The Charactristic of Endokarst in the Bed Rock of Hamdens inkholes Area
|Location||21th symposium on geosciences|
|Holding Date||21 May 2008|
The plain of Famenian, Kaboudar-Ahang, Ghahavand located in the north of Hamedan province that the sediments thickness of its aquifer is about 70-100 meters. In recent years the big and dangerous sinkholes have been appeared in this area. By the result of excavations that done in this plain and investigation of the outcrops around it, it was found that the bed rock of this area has been made from Oligo-Miocene limestone.
According to the field observation, the measuring of joints and fractures systems, studying the thin sections, characteristics of excavations, yield of wells, the results obtained by chemical experiments of water and the estimation of parameters such as saturation index, stability index, the amount of free carbon dioxide and the primary pressure of carbon dioxide gas, It concludes that the karstification phenomenon was happened in the bed rock and the endo-karst structures exist in it. Therefore, good yield of wells and occurrence of undesirable phenomenon such as sinkholes depend on this structure.
In order to avoid or reducing the occurrence rate of sinkholes in this area, we should avoid digging in the bed rock and should stop the pumping of well which have been drilled in the bed rock and have high yield.
Keyword: Hamedan, Famenin, Ghahavand, Kaboudar-Ahag, Karst, Groundwater, Sinkhole