EL-GAMAL, A.A., 2012. New approach for erosion and accretion coasts discrimination.

Erosion and accretion are considered as the main coastal processes. The Nile Delta is suffering from erosion due to the construction of dams and barrages across the Nile River. Detection of the coastal erosion and accretion has been carried out using different indicators. Most of these indicators require historical records for comparison. Some of these are not valid to use in front of cliffs or seawalls. Thus, the implementation of new indicators would be beneficial for coastal zone management. The aim of this work is to show that chemical indicators may be used to differentiate between eroding and accreting coasts. Dissolved inorganic silicate and suspended particulate material concentrations in seawater were selected as indicators. Data from three successive years of silicate and suspended particulate material values were evaluated for the Rashid area as an example of an erosional coast and El-Gamil as an accretionary coast. Statistically significant differences were detected between Rashid and El-Gamil according to their respective silicate and suspended particulate material values. Cluster analysis segregates the values into two separate groups (clusters). Relatively small values were contributed to the coastal erosional area (Rashid) and relatively higher values to the coastal accretionary area (El-Gamil). Validation of this method was carried out using a third location (Damietta), which is known to be another erosional coast. Cluster analysis assembled the two erosion locations (Rashid and Damietta) together and well separated from the accretionary coast. Seasonal variations in these parameters have been detected, and autumn appeared the best season for this type of differentiation.