Pumping tests analyses of a heterogeneous pore aquifer based on the Generalized Radial Flow model

Abstract

Classical models such as the Theis model and Dupuit model have certain limitations in analyzing pumping test data of heterogeneous aquifers, and the obtained parameters are not suitable for characterizing the heterogeneous aquifers. The GRF model, however, can obtain the data of flow characteristics of aquifers, which can better characterize the characteristics of heterogeneous aquifers than the Theis model and Dupuit model do. Based on the pumping test data of the Qianchenzhou Yangtze River Bridge in East Lake New Village of Huangshi, the Theis model and GRF model are used to calculate the aquiferous water flow dimension and the apparent hydraulic diffusion coefficient (Kf /Ssf ), and the hydrological geological parameters calculated by different methods are combined with the actual hydrological geological conditions. The results show that the aquifer in the study area is a heterogeneous aquifer with fine sand intercalated with banded clay lens, so it is more reasonable to use the GRF model to calculate the parameters. The coefficient of permeability is 4.09×10−3 cm/s, and the flow dimension is 1.61. The flow regime is equivalent to the bilinear one, and the aquifer response to pumping is governed by the clay strip. The non-linear correlation of Kf /Ssf between the observation wells and pumping wells further confirms the heterogeneity of the aquifers. In the heterogeneous pore aquifers, the application of the porous combined unstable GRF well flow test method can not only determine hydrogeological parameters, but also enrich the cognition of aquifer characteristics.

Keywords

• heterogeneous porous medium
• pumping test
• coefficient of permeability
• grf model
• flow dimension