عنوان مقاله [English]
Mass movements are all the movements that occur on mountain sides because of the gravity of earth. These movements are divided into different types such as falls, slides, creeps, solifluction, flows, etc.
In some areas these movements and their consequent erosion play greater role in sedimentation and changes in shape of slopes than other types of erosion. Although human casualties caused by such movements are not vast, but these movements inflict colossal damages on the country’s lands and infrastructures every year. For example, these movements bring about one billion dollars of damage to national lands and infrastructure in the United States every year. In our country, the share of mass movements in annual damages have been estimated as about five hundred billion rials (Ministry of Interior’s National Committee on Natural Disaster Reduction,1994).
On the other hand, identification and study of these movements requires equipment and implementation of certain methods. One of the best and simplest tools for such aims is aerial photography.