Flood Hazard and Vulnerability Analysis at Drainage Networks, Casae Study of Shuaibieh Plain

Flood is one of the most terrible natural disasters in the world, flood damages leave long-term damages in various sectors, especially agriculture. Hazard analysis and vulnerability assessment is one of the primary steps in flood disaster management. Although such studies less done in irrigation networks. In this research, hazard analysis and vulnerability assessment has been done for the irrigation network in the east of Shuaibieh plain. It is an important irrigation project of Khuzestan province, and its flood will cause irreparable damages to the farmers and residents. For this purpose, hydraulic simulation has been done in Hec-Ras-2D and for 25, 50, 100 and 200 years return periods. The extent, inundation depth and flood velocity were extracted from the model. Using the model outputs and with the aim of existing standards, flood hazard maps have been drawn. According to these maps, for each flood with a return period greater than 50 years, more than 50 percent of the Shuaibieh plain is at unsafe level for all people and structures. By using the prepared questionnaires from 42 local farmers and irrigation network operators, various vulnerability indexes (economic, social, environmental, resilience, and flood magnitude) were estimated and by Analytic Hierarchy Process of them, the vulnerability was assessed. Finally, with superposition of each vulnerability index map, the total vulnerability map of the plain against floods was drawn. The highest and lowest levels of vulnerability are related to coping capacity index with 33.7 percent and social index with 9.6 percent, respectively.