Māris kļaviņŠ, azamat azizov, JĀnis zaļoksnis environment, pollution, development: the case of uzbekistan

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ENVIRONMENT, POLLUTION, DEVELOPMENT:  THE CASE OF UZBEKISTAN
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The process of eutrophication is based on creating optimal 
conditions for the development of aquatic organisms, which 
normally requires micro-and macro-elements. If the elements such 
as carbon, hydrogen, calcium and magnesium are always excessive 
in natural waters, in reality the development of living organisms is 
decided by biogenic elements: nitrogen compounds, silicon, but first 
of all, phosphorus. Consequently, discharge of household sewage and 
other wastewater, and also entry of surface runoff from agricultural 
areas in watercourses, start off the eutrophication process. The fact 
that the eutrophication processes are first of all determined by the 
presence of phosphorus compounds is proved by the dependence of 
algae growth on the presence of phosphorus compounds in water. 
Nitrogen is the limiting element in eutrophication considerably less 
frequently and it is typical first of all of the marine waters.
The causes of eutrophication are as follows:
1.  lake water level decline during excessive lake exploitation;
2.  rapid  filling  of  lakes  with  sludge  containing  silt  from  the  soil 
erosion in the catchment area (deforestation, agriculture); 
3.  direct  eutrophication  as  a  result  of  diffuse  or  point  source 
nutrient inflow.
Figure 8.7. 
The process 
of lake evolution 
and overgrowing.