Environmental effects of coastal dikes on shore soil salinity

One of the subjects that should be considered in coastal dykes design is interaction of saltwater and freshwater in the body and under the dykes. This paper evaluates the effect of clayey blanket and vertical cutoff on freshwater and saltwater interaction in the body and under the dyke by using CTRAN/W finite elements model. This model has developed during 2001 at Alberta Canada for studying on movement of contaminants such as salt and polluter particles through porous materials. In this study, five analyses group have been performed. First group was studying on status of salt invasion promotion after the dyke constructing and before filling from river water. Second group was after filling of dyke side to 3.5 meters height. Third group analysis was the same as second group but using clayey blanket instead. Fourth group was analysis was the same as second group but using vertical cutoff instead, and fifth group was using conjointly clayey blanket and vertical cutoff. The study shows that: using clayey blanket, the maximum leaching speed occurred after 5 days, while after 10 days, it remains constant. Also conjunctive use of clayey blanket with vertical cutoff had the maximum effect on prevention of soil salinity.