An integrated hydrogeological approach to evaluate the leakage potential from a complex and fractured karst aquifer, example of Abolabbas Dam (Iran)

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Rouhollah Adinehvand - , Shiraz University (Author)
  • Ezzat Raeisi - , Shiraz University (Author)
  • Andreas Hartmann - , University of Bristol (Author)

Abstract

The design and construction of dams are risky in karst regions with active tectonic settings and strong heterogeneity due to their leakage potential. Hydrogeological characterization by karst-specific methods can be used to reduce the risk of improper dam construction. Numerous karstic dams have been constructed in the world in simple tectonic settings. In this study, a combination of geological and hydrogeological investigations is used with extensive data collection to evaluate the leakage potential of the Abolabbas Dam construction project at the Malagha karst aquifer, a tectonized highland karst region in the southwest of Iran. Two thrust faults which bounded the Malagha karst aquifer (overthrusting) caused extensive crushed zones, continuous lengths with high permeabilities in most of the boreholes, extensive open joints, and small-size solution cavities. The results of artificial tracer tests imply that the flow regime is diffuse. The flat water table, diffuse flow regime, extensive crushed zones, and continuous high-permeabilities most probably imply that the groundwater flows through an extensive network of joints without main conduits to drain the system. Despite a diffuse flow regime, an extensive grout curtain both in length and depth is required to prevent leakage because the loose materials of the crushed zones will be washed out without it under high hydraulic gradients after dam impoundment. The impermeable formation is too deep due to overthrusting. Therefore, a huge leakage may occur under the hanging grout curtain. The results allow a clearer understanding of the location and properties of fracture zones, erodible materials, high permeability zones, groundwater flow regime, and zones of preferential flow which are essential for reducing the failure of dam construction in such environments. Overall, it is demonstrated that integrating different complementary methods can help to minimize the uncertainties inherent in engineering problems in similar karst scarce-data regions.

Details

Original languageEnglish
Article number501
JournalEnvironmental earth sciences
Volume79
Issue number22
Publication statusPublished - 1 Nov 2020
Peer-reviewedYes
Externally publishedYes

External IDs

ORCID /0000-0003-0407-742X/work/142242580

Keywords

Keywords

  • Diffuse flow, Fractured karst aquifers, Iran, Leakage potential

Library keywords