Assessment of groundwater quality for irrigation purposes and identification of hydrogeochemical evolution mechanisms in Pengyang County, China

• Published in: Environmental earth sciences 2013-08, Vol.69 (7), p.2211-2225
• Main Authors: Li, Peiyue, Wu, Jianhua, Qian, Hui
• Format: Article
• Language: English
• Subjects: Alkalinity; Anions; Assessments; Biogeosciences; Calcite; Cations; Dissolution; Dolomite; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Environmental Science and Engineering; Evolution; Evolutionary biology; Exact sciences and technology; Geochemistry; Geology; Ground-water quality; Groundwater; Groundwater irrigation; Gypsum; Hydrogeology; Hydrology. Hydrogeology; Hydrology/Water Resources; Irrigation; Irrigation water; Mathematical models; Mineralogy; Minerals; Original Article; Quality; Silicates; Terrestrial Pollution; Total dissolved solids; Water geochemistry; Water quality assessments; Water resources; Weathering
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-012-2049-5

Groundwater is an important water source for agricultural irrigation in Penyang County. Some traditional methods such as irrigation coefficient, sodium adsorption ratio, total alkalinity, total salinity and total dissolved solids were employed to assess groundwater quality in this area. In addition, an improved technique for order preference by similarity to ideal solution model was applied for comprehensive assessment. The origin of major ions and groundwater hydrogeochemical evolution was also discussed. Groundwater in Penyang County contains relative concentrations of dominant constituents in the following order: Na +  > Ca 2+  > Mg 2+  > K + for cations and HCO 3 −  > SO 4 2−  > Cl −  > CO 3 2− for anions. Groundwater quality is largely excellent and/or good, suggesting general suitability for agricultural use. Calcite and dolomite are found saturated in groundwater and thus tend to precipitate out, while halite, fluorite and gypsum are unsaturated and will dissolve into groundwater during flow. Groundwater in the study area is weathering-dominated, and mineral weathering (carbonate and silicate minerals) and ion exchange are the most important factors controlling groundwater chemistry.