LAUSR

Abstract The impact of water-related disasters has become more acute in cities of the Amazon Basin. Socio-economic impact assessments have a key role in improving sustainable mitigation projects in order to increase resilience and reduce societal vulnerability. This paper reviews the current state of loss assessments and then explores how to improve estimates for the 2015 flood affecting the city of Rio Branco, Brazil, located on the headwaters of the Amazon Basin. Prevailing models, loss assessments, and databases are not applicable in this Amazonian context due to the lack of detailed cost administration, low levels of human and financial capital, and limited insurance coverage. This paper uses uncertainty ranges of the costs of water-related disasters to provide an assessment of the total impact. Our estimate ranges from 60 to 200 million USD of losses and damage solely due to this flood event, compared to the official estimate of 98 million USD. As floods in Rio Branco are recurrent nearly annually, the cumulative losses over the years may be significantly higher. Our study illustrates the need for improving impact assessments in order to increase the knowledge on the actual costs of flood disasters and avoiding silent impoverishment. Outcomes of impact assessments can show the necessity of mitigation activities which will reduce vulnerability of societies.