Investigating the Role of Continuity of Phenomena and Natural Disasters on the Decline of Agricultural-Economic Activities in Sistan of the Islamic Period Based on Local Texts

Sistan is a large and extensive land that throughout history in the field of livelihood, economic and agricultural activities such as "Khorasan bread warehouse and breadbasket" has had ups and downs. The economic and agricultural decline of Sistan in the history of post-Islamic Iran will be addressed using library tools and historical-analytical research methods. Considering the issues raised, the main question of the present study is: What are the causes of the stagnation of agricultural production and economic decline in Sistan in different Islamic periods caused by what phenomena and natural disasters? Comparative studies of the research based on local and geographical historical texts such as: "History of Sistan and the revival of the kings and the genealogy of the kings" show natural phenomena such as: severe erosion in Sistan, the presence of branches, the phenomenon of quicksand, 120-day winds in Sistan, successive droughts, famine outbreaks, cholera and plague are caused by human activities, and subsequently the destruction of farms has been directly and indirectly related to the economic and agricultural recession in Sistan. Other factors affecting growth and The spread of natural disasters by the Mongols and Timurids in this region had a significant impact on the decline in production and economic activities, and the adverse consequences of this siege, many dams, damaged water structures and the ground to reduce the loss of economic and agricultural activities.