Despite protection measurements and their natural position, groundwater resources are very vulnerable due to natural and anthropogenic impacts. This is especially emphasized in karst arid and semi-arid zones, due to increased requirements for water. Paper deals with the impacts of the sinkholes on groundwater quality on Abarkooh city in Iran. There are 28 sinkholes located in Abarkooh plain. The aims of the paper are to specify the characteristics and causes of sinkholes occurrence, as well as to specify the vulnerable areas and future development of sinkholes and their effect on the groundwater resources. Next step is defining of the original procedure for protection of groundwater resources in characteristic areas, as karst arid and semi-arid areas are. By taking into the account geological, hydrogeological and meteorological data, and finally through hydrogeochemical and geophysical analysis, final conclusions and recommendations for the protection of the groundwater resources are obtained. This has significant importance for water supply of the Abarkooh city in Iran. It should be noted that the mentioned methodology for the protection of groundwater resources could be applied in other arid and semi-arid areas.

Unpredictable climate changes are affecting water resources, especially in karst arid and semiarid areas. In such locations, the need for additional sources of water always arises. The paper gives insight into hydrogeological characteristics of Kazeroo County and resolves some unknowns around the catchment area of the springs important for water supply of the wider urban area of the city of Kazeroon, Iran, by using stable isotope analysis (δD and δ¹⁸O) and tracer test. Multiple tracer test and stable isotope analysis were conducted for research purposes. The uranine injected at Tale Milek 1 borehole was detected in the Chenar Shahijan spring in less than 2 and in the Seyed Hossein spring after 6 days. Small amounts of uranine were detected in the Sasan and Pirsabz springs. Based on the high apparent flow velocity (approximately 1750–2000 m/day), the underground system has a quick response to the precipitation during dry seasons. The assumed hydraulic connection between Shahneshin North (Asmari) and Dashtak Northzones has been confirmed by tracer test since the dye injected in Northern Asmari Shahneshin anticline appeared in the springs in Dashtak North zone. The results of water stable isotope measurements show that the catchment area of karst springs in the vicinity of Kazeroo is probably over 2000 m at the area of Shahneshin anticline and is positioned lower than the catchment area of Arjan spring.

Iran is a land of complex geological past which reflects in its many natural wonders. There are more than 850 known caves in Iran with a total length not exceeding 1000 km, many of them not being properly explored. Two of the biggest and most famous caves are Ali-Sadr and Katale-Khor. The Katale-Khor cave has a simple maze anastomotic pattern. Ghar Ali-Sadr is an anastomotic type of cave located 75 km northwest of Hamedan in a village by the same name and circa 60 km south of Katale-Khor cave. Ali-Sadr cave is considered to be one of the most unique and scenic caves in the world. One of the features that makes Ali-Sadr cave special is a fact that it is the longest and the biggest water cave in the world (from the point of the boating course inside the cave). This natural wonders in Northern Iran are great base for developing a geotourism, as a form of tourism that specifically focuses on geology and landscape. Its purpose is to promote an understanding of earth sciences through appreciation and conservation of geodiversity. The best way to achieve this is through visits to geological features and locations.

The fractured karstified rocks covering more than 90% of the territory of the Zagros Range (Iran), which makes well-developed karst aquifers the main hydrogeological characteristic of the range, are investigated. It is shown that the increased demand for freshwater has led to the need for new studies of karst waters in the Zagros region. It is revealed that the presence of surface and subsurface karst features and strong discharge from springs feeding the alluvial aquifer make the Iranian Zagros Range a unique hydrogeological region. It is established that the primary porosity of limestone and intensive fracturing caused by tectonic activity facilitate the groundwater flow in karst areas. It is concluded that the study of the karst hydrogeology features in Zagros will lead to a better understanding of karst aquifers overall and help overcome the problem of drinking water shortage in the region. Accurate and complete data on the number of wells, springs, and extraction sites, as well as the volume of water extracted from these reservoirs, are necessary to ensure the protection and preservation of these resources.