Hydrochemical Evolution and Quality Assessment of Groundwater in the Sanjiang Plain, China

Abstract

Groundwater is subjected to contamination threats from human activities, such as agriculture, especially long-term farming in the Sanjiang Plain, China. Identifying the sources and distribution of pollution is essential for its reasonable prevention and control. In this study, we analysed the chemical characteristics of 389 samples at 60 shallow groundwater monitoring points from 2011 to 2015 in the Sanjiang Plain using traditional hydrochemical methods, water quality assessment, Pearson’s correlation, and principal component analysis (PCA). Although groundwater type in this area was predominantly HCO3-Ca·Mg, three forms of nitrogen pollution (ammonia, nitrate, and nitrite) were all detected in this area. The interaction of natural geochemical and anthropogenic factors during hydrochemical formation is confirmed by the high coefficients of variation and Gibbs plots of the main ions in the water. The overall shallow groundwater situation was described as good, with more than 40% and 90% of groundwater samples suitable for drinking and irrigation according to the quality assessment, respectively. The proportion of poor water quality in the wet season was higher than that in the dry season. NO3-N and NH3-N were identified as the major anthropogenic pollutants in the study area. Results from Pearson’s correlation and principal component analysis shows two main pollutants fall into two chemical controlling factors together with natural chemical parameters, which implies that the migration and transformation of pollutants may have affected the overall hydrochemical characteristics of the regional groundwater. Therefore, findings from this paper can provide insight into the chemical evolution of groundwater in response to long-term agricultural activities and can help contribute to better management of groundwater resources and agricultural sustainable development.

Microcystin Concentrations and Detection of the mcyA Gene in Water Collected from Agricultural, Urban, and Recreational Areas in a Karst Aquifer in the Yucatan Peninsula of Mexico

“…It is interesting to point out that in this study recreational sites showed the typical homogeneous chemical composition of groundwater that has been previously reported in the YPM [52], whereas urban sites and agricultural sites showed more variability in their chemical composition [53]. Particularly, agricultural sites showed early salinization processes occurring as a result of water type changes from a Ca-Cl water type to a Na-Cl composition [54]; in addition, their highest concentration of nitrate can be most likely attributed to the agricultural influence and runoff from agrochemicals used in the area [53,55].…”

“…The significant differences found in this study could be attributed to three causes: the first, the geological characteristics of the aquifer matrix presenting different types of water; the second, the geographical proximity to the coast with the consequent influence of saline intrusion into groundwater [49,50]; and the third, the entry of nutrients as the result of anthropogenic-related activities [51]. It is interesting to point out that in this study recreational sites showed the typical homogeneous chemical composition of groundwater that has been previously reported in the YPM [52], whereas urban sites and agricultural sites showed more variability in their chemical composition [53]. Particularly, agricultural sites showed early salinization processes occurring as a result of water type changes from a Ca-Cl water type to a Na-Cl composition [54]; in addition, their highest concentration of nitrate can be most likely attributed to the agricultural influence and runoff from agrochemicals used in the area [53,55].…”

Analysis of Groundwater Overexploitation Based on Groundwater Regime Information

“…The main soil types are meadow soil, swamp soil (Zhang et al 2022), and black soil. Black soil covers an area of 11,101 km 2 in the study region, thereby accounting for 72.8% of the entire agricultural land (Ye et al 2022).…”

GIS and Index-Based Methods for Assessing the Human Health Risk and Characterizing the Groundwater Quality of a Coastal Aquifer

“…Among the most-used hydrogeochemical methods for surveying the evolution of groundwater quality and sources of groundwater recharge [Ye et al, 2022] is the Durov diagram [Durov, 1948] which enables the chemical composition of groundwater to be determined [Ahmed et al, 2020;Hui et al, 2021]. The spatial distribution maps were performed using the interpolation algorithm of Kriging and the Qgis 3.16 for the automatic mapping.…”