Methods for groundwater quality and pollution assessment are applied extensively, but it is difficult to determine a unified evaluation model. On the basis of hydrogeochemical characteristics analysis in 2016 compared with that in 1995, the five-element connection number SPA (set pair analysis) method was applied to evaluate the groundwater quality of the Gaoqiao diluvial fan under the influence of hydrogeological conditions and human activities along the flow path in our work. Descriptive

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... stics methods, Piper diagram, and a Schoeller diagram were also used to analyze the hydrochemical characteristics of groundwater such as chemical components, total dissolved solid, and total hardness. The change of the typical pollutant of fluorine was analyzed to evaluate the groundwater quality under the influence of human activities. The results showed that the groundwater quality in the study area was more in rank П. The basic hydrochemical types of shallow groundwater were HCO3-Ca·Mg and HCO3·SO4-Ca·Mg. The influencing factors of the hydrochemical component of groundwater were identified in the Gaoqiao diluvial fan. The quality of groundwater changed slightly from the top to the edge of the fan due to the water–rock interaction except for in Yucun and Hucun influenced by human activities. The assessment result can provide a scientific basis for the pollution prevention and changing process control of the groundwater in the hydrogeological unit of the Gaoqiao diluvial fan.