عنوان مقاله [English]
Boundaries are geostrategic and geopolitical phenomena that are constantly undergoing changes when accompanied by natural disasters. Today, states carefully mark and mark the border to avoid disputes. Therefore, it is necessary to identify and plan for these changes through the new tools and techniques needed to address this political dilemma. River and watershed of Sumbar (Perce Su) is one of the tributaries of Atrak River that has been changed by periodic floods and has caused many problems for the residents of this area. In this study, using topographic maps, geology, digital elevation model and Landsat satellite imagery, 1987 and 2017 and Indian RS satellite image 2008 and Auto CAD, ENIV and Arc map software, accurate river bed determination and river bed morphometric parameters It was calculated in two intervals. Subsequently, changes in the bed of the Sumbar River were analyzed and evaluated based on field surveys as well as geological and land use changes. Calculations show that the length of the Sumbar River in 1989 was 48.58 kilometers, which decreased to 48.46 kilometers in 2008 and to 47.29 kilometers in 2017, the mean central angle of the Summar River twists 83. / 40 degrees in 1987, reaching 36.27 degrees in 2008 and 30.61 degrees in 2017, which is higher than in the second. The number of twists and turns in 1987 was 154, down from 144 in 2008 and 136 in 2017. According to the findings, a large part of the Iranian coast of Sumbar is being eroded by the river, and measures such as bed reinforcement and artificial bedding are inevitable. However, it is recommended that these measures be in accordance with river hydrodynamic conditions.