Note: PRECEDE is only compatible on desktop. Have feedback? Interested in collaborating?

Public Repository to Engage Community and Enhance Design Equity

Flooding

Flooding occurs along the coast and along riverbanks due storm events or anthropogenic climate change trends. Flooding of homes or other community structures impact both our physical and mental health through mold growth, accelerated spread of infectious disease, disruption of community, and displacement of people.
Click here for caption

Transcript: Hi, I’m flooding. I come in two different types: chronic events and acute events. Chronic events usually happen along the coast and along big bodies of water whereas acute events tend to happen along rivers and inland areas. There are many sources of flooding. A major rainstorm, hurricane, or snowstorm can cause acute flooding. With temperatures rising globally, more glaciers are melting, causing oceans to rise. And as ocean temperatures rise, the water itself expands. The impermeable surfaces in built environments can exacerbate flooding, because stormwater cannot be absorbed into the ground. When floods happen, buildings become submerged in standing water for prolonged periods of time, causing mold and destruction. Flooding harms our physical health because standing water causes mold, which is dangerous when inhaled, and standing water can also spread infectious diseases. Flooding can also be harmful to our mental health as it causes destruction of communities and displaces people out of their homes. In addition, it can cause disruption in care, food, housing, education, and employment. Historical injustices in our built environment, such as disinvestment of infrastructure have placed greater risk for flooding in some neighborhoods. Designers can help undo some of these injustices by carefully selecting materials and incorporating flood infrastructure for buildings at a higher risk.

 

Two types of flooding events:

Acute – River Flooding

Chronic – Coastal flooding

Definition

Coastal flooding occurs when water inundates or covers normally dry coastal land because of high or rising tides or storm surges. Riverine flooding is when streams and rivers exceed the capacity of their natural or constructed channels to accommodate water flow and water overflows the banks, spilling into adjacent low-lying, dry land.

Human Health Mechanism

Flooding harms our physical health because standing water causes mold, which is dangerous when inhaled, and standing water can also spread infectious diseases. Flooding can also be harmful to our mental health as it causes destruction of communities and displaces people out of their homes.

Indicator Measurement

The US Federal Emergency Management Agency (FEMA) calculates Flood Risk indices for both coastal and riverine flooding using similar methodologies. For coastal flooding, the National Risk Index calculates the number of people affected by multiplying the area of affected coastal land and the population density in that region. For riverine flooding, the National Risk Index calculates the number of people affected by multiplying the area of affected land around rivers and other non-coastal water bodies and the population density in that region.

Source of Exposures

While both coastal and riverine flooding often occurs due to discrete weather events, global climate change will consistently increase the risk of flooding due to sea level rise and global trends increasing extreme weather. Coastal flooding risks may increase due to anthropogenic climate change because as temperatures rise globally, arctic and subarctic glaciers melt, causing oceans to rise. Moreover, as the temperature of ocean water rises, the water molecules expand, serving to raise sea levels even more. Riverine flooding risks may increase due to anthropogenic climate change because current trends indicate an increase in the frequency of extreme weather, such as major rainstorms, hurricanes, or snowstorms. Finally, while flooding might be directly due to acute storm events, the damage it has on communities can be exacerbated by failures in infrastructure (i.e., levee and dam failures or poorly maintained sewage systems) and features of urban environments (i.e., increased impervious surfaces that reduce natural water absorption, contributing to increased stormwater runoff).

Related Health Outcomes & Exposures

Respiratory Diseases; Infectious Disease; Mental Illness (depression, anxiety, distress); Disruption in Care, Food, Housing, Education, Employment, and Social Network.

References

Click here for References
  1. Coastal Flooding Data Source: Climate Mapping for Resilience and Adaptation (CRMA). US FEMA National Risk Index: Coastal Flooding. Data year 2021. Accessed April 2023. https://resilience.climate.gov/datasets/FEMA::national-risk-index-census-tracts/about
  2. Inland Flooding Data Source: US FEMA National Risk Index: Inland Flooding. Data year 2021. Accessed April 2023. https://resilience.climate.gov/datasets/FEMA::national-risk-index-census-tracts/about
  3. Du W, FitzGerald GJ, Clark M, Hou XY. Health impacts of floods. Prehosp Disaster Med. 2010;25(3):265-272. doi:10.1017/s1049023x00008141
  4. Evans J. Warming Seas and Melting Ice Sheets – NASA. nasa.gov. Published August 26, 2015. https://www.nasa.gov/science-research/earth-science/warming-seas-and-melting-ice-sheets/
  5. US FEMA. National Risk Index: Coastal Flooding. hazards.fema.gov. Accessed November 10, 2023. https://hazards.fema.gov/nri/coastal-flooding
  6. US FEMA. National Risk Index: Riverine Flooding. hazards.fema.gov. Accessed November 10, 2023. https://hazards.fema.gov/nri/riverine-flooding