Document Type : Research Paper
Authors
1 P.h.D Student of Hydrogeology, faculty of natural science, department of earth science, university of Tabriz
2 Professor of Hydrogeology, faculty of earth science, university of Tabriz
Abstract
the existence of about 6,000 wells in the plain and the extraction of groundwater resources has led to a sharp decrease in the water table and consequently, an increase in the salinity of the aquifer. For this purpose, 27 samples of Malekan water resources were collected and hydrochemical properties were analyzed. The results of the analysis were compared with the lake water sample with respect to the hydrochemical characteristics of the main elements. Salinity increasing and saltwater intrusion into the aquifer was investigated using geophysical methods, geochemical diagrams, as well as various ion ratios. The results showed that salinity increases in the aquifers around Urmia Lake is related to the low slope at the end of the plains and its ultra-fine grain sediments, which, as a result, when groundwater flow collide with such sediments, their movement slow down and water raised to the surface via capillary action. Finally shallow groundwater cause to intense evaporation and increasing groundwater salinity. Moreover, In addition, the distribution of surface currents in the ends of the plain leads to evaporation and the formation of salt crops, and high exploitation leads to the gradual flow of water to upstream of the aquifer. The presence of the salty sludge from ancient lakes beneath the alluvial and salts formations with high exploitation and decreasing of groundwater levels leads to upconing in the lower layers of clay formations and reaching the saltwater to the wells.
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