A review on the prevention and control of flash flood hazards on a global scale: Early warning systems, vulnerability assessment, environmental, and public health burden

Flash floods' frequency and intensity are increasing because of climate change and their impact on communities. This paper aimed to critically review>100 studies about the current evidence of flash floods across different global geographies, focusing on early warning systems, risk and vulnerability assessment, attributable mortality, toxic chemical exposures, and burden of diseases. Considering the infancy of flash flood studies, early warning systems have been well studied mostly in Europe (34 %), China (30 %), and South Asia (13 %). Evidence shows an increasing risk and vulnerability to flash floods. However, there are limited theoretical bases for selecting flash flood vulnerability/risk indicators and a lack of validation of the proposed indices. It was also found that flash floods not only cause increased death among developing countries but are also associated with the incidence of water-borne (e.g., Cholera) and vector-borne (e.g., malaria) diseases. There is evidence of a release of non-threshold toxic chemical contaminants into the environment during flash floods. The study also revealed the release of high-concentration levels of antibiotics in water bodies during flash flood events. Therefore, quantitative health risk assessment and epidemiological studies recommended to understand better the long-term health outcomes associated with these exposures. We recommend that future studies consider applying evidence-based variables and high-resolution data to develop early warning systems, especially in developing countries. Incorporating technologically based early warning systems can enhance lead times and issue reliable alerts and communications while reducing the number of deaths, diseases, and chemical contaminations in flood-prone areas.