Geomorphic Analysis in Determining Coastal Cells and Its Role in Coastal Management(Case Study: Bandar Anzali to Chalous Coasts)

Due to the different geomorphological and morph dynamic forces of the coastal area, they form different areas. Each of these areas requires its own coastal management. While in our country, coastal management is done without considering the characteristics and coastal characteristics of each coast. In this study, in order to classify coasts and determine coastal cells, morph dynamic effects and sedimentary structures of riverbeds and seas have been used be taken; therefore, we are looking for the answer to the question of what are the coastal cells between Anzali port and Chalous and what are the boundaries of ta separation of these cells? And what are their uses in coastal management? The problem-solving method and answering research question is quantitative and using geomorphological and marine hydrodynamic data.     

The study area is the distance between Bandar Anzali in Gilan province and Chalous city in Mazandaran province. Research data include geological data, river hydrodynamic data (annual flow and sediment discharge), marine hydrodynamic data (current and direction of the wave), regional elevation model (DEM) 12.5m, surface morphometric and topographic data including slope and gradient direction, surface data, the sea level is the active sedimentary depth data, the sedimentation of coastal sediments and the field observational data. The research tools included geological maps of 1:100000, topographic maps of 1:25000, images of sentinel 2 satellites, sedimentation models of hydrometric stations, high-speed wave data of Anzali port, Rudsar and Chalous. In the method of data analysis, first, the hydrometric characteristic (flow and sedimentation) of rivers and coastal sedimentation models using excel and GIS software. In the step, the determinants of sedimentary cell boundaries were consolidated. At this stage, the boundary separating boundaries that distinguished those from each other in terms of the mentioned features were drawn and the main sedimentary cells were determined. In the final step, the boundary of the cells on land and sea was determined. At this stage, for each cell, the cell boundary at the post cranium and its boundary at sea were determined.  

The results of the overlap model showed that the range between Anzali port and Chalous consists of 4 main cell and 9 sub cells.  The first main cell is between Chalous port and Ramsar beach. The main characteristics of this cell are the change in the direction of flow after the failure of the wave to the east. The sedimentary reservoirs of this cell and the sediments of the rivers are lower than other cells, and the slope of the coast in these cells is higher than the other shores of the study area and research 1.1%.  The second main cell is the Ramsar cell to the clutch. Characteristics of this cell include the high rate of sedimentary inflow from the rivers in this cell and the flow of sediment rotation to the east are the main characteristics of this cell. Also, most of the river sediments in this cell are moving to the east and have accumulated in the distance between the estuary of the river and the middle of the Chabaksar to Qasemabad route. The third coastal cell is between Kalachai Rezamahleh and Amirabad region. In this part, due to the increase in altitude due to Alborz Mountain and the sudden increase of the slope and hard post-coastal formations, the coast has a small area. Also, the height of the wave and the direction of flow are to the west and move parallel to the shore. The boundary between the two cells in Kiasar is a man-made and rock-forming structure, but in Amirabad there is a sudden change in slope and a change in the direction of flow. The fourth cell is between Amirabad nose and Anzali port (Caspian port). In this cell, the main sand formation and most of the formations are composed of low plains and sedimentary plains resulting from sediments of Sefidrud River. In this cell, the movement of the current after the break of the wave is towards the west and has caused the sediments to move from the estuary of the rivers to its west. Also in this cell, due to the high flow and sedimentation of Sefidrood River, a wide area of ​​the coast is covered with ridges and coastal sands.  

According to the research results, the sandy shores of the Sefidrud River and other rivers on the shores of Bandar Anzali to Chalous are among the most widely identified types of landforms. Only in Chalous, due to the high population density and low shoreline, human sandstones have undergone more changes than human and coarse-grained sands. Therefore, due to the fact that most of the study area has a high population density and also the lowlands of these areas have a small slope and height, if the climate changes and sea level rises with dangers such as flooding of lands and infrastructure. Coastal buildings, the destruction of various residential, industrial, office, educational and other facilities and buildings also threaten it. It is worth noting that the complexity of natural, physical and human activities in the coastal area makes it difficult to manage it, because this complexity has caused and will cause many problems in the coastal areas.