Department of Civil Engineering, Tonekabon Branch, Islamic Azad University.
As result of density difference between seawater and fresh water in coastal aquifers, a transition zone between two fluids is formed. A wedge of saltwater can be entered in coastal areas to the aquifer. Seawater intrusion rate and extent of transition zone depends on several factors including: changes in sea level, aquifer characteristics, hydrologic conditions of upstream, discharging from the aquifer, tidal and seasonal fluctuations of sea water.
In this paper height of interface between seawater and freshwater in Mazandaran coastal aquifers is calculated by relationships that have been used in previous researches. Then Babol– Amol aquifer has reviewed by using of existing data in Water Company of Mazandaran and past researches. According to the available information, the development of exploitation of three zones (Alashroud to Haraz, Haraz to Babolroud and Babolroud to Talar river in Amol- Babol aquifer in south of Caspian Sea) for distances less than 2000 m to sea is possible in the Haraz to Alash river. The total amount of water from this study to can be discharged in the three regions is 505 million cubic meters, based on available data. According to statistics, 458 million cubic meters of these three areas are allowed to be discharged. Therefore, taking into account the withdrawal of unallowable wells, it can be assumed that the saltwater intrusion has more than 2000 meters to the coast. The results of this study are based on the hydrodynamic parameters of the aquifer for the past 9 years and seawater intrusion may be aggravated by climate change and hydrodynamic parameters change of in this aquifer. Therefore, it is necessary to carefully study hydrodynamic parameters of this aquifer.