Comparison of surface and interior karst development in Zagros Karst Aquifers, Southwest Iran

摘要

Aggressive recharge water is capable of widening the surface and interior openings of karstic layers that leads to theeasy flowing of water in this type of aquifers. The object of this study is to understand if surface karstification is thesame as the interior karst development of an aquifer. Surface karstification was analyzed using Geographic InformationSystem and remote sensing techniques, while interior karstification was studied with spring hydrograph analysis. Thestudy area includes seven carbonate aquifers in the Zagros Region of Iran. The surface karstification of these aquifersis controlled by different factors including the thickness of carbonate formations, distance from faults, fracture density,precipitation, temperature, vegetation index, slope, and relief. The most important factors are precipitation and presenceand density of faults and fractures; while the least significant factor is the vegetation cover. The spring hydrographanalysis shows that there are different ways of estimating the relative karst development, but each parameter thatimpacts the specific character of the karst aquifer might be independent of others. Furthermore, comparing the relativesurface and interior karst development demonstrates that the possible relationship between them is unpredictable.Consequently, we define a specific and unique numeric method to assess the interior karst development that permits ameaningful concept and comparison among different aquifers throughout the world.