The hydrogeochemical investigation of groundwater of Gezin (Elazığ) district

The subject of this thesis is to determine the hydrogeochemical features of the groundwater of Gezin (Elazığ) and its close vicinity. The aims of the study are (i) to investigate the physicochemical features of groundwaters, (ii) to determine the relations and origin of the groundwaters (iii) to determine their suitability for drinking and irrigation and (iv) to evaluate the waters in terms of pollution. For these purposes, the groundwater samples have been collected from the springs, wells and fountains in dry and rainy seasons in the studied area. Chemical and isotopic analyses of the water samples have been performed within the scope of the study. The results of the chemical analysis have been evaluated by using various diagrams and have been compared with the standarts to determine their suitability to drink, and irrigation purposes. From bottom to top, Upper Jurassic-Lower Cretaceous Guleman Ophiolite, Maastrichtian-Early Eocene Hazar Group, Middle Eocene Maden Complex, Plio-Quaternary alluviums and Holocene alluviums are outcropped in the studied area. The disturbed samples have been taken from the alluvium for testing their permeability at the laboratory. The permeability coefficient of the alluvial material have been measured by constant pressure permeameter and perforated base box method. The porosity of the alluvium have been determined by the compaction method at the laboratory. The water-table maps of the alluvium have been drawn related with the groundwater levels that had been measured in the wells in dry and rainy seasons. General groundwater flow direction also has been determined on the water-table maps. The temperature, pH and electrical conductivity of the investigated groundwaters range between 14oC and 21,3oC; 6,7 and 7,9; 418 μS/cm and 925 μS/cm, respectively. The Lake Hazar's water has been also sampled in October (2014) for the chemical and isotopic analyses. These analyses have been made for determining if there is any interaction occur between allivium aquifer groundwater and Lake Hazar' water. The pH and electrical conductivity of Hazar Lake is measured 9,0 and 2260 μS/cm, respectively. The chemical analysis results of the investigated waters have been evaluated by Piper, Scholler, Wilcox, USA Salinity Laboratuary and pie diagrams .The dominant cation is Ca+2 and dominant anion is HCO3 in the investigated groundwaters and the waters have been grouped as CaCO3- and MgCO3- rich waters on the Piper diagram The dry and rainy term variations of NH4 and NO3 of the waters have been investigated within the scope of the thesis. The NH4 and NO3 concentrations of the investigated groundwaters have been correlated with the drinking water standarts and possible reasons of the high and/or close NH4 and NO3 contents have been explained. The 2H (deuterium), 3H (tritium) and 18O (oxygen 18) analyses of the waters have been made in October to determine the origin, the residence and circulation time of the waters and to determine the relationship between groundwaters and the Lake Hazar' water.