Hydrochemical characteristics and the effects of irrigation on groundwater quality in Harran Plain, GAP Project, Turkey

• Published in: Environmental earth sciences 2008-03, Vol.54 (1), p.183-196
• Main Authors: Yesilnacar, M. Irfan, Gulluoglu, M. Said
• Format: Article
• Language: English
• Subjects: Ammonium; Arid zones; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Exact sciences and technology; GAP Project; Geochemistry; Geology; Groundwater; Groundwater irrigation; Groundwater quality; Harran Plain; Hydrogeology; Hydrology. Hydrogeology; Irrigation; Irrigation effects; Magnesium; Mineralogy; Organic carbon; Organic phosphorus; Original Article; Salinity; Silicates; Surface irrigation; Turbidity; Turkey; Water analysis; Water geochemistry; Water hardness; Water quality; Water resources; Water sampling
• ISSN: 0943-0105; 1866-6280; 1432-0495; 1866-6299
• DOI: 10.1007/s00254-007-0804-9

Improper design, faulty planning, mismanagement and incorrect operation of irrigation schemes are the principle reasons for the deterioration of groundwater quality in a large number of countries, in particular in semi-arid and arid regions. The aim of this study is to determine the dimensions of groundwater quality after surface irrigation was begun in the semi-arid Harran Plain. Physical and chemical parameters of the groundwater including pH, temperature, electrical conductivity (EC), sodium, potassium, calcium, magnesium, chloride, bicarbonate, sulphate, nitrate, nitrite, ammonium, total phosphorus, total organic carbon and turbidity were determined monthly during the 2006 water year. The quality of the groundwater in the study area was assessed hydrochemically in order to determine its suitability for human consumption and agricultural purposes. In the general plain, the EC values measured were considerably above the guide level of 650 μS/cm, while nitrate in particular was found in almost all groundwater samples to be significantly above the maximum admissible concentration of 50 mg/l for the quality of water intended for human consumption as per the international and national standards. Total hardness reveals that a majority of the groundwater samples fall in the very hard water category. Interpretation of analytical data shows that Ca-HCO₃ and Ca-SO₄ are the dominant hydrochemical facies in the study area.