A parsimonious approach to mapping climate-change-related composite disaster risk at the local scale in coastal Bangladesh

Abstract Climate-change-induced disaster risks impede sustainable development goals in many developing countries. With the prevailing climate change conditions, environmental events are likely to become even more pervasive. Coastal regions, the source of numerous tangible and intangible benefits for human populations, are exposed to a wide range of risks. With the motivation that knowledge of risk at local levels could bring substantial benefits for risk reduction planning, the current study devised a framework for mapping composite disaster risk at the local-scale using context-specific risk variables and tested it within a clearly defined coastal sub-district of southwestern Bangladesh. Utilizing easily accessible spatial and non-spatial secondary datasets, a risk map for the study area was formulated using geospatial techniques. The map revealed that within a small area of about 230 km2, the risk of disaster varied considerably, which is attributable to the variability of geographic and socio-demographic features of the area. The map delineated 21% of the study area as very high risk, 20% as high, 21% as moderate, 20% as low, and 18% as very low risk. The technique for risk mapping adopted in this study is inexpensive to conduct, doable within a brief period, requires limited data inputs and is thus usable for countries like Bangladesh that have a dearth of data. The resulting map is an improvement over existing risk maps, which are currently available only at the regional scale and hence provides a robust platform upon which to commence the process of disaster risk reduction in the area.