is the Desert Reforestation Project in the southern zone, which seeks to reduce the environmental impact of desertification and begin a natural process of vegetation that extends through the desert.

According to the Ecologist Gaukarbek Satakep, director of the Natural Reserves of the Aral Region, the soil of the southern area is still a difficult medium for the planting of vegetation since the level of salinity is very high. It has begun with the planting of trees of Saxsaul since it adapts very well to the desert environments. This type of tree has the property of retaining moisture is its root, stem and leaves and also creates it around it, which allows it to survive without much water and collaborate in the growth of other wild herbs and plants that grow in its shade. The planting of these trees also seeks to reduce the impact of soil erosion.

Saxsaul plant

I hope these initiatives succeed in amending the natural damage caused. Hopefully one day the Aral sea will recover the lost space and with it return to this area of Central Asia the life and economic prosperity.

This is all I could research about this sad story. I thought it appropriate to share it, despite the magnitude of the disaster and the terrible consequences it has brought, until recently I ignored the fact. I suppose that many people also ignore it and I wanted to spread this information that I consider worrisome and important for the health of the planet.

If this information helps some people know more about the subject, I will have achieved my goal. In the references I leave some links of videos of documentaries about the Aral Sea, if you have time to see them, I recommend them so you can better appreciate the magnitude of the disaster.

Happy day, dear friends!