The Effects of Sea Level Fall on the Caspian Sea Shoreline Changes

Abstract

Article History: Received: 24 May 2018 Accepted: 26 Nov. 2018 The Caspian Sea level has experienced frequent fluctuations resulting in shoreline advance and retreat. Therefore, studying and predicting shoreline changes in the Caspian Sea are very important. The "Bruun Rule" was presented in order to predict shoreline variation due to sea level rise. In addition, to improve the predictions of the Bruun rule, added landward sediment transport to it, leading to more desirable results. In this research, the Bruun rule and its modified form, extended for landward transport, were investigated for the Caspian Sea level fall conditions. The modified equation in this study leads to the better results, which indicates that due to sea level fall and natural storms, there would be sediment deposition toward the shoreline. In terms of water level reduction, by applying the coefficient, the root mean squared error was obtained 3.447 meters for predicting shoreline changes in comparison to its natural changes. According to the results, the lowest difference in prediction is related to the Mahmudabad coast and the highest difference in prediction is related to the Dastak coast, which are equal to 0.059 and 4.849 meters, respectively. Based on this trend for forecasting