Hydrochemical characterization and pollution sources identification of groundwater in Salawusu aquifer system of Ordos Basin, China.
Ordos Basin is located in an arid and semi-arid region of northwestern China, which is the most important energy source bases in China. Salawusu Formation (Q3 s) is one of the most important aquifer systems of Ordos Basin, which is adjacent to Jurassic coalfield areas. A large-scale exploitation of Jurassic coal resources over ten years results in series of influences to the coal minerals, such as exposed to the oxidation process and dissolution into the groundwater due to the precipitation infiltration. Therefore, how these processes impact groundwater quality is of great concerns. In this paper, the descriptive statistical method, Piper trilinear diagram, ratios of major ions and canonical correspondence analysis are employed to investigate the hydrochemical evolution, determine the possible sources of pollution processes, and assess the controls on groundwater compositions using the monitored data in 2004 and 2014 (before and after large-scale coal mining). Results showed that long-term exploration of coal resources do not result in serious groundwater pollution. The hydrochemical types changed from HCO3(-)-CO3(2-) facies to SO4(2-)-Cl facies during 10 years. Groundwater hardness, nitrate and sulfate pollution were identified in 2014, which was most likely caused by agricultural activities.
Key Laboratory of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130021, PR China. Electronic address: qyang@udc.es.
Qingchun
Q
Yang
Key Laboratory of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130021, PR China.
Luchen
L
Wang
Key Laboratory for Groundwater and Ecology in Arid and Semi-arid Areas, Xi'an Center of Geological Survey, CGS, Xi'an, PR China.
Hongyun
H
Ma
School of Water Resources and Environment, China University of Geosciences Beijing, Beijing, 100083, PR China.
Kun
K
Yu
Escuela de Ingenieros de Caminos, Universidad de A Coruña, Campus de Elviña, 15192, Spain.
Jordi Delgado
JD
Martín
D000383:Agriculture; D002681:China; D003032:Coal Mining; D004784:Environmental Monitoring / Q000379:methods; D060587:Groundwater / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis / Q000737:chemistry; D013431:Sulfates / Q000032:analysis / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
D009566:Nitrates; D013431:Sulfates; D014874:Water Pollutants, Chemical
Groundwater; Hydrochemical; Ordos basin; Pollution factor