Study of the Goals and Methods of Landslide Risk Zoning in Taleghan Watershed during the Last Two Decades

Landslides are one of the most important factors in the destruction of watersheds. The frequency of landslides is higher in sloping and wet slopes consisting of sensitive formations or due to human activities. Taleghan watershed is known as one of the most prone landslides in the southern slopes of Alborz mountain range, despite the significant area of Miocene marls and high natural humidity due to high density of drainage network and construction of Taleghan dam. A review of the records of studies related to the Taleghan watershed shows that older studies have been done with simple and qualitative tools and based on the experiences of experts, while today these methods have given way to quantitative statistical studies and methods based on machine learning. The evolution of landslide risk zoning tools in Taleghan also demonstrates this importance. In this study, while reviewing the research objectives, we have reviewed the application of methods over the past two decades and after reviewing 15 separate research articles, the evolution of landslide risk zoning tools in the Taleghan watershed has been investigated. The results showed that statistical models were better and more applicable than innovative models and qualitative and semi-quantitative methods, but it is noteworthy that the speed of using methods based on machine training and fuzzy logic was higher and This result is clearly seen in studies conducted in this basin (especially during the last five years).