Flooding and health: summary of two scoping reviews of the literature

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Introduction

Climate change is expected to increase the frequency of flooding in the United Kingdom, with Wales being particularly vulnerable. Flooding poses significant short- and long-term challenges to peoples physical and psychological health.

To shape Public Health Wales’ future climate change research agenda, two scoping reviews were conducted to explore:

1. the effectiveness of flood early warning systems in mitigating the health impacts of flooding, including any adverse consequences; and 
2. the effectiveness of psychosocial interventions in supporting mental health and wellbeing in areas at risk of flooding or after a flood has occurred.

Main points

How up to date is this evidence?

These scoping reviews were conducted in 2024 and include research from 2004 to 2023.

What we found

In the first review, seven studies were identified which examined the effectiveness of flood early warning systems on health outcomes such as death, physical injury, and post-traumatic stress disorder. Results were mixed as to whether receipt of a warning had a mitigating effect on the health of people who experienced flooding. However, some research suggested that for those who received a flood warning, the greater the warning time, the lesser the negative health effects. Most studies had methodological flaws, lessening confidence in the findings.

In the second review, three literature reviews and one guideline examining mental health interventions post-flooding were identified, though the quality of these was limited. The reviews suggested that most psychological needs post-flooding can be met through family and friends but that some individuals may need more specialized support, with UKHSA guidance recommending a four-tiered approach for reducing the mental health effects of flooding. No reviews were found that examined interventions for people in areas at risk of flooding.  

What this means

Both reviews highlight significant gaps in the evidence base, with a lack of high-quality secondary evidence on the effectiveness of interventions for mental health support in areas at risk of flooding or post-flood. Additionally, the effectiveness of flood early warning systems on health outcomes is under-researched.

Technical information

Agile scoping reviews utilise rapid methodology to provide a broad overview of the evidence base on a topic of interest. They are intended to guide and inform further work rather than to be used for policy and practice. Factors relevant to answering the above question identified from the studies have been extracted and briefly summarised within this report. If a specific factor is of interest, it is advisable to read the sources from where they were taken in more detail.