Analysis of Aquifer Test Data in Fractured Aquifers and the Application of the Generalized Radial Flow

Data from 122 pumping tests were obtained from 100 boreholes in granites, volcanic rocks, metamorphic rocks, and Cretaceous and Tertiary sedimentary rocks, and then were analyzed using AQTESOLV. Results from 86 of the 122 tests (71%) have an analytical solution corresponding to Theis (1935), Cooper-Jacob (1946), Papadopulos-Cooper (1967), Hantush (1962), Moench (1985), or Hantush-Jacob (1955), whereas the remaining 36 results (29.5%) do not correspond to any of the analytical methods. Of the 86 results, only 17 match the Theis and Cooper-Jacob methods, indicating that the basic methods for pumping test analysis are useful for only 14% of the total data. This suggests that analytical solutions derived using leaky boundary conditions are appropriate for the analysis of pumping test data in fractured aquifers in this study. Furthermore, the results show the importance of carefully selecting an appropriate model for the analysis of pumping test data. Results from the 122 pumping tests were also analyzed using the GRF model. Using the Barker method, the results show that 77 of the 122 tests (63%) have dimensions ranging between 1.1-2.9. Of these 77 solutions, 39(44.2%) have a fractional dimension of 1.1-1.9, 26(6.5%) show 2-dimensional radial flow also applicable to the Theis method, and 38(49.3%) have dimensions of 2.1-2.9. The results show that groundwater flows according to a fractional flow dimension in fractured aquifers.