Visualization of Multi-hazard Interactions in Bangladesh Through Analyzing Natural, Anthropogenic, and Technological Hazards

Bangladesh is a country that faces multiple hazards throughout the year. Those hazards can interact with each other and create complex impacts on the population, infrastructure, and environment. Though there are many discussions about independent hazards around the globe, dependence or interaction among hazards is a new concept worldwide. The purpose of this study is to make an easy comprehension of the interactions among the multiple hazards occurring in Bangladesh. This is accomplished by suggesting the distinctions between single-hazard, multi-layer single-hazard, and multi-hazard approaches which incorporate these types of interactions. This implication means that if the interactions among significant natural and man-made hazards are ignored this may pervert the purpose of management, make people more vulnerable to other hazards that are relevant to a certain location, or result in an underestimation of the risk of disaster. According to the relevant elements of a multi-hazard scenario in Bangladesh, definitions and examples of three categories—natural hazards, anthropogenic processes, and technological hazards/disasters—are provided in this paper. Based on the available literature, three categories of interaction relationships (triggering relationship, increased probability relationship, and catalysis/impedance relationship) are outlined here in detail. We tried to evaluate the interactions among the previous hazards occurring in Bangladesh by analyzing case studies using hazard interaction matrices to visualize those interactions. Furthermore, this study performs the spatial overlap and temporal likelihood analysis of past hazards in Bangladesh through the application of Overlap Likelihood Factors (OLF). The findings demonstrate that flooding possesses the highest total overall likelihood factor (OLF) among triggered natural hazards, establishing it as the most prevalent secondary hazard resulting from primary hazards, along with landslides, riverbank erosion, soil salination, and other hazards. Similarly, fire exhibits the highest Total Overlap-Likelihood Factor (OLF _T ) among technological hazards, establishing it as the most prevalent secondary hazard. the other hazards like hazardous materials, pollution, industrial explosions, and so on have respectively lower OLF _T values than fire meaning fewer interacting hazards in Bangladesh. This paper concludes by describing why understanding multi-hazard interactions is needed to contribute to the existing knowledge and practice of multi-hazard risk management in Bangladesh.