Groundwater quality evaluation model based on set pair analysis and its application

Evaluation of groundwater quality has an important role in groundwater management and conservation. Addressing the uncertain characteristics of groundwater quality as affected by multiple interacting factors – and the factors being changeable, random and fuzzy – sample test data from 20 hydrogeologic boreholes in a study area in Fenggang town, Zunyi city, China were collected and a groundwater quality evaluation model was built based on set pair analysis. Through expressions of the connection degree and decomposition of the degree of discrepancy and calculation of the comprehensive fuzzy connection degree, results of groundwater quality evaluation in the study area were obtained. The reliability and validity of the model were proved by comparing the results with the actual situation. This new groundwater quality evaluation method reflects the characteristics of groundwater quality controlled by multiple factors and factor uncertainty.