| چکیده انگلیسی مقاله |
Karst groundwater resources have been important for thousands of years. A large part of the urban and rural population is extremely dependent on karst water resources. In general, 20-25% of the world's population is largely or completely dependent on karst aquifers. In some European countries, karst water sources provide 50% of the total drinking water, and in many areas, only fresh water is available. More than 85% of the southern regions of Iran also supply their water needs from karst water sources. Karst springs have been more important than other karst features so that in all karst areas, many of the most primitive villages and towns have been concentrated in their vicinity. Significant expansion of karst formations, especially carbonate formations in the geological zones of Zagros, Kopeh-Dagh, Alborz and a limited extent in the central regions of Iran, create suitable conditions for the formation of karst landforms and significant karst groundwater reservoirs in the country. Famous carbonate formations such as Asmari, Jahrom, Shahbazan, Tarbour and Sarvak in the Zagros geological zone, Mozduran and Tirgan in the Kopeh Dagh, Lar and Elika and Cretaceous limestones in the Alborz zone and significant Cretaceous carbonate outcrops in Central Iran has provided favorable conditions for the formation of important karst groundwater reservoirs, so that now it provides drinking water to many small and large cities of the country. Due to population growth and the importance of providing the required water, karst water resources are discharging highly and water level into the aquifer is dropping extremely. On the other hand, the irregular distribution of rainfall in Iran causes that a significant part of the runoff be removed without any uses and in some cases also cause great damage; this state occurs in the Zagros geological zone more than other regions. One way to deal with this risk is artificial recharge into carbonate formations. Since the carbonate formations of Iran, especially in the Zagros geological zone, have a lot of fractures and cracks and are very permeable as a result, the most of the rainfall infiltrate into the formations. Therefore, these formations can be considered the best place for artificial recharge and forced infiltration of excess surface water; So that by transferring flooding runoff in the rainy season (when the water flow is not much needed) and part of the river flow in the season when there is no rain, the karst aquifer can be fed and improved. For this purpose, criteria and indices should be determined and areas prone to artificial recharge should be identified based on that. The most important effective indices in this regard are the fracturing (faults and lineaments) conditions and the presence of springs in the watershed; So that the areas with the most fractures are very prone to infiltrate the surface flows. Whereas the spring is the point of aquifer discharge so the areas with a large number of springs are not suitable for artificial recharge of carbonate aquifers. Artificial recharge potential mapping on carbonate aquifers, therefore, should be used to determine the exact location of the project to increase the karst water level in the areas affected by the water crisis. |
