The analyze of Effective Morphodynamic Processes in Caspian sea shoreline changes ( case study: Karkanrod delta river) West of Gilan

Shorelines are very dynamic geomorphic systems where continuous changes occur at differents spatial and temporal scales .Coastal sustainable management, need to know the trend of sea level changes, showing of shoreline changes can ensure coastal relative sustainable for performing plan coastal environmental management. Case study is shoreline of Karkanrod estuary that is located in the west of Gilan between eastern longitudes 48°-34ʹ to 48°-58ʹ and northern latitudes 37°- 42ʹ to 37°-57ʹ.The aim of this research is to extract shorelines from past to now, determine effective land and hydrodynamic processes in the morphologic changes of Karkanrod delta shoreline to assess the rate of shoreline changes and their reasons. Waves and wind data, hydrodynamic data such as sediment and water, sea level fluctuations ancient graphs, Landsat satellite images, Aerial photos were utilized to study shoreline changes that show progress and regress of karkanrod delta. The method used in this research, is a combinational of, descriptive and analytic method with field and library studies.In field observation, some Geomorphologic evidence in the study area such as: V-shaped valleys, fluvial terraces and loesses were identified, that rectify the effect of active tectonics and sea level changes in the region. DSAS method was used to extract shoreline changes in different times.The results of this study show that the shoreline of Karkanrod delta experienced the most erosion during 1985-2000 and the most accretion during 2008-2017. Relative sea level change plays an important role in the shoreline of karkanrod delta. Transects of 7, 8 and 9 that are almost in the center of delta, where the karakanrod estuary is located, have more accretion rate that it shows the effect of sediment rivers. The results and methods may be helpful in coastal management and understanding the evolution of the entire delta from the perspective of shoreline change.