Meng Mao Xia Wang Xueqin Zhu
The east foothill of the Taihang Mountains, Hebei Province, is an important groundwater recharge and transport area in the North China Plain. It is of practical significance to study the groundwater hydrochemical characteristics of this area for rational groundwater regulation. In this study, the Chadha rectangular diagram and Piper trilinear diagram were adopted to identify the relevant hydrochemical processes, and the main groundwater hydrochemical type was the HCO3·SO4–Ca. Descriptive statistical methods, correlation analysis, major ion ratio determination and principal component analysis (PCA) were employed to analyze the formation mechanism of groundwater hydrogeochemical characteristics and to identify the sources of the main groundwater ions in the study area. The results showed that Ca2+ and HCO3− were the dominant groundwater cation and anion, respectively, and the Gibbs diagram demonstrated that the majority of groundwater samples occurred in the rock weathering-dominated area. Bivariate diagrams revealed that mineral dissolution and ion exchange controlled the groundwater geochemistry. The study area was seriously polluted by NO3–, which might be due to the application of farmland fertilizers and leakage of rural domestic sewage and garbage. PCA yielded three principal components (PCs), which represented processes influenced by salinity, human activity and fluoride impacts on the groundwater chemistry. The distribution of high-positive PC scores verified the influences of the various processes on the groundwater study area, which is an effective tool to formulate and implement management strategies for the sustainable development of groundwater areas.
Hydrochemistry; Chadha’s diagram; Principal component analysis; Source apportionment; Spatial distribution