Characterizing water distribution and flow patterns controlled by the Tan-Lu Fault zone in Anhui province

The Tan-Lu Fault zone in Anhui province, China. This study systematically analyzed the regulatory effect of fault zone on the distribution and runoff characteristics of regional shallow groundwater and river system, and revealed the control mechanism of the fault structure on the hydrological system. The findings indicate that drainage basins (Huaihe, Chaohu, Caizihu, and Wanhe) controlled by the Tan-Lu Fault zone in Anhui Province have differentiated shallow groundwater flow fields. Shallow groundwater in each drainage basin converges towards the low-lying basins formed by the fault zone and eventually flows into the main river system. Due to the influence of the fault zone, the aquifers structure of regional shallow groundwater has significant spatial heterogeneity characteristics. The Huaihe and Chaohu drainage basins are dominated by pore water in unconsolidated sedimentary rock with high water-yielding property; the Caizihu and Wanhe drainage basins are dominated by fracture water in bedrock with significant differentiation in water-yielding property. The activity of the Tan-Lu Fault zone has caused many rivers in the study area to exhibit a significant movement at the vertical intersection with the fault zone, having displacement distances ranging from 290 m to over 2000 m. The above studies systematically reveal the coupling relationship between fault structure and hydrological system, providing a scientific basis for regional water resource research. • Shallow groundwater flow fields characteristics in four drainage basins was revealed. • Clarify the differences in aquifer structure of different drainage basins. • Displacement values of fault zones on the river systems were quantitatively revealed. • Controlling effect of the fault zones on the hydrological system was disclosed.