Hydrochemical assessment of groundwater utilizing statistical analysis, integrated geochemical methods, and EWQI: a case study of Laiwu region, North China

Environ Monit Assess. 2024 Nov 19;196(12):1222. doi: 10.1007/s10661-024-13359-7.

ABSTRACT

The investigation of groundwater quality and hydrochemical assessment holds immense significance in safeguarding and ensuring the rational utilization of groundwater resources. This study utilizes groundwater sampling and testing data from the Laiwu region (LWR), encompassing both dry and wet seasons, to delve into the hydrochemical characteristics, ion sources, and overall groundwater quality. The research findings indicate that the groundwater in LWR exhibits weak alkalinity, with the dominant ions being Ca²⁺ followed by Mg²⁺, Na⁺, and K⁺, and HCO₃^–, SO₄^2-, NO₃^–, Cl^–, and F^–. The average total dissolved solids (TDS) concentrations during the dry and wet seasons are recorded as 683 mg/L and 679 mg/L, respectively, classifying LWR’s groundwater primarily as hard-fresh water. The spatial pattern of TDS concentration in LWR displays consistency throughout both the dry and wet seasons, with relatively low TDS levels observed in the northern and southeastern regions and higher concentrations in the lower reaches of the Dawen River and nearby Gangcheng. Predominantly, Ca²⁺, Mg²⁺, and HCO₃^– ions in groundwater originate from the dissolution of calcite and dolomite, with the hydrogeochemical process of carbonate rock weathering involving the presence of sulfuric acid. It is noteworthy that human activities significantly impact the chemical composition of groundwater in LWR. Notably, during the dry and wet seasons, the average concentration of NO₃^– in groundwater is 102.81 and 106.61 mg/L respectively, and the analysis shows that agricultural practice is the main source. Furthermore, the calculated average values of the entropy water quality index (EWQI) during those seasons are 58.44 and 57.24, respectively. The EWQI shows good to moderate water quality in most areas, except for a few poor-quality spots in the west. It is worth mentioning that LWR’s groundwater is deemed suitable for agricultural irrigation. These research findings provide valuable insights and serve as a significant reference for the rational development and sustainable utilization of groundwater resources in the LWR region.

PMID:39562385 | DOI:10.1007/s10661-024-13359-7