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

Abstract

Aggressive recharge water is capable of widening the surface and interior openings of karstic layers that leads to the easy flowing of water in this type of aquifers. The object of this study is to understand if surface karstification is the same as the interior karst development of an aquifer. Surface karstification was analyzed using Geographic Information System and remote sensing techniques, while interior karstification was studied with spring hydrograph analysis. The study area includes seven carbonate aquifers in the Zagros Region of Iran. The surface karstification of these aquifers is 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 presence and density of faults and fractures; while the least significant factor is the vegetation cover. The spring hydrograph analysis shows that there are different ways of estimating the relative karst development, but each parameter that impacts the specific character of the karst aquifer might be independent of others. Furthermore, comparing the relative surface 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 a meaningful concept and comparison among different aquifers throughout the world.

Using Stable Isotope Analysis (δD and δ18O) and Tracing Tests to Characterize the Regional Hydrogeological Characteristics of Kazeroon County, Iran

“…According to the volume of the pores and the openings of the rocks and according to the calculations, the infiltration rates for the Sarvak and Asmari formations are 36.5% and 39.6%, respectively [29]. Sasan spring is dominated by a quick-flow response and in high karst development based on the high ratio of α1 to α2 [37].…”

“…Five alluvial subaquifers (Shapur, Kazerun, Famour-Parishan, and Chenar Shahijan) have developed in syncline valleys. The karst aquifers of Zagros have been the subject of numerous research studies with the aim of a better understanding of the complex geological and hydrogeological relationships that prevail in the area [30,[36][37][38]. Kazeroon County consists of several karst zones which developed mainly due to The most significant water resources in the Zagros Mountains area are karstic aquifers, which outcrop over 20 percent of the Zagros surface.…”

“…The karst aquifers of Zagros have been the subject of numerous research studies with the aim of a better understanding of the complex geological and hydrogeological relationships that prevail in the area [30,[36][37][38]. Kazeroon County consists of several karst zones which developed mainly due to the dissolution of carbonate rocks-Bushigan, Sarbalesh, Salbiz, Dashtak, and Naser Abad karst zones [39].…”

“…The retention capacity of karst subaquifers is relatively good with a somewhat long residence period [39]. Aquifers formed in the Asmari Formation vary in hydraulic characteristics and behavior and have been an object of interest of many scientific studies [28,30,37]. Asmari and Sarvak are crucial karst formations and create the largest karst aquifers and reservoirs with numerous spring discharges.…”