Characterize hydraulic properties of fault zone using pumping test data
and electrical resistivity data in Xinchang Region, China
Abstract
Obtaining the hydraulic conductivity characteristics of widely
distributed fault zones is the key to evaluating potential underground
nuclear waste repositories. However, there are currently certain
limitations on the methods for such data collection. In this study,
electrical resistivity tomography (ERT) was combined with pumping test
data to obtain the distribution of hydraulic conductivity in fault
zones. The hydraulic conductivity of the aquifer was obtained through 30
pumping tests in seven pumping wells, and the results were then fitted
with the aquifer resistivity obtained by the ERT at the corresponding
positions to establish the relationship between the resistivity and the
hydraulic conductivity, according to which the hydraulic conductivity
characteristics of the fault zone can be obtained using the resistivity
value. The results show that for the sandstone area with a small
hydraulic conductivity, the result of exponential fitting is more
accurate (R2 = 0.97) than that of linear fitting and power fitting. The
hydraulic conductivity calculated based on the established R-K
relationship has an error of less than 10.50% compared with that
measured by the pumping tests, and the Nash-Sutcliffe efficiency
coefficient is 0.96. Furthermore, the spatial distribution of the
hydraulic conductivity of the fault zone in the study area was
calculated based on this relationship, providing a basis for more
accurate and low-cost descriptions of groundwater and solutions
transport in the fault zone.