Modeling changes in the western and eastern coastline of Bandar- Jask (southern Iran) in GIS environment using the RS in the years 1989-2016

Erosion involves the retreat or advancement of the coastline, is the one of the recent problems of communities along the coast and the existing infrastructure located near the estuary system. Environmentally, coastal areas are of great importance and value due to their sensitive and productive ecosystems. Short-term or long-term coastline changes are important in the situation and geometry of coastlines and coastal management. Awareness of coastline behavior helps to manage beaches when designing and constructing coastal facilities and determining the safe margin of the coast. This article tries to modeling the changes in the coastline of East and West Bandar jask(southern Iran) in a timespan, a step towards coastal management for the planning and operation of facilities of Jask Port, which can be follow the future development of the area.

The study area is part of the coast of Jask city located in Jask county in southern Iran. For this purpose, the extent of coastline changes to determine the boundary line between land and water was examined. To be more precise, spectral operators were used in the Arc map environment and Landsat satellite imagery; the next step was to polygonize the shoreline according to the fixed landline on land. In addition, Google Earth satellite imagery was used to examine and mark some case-by-case changes, such as cape changes in the western part of the port of Jask and so on.

The dynamics of coastlines and their variability (affected by lithology and wave activity), the shape of coastlines and their effect on erosion and location of coastal sediments, resources and location of sediment accumulation and hydrodynamics of areas close to coastlines, the intensity of seasonal winds and its role in transmission Sediment transfer and erosion mechanisms, and ultimately, human activities, are among the factors influencing coastline changes. The shape of the shores was examined using the Hausdorff-Pesikovtch method. Accordingly, the rate of change in the area of polygons on the east coast (progress) is higher than on the west coast (retrograde). The reason for the progress on the East Coast could be the construction of new piers, tidal performance, the shape of the beach and how it is positioned against the waves. Overall, Oman's beaches are uplifted, which could be the reason for the retrograde; however, the drying up of the coast in order to build piers and breakwaters has led to the advance of the coast.

Prove the existence of progress on the east coast due to the construction of three new piers (after 2006) and the presence of retrograde on the west coast due to the existing natural mechanisms of the region such as the uplift of Oman coast, is the most important finding of this study. The shape of the beach and the way it escapes from the waves due to the prevailing wind direction (from the southeast) on the east coast has intensified the effect of the human factor.