عنوان مقاله [English]
Limited and polluted fresh water resources are among the main problems and crisis the world and especially Iran face now and in future. Many natural and human related factors make Iran limited water resources polluted and unusable. One of the main problems of fresh water resources is that different natural factors make them polluted and salty. Many rivers in Iran have a satisfying water quality at the source of river, but they deteriorate due to some factors in their course or at the estuary. Many natural factors, like salty geological structures, salt domes, long distance and washing sediments of different formations, very high temperature and evaporation, etc. are involved in salinization of these rivers. Because of geological and geographical situations, salt domes are observed in many parts of the country, especially in center, South and North West of Iran, and they can be considered one of the most important factors. Hable rud in Garmsar, Aji Chay (Talkhe rud) in Azarbaijan, Dehrom (One of Rudmand tributary) in Fars, Dalaki and many other rivers face this problem. Every year, tons of salt and sedimentations are being washed from salt domes and formations and enter these rivers, changing the water quality. Implementing some practices, like changing the course of salty water or fresh water, preventing confluence of salty and fresh water rivers, canalizing fresh water rivers, etc. it is possible to revive and restructure these important and rare resources, so that the water will be at least usable for agricultural, industrial and construction projects in upstream and midstream.