Hydrogeochemical Characterization and Its Seasonal Changes of Groundwater Based on Self-Organizing Maps

Abstract

Water resources are scarce in arid or semiarid areas; groundwater is an important water source to maintain residents’ lives and the social economy; and identifying the hydrogeochemical characteristics of groundwater and its seasonal changes is a prerequisite for sustainable use and protection of groundwater. This study takes the Hongjiannao Basin as an example, and the Piper diagram, the Gibbs diagram, the Gaillardet diagram, the Chlor-alkali index, the saturation index, and the ion ratio were used to analyze the hydrogeochemical characteristics of groundwater. Meanwhile, based on self-organizing maps (SOM), quantification error (QE), topological error (TE), and the K-means algorithm, groundwater chemical data analysis was carried out to explore its seasonal variability. The results show that (1) the formation of groundwater chemistry in the study area was controlled by water–rock interactions and cation exchange, and the hydrochemical facies were HCO3-Ca type, HCO3-Na type, and Cl-Na type. (2) Groundwater chemical composition was mainly controlled by silicate weathering and carbonate dissolution, and the dissolution of halite, gypsum, and fluorite dominated the contribution of ions, while most dolomite and calcite were in a precipitated state or were reactive minerals. (3) All groundwater samples in wet and dry seasons were divided into five clusters, and the hydrochemical facies of clusters 1, 2, and 3 were HCO3-Ca type; cluster 4 was HCO3-Na type; and cluster 5 was Cl-Na type. (4) Thirty samples changed in the same clusters, and the groundwater chemistry characteristics of nine samples showed obvious seasonal variability, while the seasonal changes of groundwater hydrogeochemical characteristics were not significant.

A Systematic Review of the Relationship between Geotechnics and Disasters

“…Consequently, the connection among author's keywords (Figure 8) denotes relationships between the clusters "earthquakes" and "risks" through studies of GIS applications in the management and evaluation of risks, landslide hazards, and liquefaction induced by earthquakes [134,200,245,338]. For example, the 2008 Wenchuan, China (magnitude M 7.9) and the 1999 Taiwan, China (magnitude M 7.6) earthquakes provided important information for the study of landslides induced by these seismic events in mountainous areas [339]. Additionally, a connection between "debris flows" and "landslides" was observed through studies on landslides and debris flows induced by rains [259], such as the case registered in Malaysia, whose major impacts (debris flows and landslides) were related to geotechnical faults.…”

Hydrochemical Characteristics and Formation Mechanism of Quaternary Groundwater in Baoshan Basin, Western Yunnan, China

“…The Gibbs plots allow a preliminary judgment to be made: the hydrochemical genesis of groundwater in the study area is closely related to water-rock interaction. To illustrate the specific water-rock interaction process, the Gaillardet model needs to be invoked for a further explanation of the water-rock process [36]. The model has three different units of water-rock interaction along the diagonal of the rectangle from the lower left to the upper right corner for evaporite, silicate, and carbonate rocks, in that order.…”